fantasy book covers

Jul. 19th, 2017 07:44 am
[syndicated profile] lois_mcmaster_bujold_feed
Heh. This amused me...

https://thoughtsonfantasy.com/2017/07...

Also, the number of people in the comments who said they'd totally read it...

I swear, the ill-fated "Pillsbury Nazgul" British cover for Paladin of Souls ticks almost all of the boxes.

Ta, L. Easily amused this morning.

posted by Lois McMaster Bujold on July, 19

Garbage poetry

Jul. 19th, 2017 10:39 am
mount_oregano: Let me see (Default)
[personal profile] mount_oregano

“Garbage” is the theme of the current issue of Eye to the Telescope, a quarterly online journal of the Science Fiction & Fantasy Poetry Association. I’m a member, and as such, I’m pleased to invite you to enjoy the July 2017 issue.

It offers 19 speculative poems dealing with such refuse as socks, landfills, trashy novels, and star dust.

Read it here:
http://eyetothetelescope.com/archives/025issue.html

— Sue Burke
[syndicated profile] badastronomy_feed

Posted by Phil Plait

The European Space Agency’s current ExoMars mission has had a bumpy ride from the third to the fourth planet from the Sun, but right now things are looking good.

Launched in 2016, the mission had two parts: The Trace Gas Orbiter (or TGO), which was designed to orbit Mars and investigate the planet’s atmosphere, and the Schiaparelli lander, which was mostly a technology testbed to better understand how to land robotic explorers on Mars. NASA has done the latter many times — not always successfully —  but ESA hasn’t done so yet.

TGO is doing fine. It was initially on a long, elliptical orbit around Mars (the easiest kind to establish upon arrival) but has been executing a series of short engine burns that drop the low point in its orbit (called periareion, for “near to Mars”) into the upper parts of the atmosphere. That causes drag with the thinly distributed molecules there, taking energy away from the spacecraft’s orbit, lowering and circularizing it. Called aerobraking, this maneuver will eventually put TGO into a circular orbit at a height of about 400 km above the surface. The spacecraft will then orbit the planet once every two hours or so.

That will happen in 2018. Right now, it’s still in the elliptical orbit that stretches from about 200 km above the surface to 33,000 km out. That’s still a useful path! For example, it passed about 7700 km from the Martian moon Phobos, and dusty, battered space potato of a satellite, and took this pretty nifty image in October of 2016:

Phobos

Phobos, one of the two small moons of Mars. It’s about 27 km across through its long axis. Credit: ESA/Roscosmos/CaSSIS

It also has been observing the thin air of Mars, detecting carbon dioxide (the major component) as well as small amounts of water vapor. Eventually it will look for traces of methane, which has been positively detected in the Martian atmosphere but is poorly understood. On Earth, the major source of methane is biological activity, including livestock (by, um, outgassing) and human activity, including production and use of coal. It’s a greenhouse gas, but methane molecules are fragile and tend to react easily when oxygen is present. In Earth’s air the amount of methane is more or less stable, with the destruction of the molecules balancing their creation. That’s good, because methane is a very strong greenhouse gas, stronger than CO2.

Its presence on Mars is more difficult to explain. It’s due to some sort of geological process, but just what isn’t well known. TGO will map its concentration and location, hopefully providing needed clues to the gas’s origin.

Mellish crater

TGO mosaic of part of Mellish Crater, a 100 km wide crater near the Martian south pole. It was assembled from 40 images taken on March 5, 2017. Credit: ESA/Roscosmos/CaSSIS

Things, however, are not so good for the Schiaparelli lander. In fact, that part of the mission, in some sense, ended before it really began: It crashed into the planet on October 19, 2016, instead of softly touching down.

The crash investigation recently ended, and they found that a confused measurement device on board Schiaparelli instigated the impact. The lander deployed from the orbiter cleanly on the way to Mars. As the lander entered the upper atmosphere, the parachute also deployed as designed. However, it caused the lander to vibrate, or oscillate, for a few moments. A device called an inertial measurement unit confused that motion for a rotation of the spacecraft and got a reading far higher than it was designed for. It saturated, basically pegging the needle.

This only lasted for about a second, but that was enough. The odd reading was interpreted by the lander as its being upside-down, and the software wasn’t designed to handle that. When it did the math, it incorrectly calculated that it had a negative altitude, and so it interpreted this as being on the surface. It ejected the parachute and fired its landing thruster, but it was far too early and for too short a time.

This happened while it was still 3.7 kilometers (over two miles) above the surface. It free-fell the rest of the way, impacting Mars at a speed of 370 km/hour — nearly four times faster than a car on the highway. It didn’t survive. The impact scar and debris have been spotted by other orbiters.

Schiaparelli crash site

The Schiaparelli crash site, imaged by the Mars Reconnaissance Orbiter in November 2016. The surface disturbance is obvious, and the brighter dots around it may be debris from the spacecraft. The image is about 234 meters on a side. Credit: NASA / JPL / UA / Emily Lakdawalla

The good news is that the engineers learned a lot from the event, and won’t make those same mistakes a second time. In fact, they’ve said that some of the errors leading to the crash wouldn’t have been detected if the lander had made it down safely, and that could have led to disaster on a future mission. Since Schiaparelli was designed to test the hard- and software, in one way, this was fortunate. Better Schiaparelli than a far more sophisticated and expensive science lander.

Not that this crash was a good thing, but when it comes to space travel, every mistake is a chance to learn. At least, in this case, the loss was minimized.

Mars and the Sun
In mid-July 2017 Mars and the Sun are very close together in the sky. Credit: Sky Safari

Right now, Mars is nearly on the opposite side of the Sun as seen from Earth. Our orbit is closer to the Sun, and faster. Once every 26 months or so, we pass between the Sun and Mars, and then, roughly 13 months later, the Earth is on the opposite side of its orbit from Mars (remember, Mars moves, too, so it takes a while for us to pull ahead); this means that, from Earth, Mars and the Sun are very close together in the sky (called solar conjunction). That means it’s more difficult to communicate with spacecraft there — the Sun is the brightest radio source in the sky — so TGO has been commanded to sit tight in its current orbit for now. In a few weeks, it’ll start dipping its orbit again, hopefully on its way to a nice, stable circular science orbit.

It joins a veritable fleet of other robotic craft there, including some from the U.S., one from India and another by the ESA. It may be quite some time before humans go to the Red Planet, but our uncrewed proxies are still working apace. Mars is dry and cold and probably lifeless, but that doesn’t mean it’s not a dynamic and interesting world. I’m glad humans all over our planet are still interested in exploring it.

[Top image: ESA/ATG medialab]

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[syndicated profile] sfwa_feed

Posted by Editor

by Jennifer Brozek

As of 1 July 2017, I stepped down from a two year stint as a Director-At-Large for the Science Fiction and Fantasy Writers of America (SFWA). My term was up and I chose not to run again (this time) due to life happening around me. I learned so much from the organization and from the other Directors themselves. I also learned a lot from the SFWA membership through the lens of a board member. To make things easy on me, I’ve distilled it all into the 10 Things I Learned While I Was A Director-At-Large for SFWA.

10: It was one of the most rewarding volunteer positions I’ve been in.

I worked with a stellar team of people I wouldn’t have had a chance to work with before I stepped up to the plate. Being a Director-At-Large gave me an inside view on how SFWA works, its goals for the organization, how to help its membership and writers all over the world as well as allowed me to help shepherd some large projects towards fruition. Watching Game Writers be admitted to SFWA was beyond awesome. It was one of my goals from the moment I became a member of SFWA. Watching the Speakers Bureau come online in a working capacity was very fulfilling. Instituting the first board member “office hours” was a thrill. Streamlining the EMF process is still in progress, but I know I’ve done my part. When you work on the Board of Directors, your work changes the organization.

9: It was one of the most difficult volunteer positions I’ve been in.

There are good and bad things that happen when you lead by committee—especially a committee of volunteers. When one committee talks to another committee, things move at a (perceived) glacial pace. It makes it difficult to know when to poke someone (or a committee) for an answer you are waiting on. Make no mistake, SFWA is governed and run by committee. We have a President who focuses our tasks, puts out fires, pokes committees for you, but… you’re still working with a series of committees made up of volunteers with different wants/needs, different communication styles, different time allotments, different backgrounds, and different perspectives. This makes it hard. You can’t push too much. You can’t not push. Everything is a delicate balance between need, time, and availability. The entire time you work on SFWA’s Board of Directors, you try to keep this in mind. Sometimes you fail. Most of the time you succeed. You’re going to remember the failures more.

8: The Board of Directors has their hands full.

There are so many projects and concerns that that Board of Directors handles that every single board member is busy. Really busy. Each one is a point of contact to every single committee SFWA has. There are five main areas that SFWA focuses on: Support, Promotion, Information, Defense, and Advocacy. I’m linking the info graphic that describes each one. For every single bullet point, someone in SFWA has championed that project and a board member has been or is a point of contact. The Board works for SFWA and its members. It also works to promote the welfare of all writers.

7: The Board of Directors frequently has their hands tied.

SFWA is a 501(c)(3) organization. As a nonprofit organization, there are a number of specific rules and restrictions SFWA must follow. As an organization incorporated in California, there are a different set of rules and regulations SFWA must follow. As an organization with a specific set of goals—the promotion and advocacy of authors—the organization itself has created and voted on a third set of rules and restrictions SFWA must follow. All of this means when someone brings up an issue involving everything (but not limited to) money, donations, charity, advocacy, state or federal laws, taxes, theft, slander, or plagiarism… there are so many hoops, rules, restrictions, and laws that must be checked before the Board can act.

Not only that, when it comes to individual conflicts, there is a specific jurisdiction SFWA can work within: Did the incident happen at a SFWA sponsored event/green room/panel? Did the incident happen using SFWA resources? Did a SFWA member use their membership/position in SFWA to incite/abuse/manipulate? Is the complaint specific enough? Does it an individual or a large numbers of authors?

These are the kinds of questions we must ask before we act. More often than not, we need to refer complaints to various internal committees, have private, unofficial conversations with individuals, or make blanket statements that SFWA does not approve of a specific action. Sometimes, there’s nothing the Board can do except lend emotional/moral support.

6: Authors, even your favorite author, are only human.

Everyone has either heard the story, or experienced it themselves: “I used to love reading AuthorX, but then I met them and discovered they are terrible. I can’t read their work anymore.” Sometimes it is hard to discover your idols are human with human wants, needs, foibles, opinions, habits, and flaws. When you work on SFWA’s Board of Directors, you usually see all the behind-the-scenes stuff.

Sometimes, you work with an author/editor on a SFWA project and it doesn’t go as smoothly as you like. Sometimes, it appears as if an author once admired has nothing but scorn for the work you are doing and no desire to help out—just kvetch and complain. Sometimes, authors come to the Board at their worst—financial or medical difficulties, personal conflicts that threaten to spiral out of control, issues with editors, agents, or publishers. They don’t have their “public face” on. They are human. They make mistakes. They can be hurt. They put their pants on one leg at a time.

This is one of those learning lessons that really surprised me. I’m not sure why. I just know it did.

5: Discretion is the better part of valor.

With everything I’ve mentioned so far, one of the most valuable things a Director-At-Large (all the board members, really) can do is keep their ears open and their mouths shut. More than just listening, there is a compact with the membership that when an-all-too-human author comes to us with an issue, that issue remains private until it is decided amongst the board and the member themselves that the issue can go public. There are many issues brought to board members that have nothing to do with SFWA, but board members are in perceived positions of power and sometimes, authors just need an authority figure to listen and unofficially advise. They also need to know what they are saying will remain on the down low.

4: Volunteers are the lifeblood of SFWA.

You get out of SFWA what you put into it. SFWA is an organization of the members and for the members. By extension, SFWA works for the betterment of all authors. Volunteers are SFWAs lifeblood. There are only so many things the Board—who are all volunteers—can do at one time. If you see something that’s wrong or lacking in the organization, speak up and step up. The Board loves nothing more than a motivated volunteer. If you don’t know what needs doing, we have a Volunteer Coordinator who would love to put you to work. We have various committees that need people. Need you. You will learn more about SFWA, the industry, and yourself when you volunteer at SFWA. It will help you feel more connected to the membership and the industry as a whole.

3: Patience is a virtue.

As SFWA is a volunteer organization, there is only so much pushing one can do. Even if you are waiting on something from someone else before you can get your project moving/done, you must remember that volunteers have other jobs, other duties, and other deadlines. In all cases—working on projects, listening to incident reports, just checking in on the membership, reading the forums—patience is a virtue. Slow, deep breaths. Be clear and concise in your communication. Give specific timelines, concrete tasks, and manageable goals; even to yourself. Especially to yourself. Know what you need and move at a steady pace.

2: The Board of Directors is made up of good people.

I’ve never worked with such dedicated people before. Every single one of them works hard and wants to do good by the membership. Every single one of them puts in hours of work each week. They seriously discuss every issue, try to consider all angles, and do their best to work within the rules. Though we haven’t always agreed on everything, I’m proud to have worked alongside them. I feel safe and secure knowing that the people making up the Board is there. I didn’t even feel guilty (much) for stepping down. The new people who stepped up are competent and knowledgeable.

1: I will probably run for the Board again—sometime in the future.

While life is at a point where I don’t have time to be on the Board, I am still working on specific projects for them. I will probably run for the Board again in the future. I know (mostly) what to expect and still believe that not only is volunteering for the Board a worthwhile endeavor, it’s one that everyone should try to experience at least once during their time in SFWA.

•••


Jennifer Brozek is an award winning author, editor, and tie-in author. Two of her works, Never Let Me Sleep and The Last Days of Salton Academy have been nominated for the Bram Stoker Awards. She was awarded the Scribe Award for best tie-in Young Adult novel for The Nellus Academy Incident. Grants Pass won an Australian Shadows Award for best edited publication. In-between cuddling her cats, writing, and editing, Jennifer is an active member of SFWA, HWA, and IAMTW. She keeps a tight writing and editing schedule and credits her husband Jeff with being the best sounding board ever. Visit Jennifer’s worlds at jenniferbrozek.com.

 

 

[syndicated profile] badastronomy_feed

Posted by Phil Plait

Today, some bittersweet spacecraft news: The LISA Pathfinder mission is shutting down. That’s always a bit sad, but in this case, in sum, it’s actually good news: That’s because it accomplished all its goals. And even better, it means that a bigger, beefier mission will take its place! That mission, called LISA, was recently approved by the European Space Agency to continue its planning phase, aiming for a launch in 2034.

Why am I happy about this? Because LISA is the Laser Interferometer Space Antenna, and it will use what is essentially Star Trek technology to detect merging black holes all across the Universe.

So, yeah. How awesome is that? And, for a while, I feared it would never get off the ground. It hasn’t yet, but the odds are looking much better now.

OK, you probably want a modicum of background here. I’ll be glad to help.

Maybe you’ve read reports about LIGO, the Laser Interferometer Gravitational-Wave Observatory, which recently detected black holes merging for the third time. I wrote about that event and gave a lot of background a couple of years ago when LIGO bagged its first black hole coalescence.

In a nutshell, one of the predictions of Einstein’s Theory of Relativity is that when matter is accelerated it creates ripples in the fabric of spacetime, much as shaking a bedsheet up and down causes ripples in the fabric. These ripples are stronger if the objects are very massive, very dense and accelerated very rapidly.

You don’t get more massive, more dense and more accelerated things in this Universe than two black holes at the very moment they eat each other.

 

There are a few ways this can happen. Probably the most common is from black holes that form when massive stars explode. If those stars are orbiting each other in a binary system, then, eventually, after both stars blow up, you get two black holes orbiting each other. As they emit gravitational waves — those Einsteinian spacetime ripples — they spiral in toward one another. Over a long time (usually billions of years), as the distance between them closes, they orbit faster and faster. Then, finally, accelerating each other to very nearly the speed of light, they merge into a single bigger black hole, emitting a fierce, sharp blast of gravitational waves.

These ripples in spacetime then move across the Universe at the speed of light. When they wash over our planet, they physically compress and expand space itself. The effect is incredibly tiny by the time these waves reach us: A typical ruler would only shrink or expand by a tiny fraction of the size of a proton! But these effects can be measured because we are very clever apes, we humans.

LIGO was built to find these ripples, and after decades of trying, it works! It can now feel the Universe shake as black holes collide.

Merging black holes art

 

But LIGO, as amazing as it is, isn’t nearly as sensitive as what’s possible. Enter LISA.

LISA is similar to LIGO, but it’ll be in space. There are lots of advantages to this. For example, LIGO is so sensitive it has to worry about individual oxygen atoms hitting its mirrors, distorting the signal. In space there’s no air, so that’s an improvement.

Also, this stretching of spacetime is easier to measure if you have a longer baseline. If your detector is short it only stretches and contracts a little bit, but if it’s 10 times longer the effect is 10 times bigger. LIGO has mirrors spaced a few kilometers apart, making it highly sensitive. Because LISA is in space, its detectors can be much farther apart. In fact, the plan right now is for the components to be separated by about 2.5 million kilometers!

If you want to think of it as sound (which it isn’t, but the analogy isn’t bad), LIGO can hear the loudest black hole mergers. LISA will hear the whispers. In fact, it should also be able to detect mergers between neutron stars and even white dwarfs, which are far “quieter” than their denser black hole brethren.

So, how does it work? LISA is actually three disc-shaped spacecraft, launched together on one rocket. They each have an onboard propulsion system that will move them to their final separation of several million kilometers, forming an equilateral triangle in roughly the same orbit as Earth, but 20 or so million kilometers away from us.

Like LIGO, LISA will use lasers. Each spacecraft will have onboard two lasers, each of which will fire at one of the other two spacecraft. Using a technique called interferometry, the distances between the spacecraft can be measured with utter precision:

 

But there’s a problem with this. The spacecraft need to be able to measure their relative positions with incredible accuracy, so that the teeny tiny effects of a passing gravitational wave can be measured. But there are lots of forces in space that would totally wash that out. Tides from the Earth, Moon, and Sun, cosmic rays, solar wind and more would all be far stronger, moving the spacecraft around and ruining the measurements.

To overcome this, inside each laser assembly is a small, exquisitely crafted cube made of gold and platinum (yes, seriously; they’re very stable and that makes them useful). Each cube, called a test mass, is about 4.5 or so centimeters on a side and has a mass of about 2 kilograms. They are totally disconnected from the LISA spacecraft, untouched by it in any way, allowed to float completely freely. The tolerance is extreme: No force on the cube is allowed more than about that exerted by the weight of a bacterium.

See what I mean by Star Trek technology?

LISA spacecraft

Artwork showing one of three LISA spacecraft “connected” to the other two (one above and to the left, the other off screen to the left; both 2.5 million km away) via lasers. Credit: AEI/Milde Marketing/Exoze

 

In this way, the cubes are freely floating in orbits around the Sun, and the spacecraft keep position around them. Using extremely sensitive sensors, each spacecraft keeps itself precisely aligned with the cube inside it, measuring their exact location at all times. 

The cubes act as benchmarks for the spacecraft around them. As long as the cubes are allowed to move freely, then a gravitational wave passing through them would change their relative separation, allowing it to be detected. The spacecraft act like shields, preventing outside forces from affecting them … really, these forces affect the spacecraft, which then use incredibly low-thrust engines to maintain their strictly controlled positions. If there’s a force on the spacecraft, say the solar wind, then the thrusters counteract that to make sure the spacecraft stays perfectly centered around the cubes. And I do mean weak: It would take a thousand of these thrusters to generate the same weight as a piece of paper in your hand!

LISA test mass

The LISA Pathfinder test mass, very similar to the ones that will be used on LISA. It's a cube of gold and platnium with a mass of about two kilos. Credit: RUAG Space, Switzerland

 

I like to think of all this using an odd analogy: curling. That’s a sport played on an ice lane where a player throws a heavy mass (called a stone) and tries to place it in a target area downrange. Other players, called sweepers, have brooms and they rapidly sweep the ice ahead of the stone, decreasing the friction and making sure the stone’s trajectory is true.

For LISA, the test masses are the stone, and the sweepers are the spacecraft. They never touch the stone, but they make sure its path is true.

Now, if a gravitational wave passes through the LISA spacecraft, the pattern of light created by the laser changes, and this can be measured with ridiculous accuracy. Even though they will be separated from each other by a distance several times greater than the distance of the Moon from Earth, they will measure their relative positions to an accuracy of a few trillionths of a meter. Yes, trillionths. For those who love words as much as I do, a trillionth of a meter is a picometer. Feel free to work that into your next conversation.

And, again, this exemplifies the idea of how astonishingly advanced this tech is.

This brings us back to LISA Pathfinder. We know all this technology needed for LISA will work because the European Space Agency successfully tested it using Pathfinder. It launched in late 2015 and was equipped with lasers, cubes and other bits of tech LISA will utilize to measure the whisper from colliding hyperdense cosmic objects. It was amazingly successful and completed its mission on June 30. Today it will be shut down, having paved the way for LISA to continue.

I’m glad this is happening. Many years ago, NASA was partnered with the European Space Agency to help build LISA. I actually worked a bit on the Education and Public Outreach for the mission, writing up descriptions of how it worked and what it would do. But shortsighted budgetary decisions meant NASA had to pull out of the development, which upset me greatly at the time.

However, over time and with a lot of cajoling by scientists, the U.S. has rejoined the mission as a senior partner, with the ESA leading the way. I’m very glad to see this. Now that LIGO has shown we can detect gravitational waves, and LISA Pathfinder has shown the advanced technology is possible, LISA itself will open the floodgates of data. It took a huge effort for LIGO to allow us to dip our toes in the water. Hopefully LISA will let us dive in.

My thanks to NASA LISA Study Scientist Dr. Ira Thorpe for talking to me about how the spacecraft measure their distances and clearing up a misconception I had about the test masses!

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Martin Landau: 1928–2017

Jul. 17th, 2017 04:41 pm
[syndicated profile] badastronomy_feed

Posted by Phil Plait

Well, damnation. Martin Landau has died.

You might know him for his iconic portrayal of Bela Lugosi in the movie Ed Wood —and you should; it earned him an Oscar, deservedly.

But to me he has been and always will be Commander John Koenig, the hot-headed commander of Moonbase Alpha, leader of the 311 men and women there, making the big decisions after the Moon was accidentally blasted out of Earth orbit on September 13, 1999.

Sound silly? Well, yeah, it is. But it was the plot for the TV show Space:1999, and let me tell you, I loved it when I was a kid. Even after all these years (it aired in the US in the late '70s) I still have a deep fondness for it. To this day it has one of the best and coolest spaceships ever, the Eagle Transporter.

I was a tween/young teen at the time the show aired, and my friend John and I never missed an episode. I liked Star Trek at the time (not as much as I do now, though), and Kirk was something of a male role model for me, as was Spock for my science side. But it was Barry Morse as Professor Victor Bergman who was really my fictional science inspiration, and Landau's Koenig I looked up to.

Looking back at it now, with adult eyes and experience, my opinion of the character is different. I understand now that Koenig's character was somewhat erratically written, with anger guiding his decisions as often as concern over the safety of the base or the desire to explore. Of course, we all of us have conflicting motivations sometimes, don't we?

But when I was a kid, I saw him simply as the hero. Oh, how I loved Koenig's take-charge attitude when things got rough, how fiercely he defended his friends and comrades, how quick he was to boil over when they were threatened! I thought he was the epitome of derring-do.

Times were different then, and I am not the person I was when I was 13. Thank heavens! But still, some of that boy is me, parts of him at least. The love of science and science fiction, of story telling in the depths of the Universe … that lives on in me, as does whatever part of that was guided by Koenig and the rest of the Alphans.

You can read about Landau's other achievements and other roles elsewhere. But for me, every year on September 13thI’ll tip my hat toward the Moon. I'll always wish Moonbase Alpha godspeed, and I'll always remember Martin Landau for a role on a show that shaped my love for space forever.

[Hero image credit: Gerry Anderson Productions]

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[syndicated profile] science_at_nasa_feed

Posted by admin

Portal origin nid: 
405299
Published: 
Monday, July 17, 2017 - 10:00
Featured (stick to top of list): 
no
Portal text teaser: 
NASA's Van Allen Probes have observed a new population of space sound waves, called plasmaspheric hiss, which are important in removing high-energy particles from around Earth that can damage satellites.
Science Categories: 
[syndicated profile] badastronomy_feed

Posted by Phil Plait

Our Milky Way galaxy is a collection of gas, dust, dark matter, and a couple of hundred billion stars. Most of those stars orbit the galactic center in a pinwheel-shaped disk about 100,000 light years across and a few thousand light years thick, but there’s also a vast roughly spherical halo of stars around the galaxy stretching out about 100,000 light years, itself.

Most of the stars in the halo are moving around the Milky Way in nice, normal orbits. However, over time a handful have been discovered that are weird: They’re moving too fast.

Milky Way map

A map of the Milky Way based on real observations. Not shown is the huge spheroidal halo of stars and hot gas surrounding the disk of our galaxy. Credit: NASA/JPL-Caltech/R. Hurt (SSC/Caltech)

 

These stellar bullets are screaming around space much faster than the stars around them. Sometimes their velocity is so high that the galaxy’s gravity can’t hold on to them: Their destiny is to escape the galaxy forever.

We call these high-velocity stars. A really big question is actually a pretty a simple one: Where did they come from? There are lots of possible origins for these stars (which I’ll get to in a sec), but a new one has just been found, and I’ll be honest, it surprised me: They are coming from the Large Magellanic Cloud (or LMC), a satellite galaxy of the Milky Way.

That startled me for a lot of reasons, but the biggest is that the LMC is over 150,000 light-years from us, and that’s a long way to travel for a star even at high speed. But a paper just published outlines how it works, and it’s pretty convincing.

The main piece of evidence is that a lot of these high-velocity stars are seen in the constellations of Leo and Sextans. That’s significant, because if you map out the location and orbit of the LMC around the Milky Way, the LMC is headed in that direction (think of it as watching a car zoom past you on a road, and you can see it’s headed toward the east; it might be in front of you at this exact second, but you can extrapolate where it will be in a few minutes). It orbits our galaxy at about 380 kilometers per second, which is really fast, and if you could eject stars from it they would preferentially be found moving in the direction of the LMC itself.

That’s pretty good circumstantial evidence but, to be honest, it’s not enough. Can stars like this, in fact, be ejected from the LMC?

This animation from the journal paper shows nearly two billion years of time as the LMC moves across our sky and the stars ejected from it. The curved path is due to the way the map is shown (like how maps of the Earth can distort the poles); the diustance is listed in kiloparsecs (1 kpc = 3260 light years) and time in millions of years ago. Credit: Boubert et al

 

There are many ways to get stars blowing through space at high speeds. One is if the star starts out in life as part of a binary star, two stars orbiting one another. If they pass really near a black hole, one star can get swallowed by it while the other gets ejected at a pretty substantial clip. We think this happens in our Milky Way when a binary encounters the gigantic black hole at the galaxy’s exact center. Some high-velocity stars seen are consistent with this, but that doesn’t explain the excess seen toward Sextans and Leo. Plus, there’s no evidence the LMC has a big black hole like ours, so that doesn’t really cover the observations.

There are other ways (for example, encounters with other stars in a dense stellar cluster can kick stars pretty hard), but it’s hard to account for both the number and distribution of these stars seen.

contact binary

Artwork depicting a contact binary: two stars orbiting so close together they share a single atmosphere. Credit: ESO/L. Calçada

 

One way seems to fit the bill, though. You start with a binary system, where at least one of the stars is high-mass, more than 8 times the mass of the Sun. Eventually, that star will turn into a red giant, swelling hugely in size. The other star can then draw material off the giant, increasing its own mass. If they are close enough together, they can actually become what’s called a contact binary, a peanut-shaped object which is essentially two stars sharing the same atmosphere! When this happens, the two stars actually can spiral in, getting very close together. As that happens, their orbital speed around each other increases.

Then, catastrophe: The more massive star explodes in a spectacular supernova! If it loses enough mass in the explosion, it no longer has enough gravity to hold the binary together, and the companion star gets flung away at high speed. A-ha! A high-velocity star.

This seems a little unlikely, though. How often does this happen?

Turns out, a lot! The scientists doing the study decided to find out just how common an occurrence this is in the LMC, so they did two things: They used a physical model of how stars form and evolve in the LMC to see how many high-velocity stars you can get this way, and then used a second physical model of the LMC and Milky Way system to see if the gravity of the two galaxies changes the way the stars behave (for example, the gravity of the LMC may slow down the stars ... but the ones shot out ahead of the LMC in its orbit get the galaxy’s velocity added to them, as a ball thrown out a car window gets the car’s speed added to its own).

Runaway star

Artist’s illustration of a runaway star ejected from the LMC (background, using an actual image of the satellite galaxy). Credit: ESO

 

Their model simulated nearly 2 billion years of time, and what they found was pretty cool: Over that time, more than 860,000 stars will have escaped the LMC, making up about 80% of the high-velocity stars seen in the Milky Way’s halo! That shows that it’s extremely plausible that the stars actually seen come from our companion galaxy.

There were other interesting tidbits to come out of this as well. Because these stars were once part of a contact binary, they may have started off lower mass, but gained mass before getting flung out into the Universe. If they wound up with more than about 8 times the Sun’s mass, they, too, would explode over time. The model predicts that about half the stars ejected from the LMC exploded on their way here. These supernovae leave behind either a dense neutron star or a black hole, which means thousands of these objects — tiny, but possessed of super-strong gravity — are blazing past our galaxy even now.

Now, don’t fret: They’re too far away to hurt us in any realistic way, but I do hope some science fiction author hears about this and devises a fun story based on them.

Interestingly, a lot of high-velocity stars are high-mass blue stars (called B stars in the astronomical stellar classification system). That, too, is naturally explained by them once being in a contact binary, where they gained enough mass to fall into this category.

So, how do we prove this? High-velocity stars can be found in a number of ways. In general, it’s through their spectrum; when you break the light up from a star into thousands of narrowly sliced colors, you can learn a lot about them, including their speed. But that’s a hard measurement to make on a large scale.

You can also take images of lots of stars in the sky, wait a few years, then do it again. Stars moving rapidly enough in space will move noticeably in such a survey (if the observations are accurate enough). And there is such a survey: Gaia, which is mapping a billion stars in the Milky Way. Over the course of its multi-year mission it may find quite a few of these runaway stars.

So, is this idea of cannonball stars from the Large Magellanic Cloud correct? Maybe. I do like it, and it explains a lot. The good news is it’s testable, making predictions about the numbers, locations and types of stars we should expect to see in the Gaia survey. Time will tell, and we won’t have to wait too long, since the survey results needed for this will be released over the next few years.

Every time I think I’ve heard everything about astronomy, something new comes along. Alien invader stars from another galaxy! Science is just so much fun.

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Unwanted Blogging Vacation

Jul. 17th, 2017 09:56 am
[syndicated profile] charlie_stross_diary_feed

I am taking an (unasked-for) vacation from blogging to attend the bed of a close, elderly, family member who is dying. This is not unexpected, but death doesn't generally happen on a schedule and I've no way of knowing whether it is hours or days away at this point: so life for the rest of us is, perforce, on hold—and so are my blog updates.

(There may be some appearances, probably unheralded, by guest bloggers over the weeks ahead. Watch this space.)

ConGregate 4/DeepSouthCon 55 or Bust!

Jul. 14th, 2017 09:23 am
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[personal profile] eldritchhobbit

I’m looking forward to being a literary/scholarly guest this weekend at ConGregate 4/DeepSouthCon 55!

I’ll be on several panels and wearing my moderator hat. Here is my schedule.

image

JULY 14 • FRIDAY

5:00pm – 5:50pm: Writing in Multiple Tie-In Universes 

Moderator: Amy H. Sturgis

Guests: Alexandra Christian, Barbara Hambly, Melissa McArthur, Richard C.

Our panelists have written official novels for Star Wars, Star Trek, and Beauty and the Beast, as well as Sherlock Holmes pastiches. Given that they also write a lot of other fiction, the panelists discuss the differences between writing original fiction and writing for pre-existing franchises/worlds.

6:00pm – 6:50pm: Writing Sherlock Holmes and Other Icons

Moderator: Amy H. Sturgis

Guests: Nicole Givens Kurtz, Misty Massey, Melissa McArthur, J. Matthew Saunders

Sherlock Holmes, James Bond, Superheroes… What are the challenges with writing these iconic characters? And if you change them, how do you make sure to capture their essence? When writing an iconic character, how do you determine what makes them iconic?  Is it Sherlock Holmes being a detective, or Bond working for MI-6?  What happens if Holmes is a demon, or Bond is set in a fantasy world?

JULY 15 • SATURDAY

9:30am – 10:20am: Mixing Historical Research with Genre Fiction 

Moderator: Amy H. Sturgis

Guests: Barbara Hambly, Kim Headlee, Tally Johnson, Linda Robertson

Given that historical fiction itself is a demanding genre requiring a lot of effort if one wants to do it right, our panelists discuss the challenges they’ve faced and choices they’ve made in blending historical work with the fantasy and mystery genres.

1:00pm – 1:50pm: Writing from Different Perspectives

Moderator: Amy H. Sturgis

Guests: Samantha Dunaway Bryant, Barbara Hambly, Larry N. Martin, Michael G. Williams

Authors often try to write about protagonists who are different from themselves. Our panelists discuss why they feel it is important to capture these characters’ perspectives; the challenges faced in trying to be authentic, respectful, and sensitive in their portrayal; and what they think about current debates and controversies about the importance of diversity, authenticity, and representation in fiction.

Not Just Me - Documentary review

Jul. 16th, 2017 04:31 pm
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[personal profile] rattfan
I just saw a local documentary, Not Just Me, produced by Jonathan Messer and featuring four local transmen.  I’ve met David in person a few times and at least recognise the names and photos of the other guys.  This film was part of the Revelation Perth Film Festival at Luna Leederville.

It was great to hear local transmen talk about being trans, often echoing my own thoughts and experiences, and to see the local scenery as the cameras followed them around Perth.  All up, the film had a sense of hope and optimism about the future, that one day it will be accepted that people come in more varieties than was originally supposed.  For needle phobics, here’s a warning that there are also several scenes involving a very large needle being applied to various backsides.

The quality of the segments featuring each transman varied drastically, I presume based on the person’s availability for filming, because one covered experiences of a year, two for six and four months and one a single day.  Now, only hours after the viewing, I’m left with pretty clear images from the two best presented, Simon and David, and only vague memories of Max and Logan’s sections.  Logan’s sections were self-shot with a very jerky camera.  I’m one of the people who can’t tolerate watching jerky camera footage without feeling sick, so I had to stop watching whenever it switched to these segments.  The scene of Logan talking with a friend was outside and very noisy.  While it began with dialogue captions, this didn’t continue and there was quite a bit I couldn’t catch.  This could have been remedied with a bit more captioning and also guidance from the producer.

All the guys depicted were twenty-somethings, which made me groan a bit, because that’s a constant problem I have as an “older” transman, that everyone sees this as something young people do.  Older folk are invisible.  This meant that quite a bit of what they were talking about was not something I could really relate to, so I would have liked to see a bit more diversity.  The director talked (in an earlier interview) about being surprised that there was a “strong culture” of transmen in Perth and that it had taken him a long time to acquire subjects because of “gatekeepers.”  I’m honestly not sure what that means.  I can only say I didn’t have a problem finding and meeting trans people.

Still, the fact that it was made at all is definitely a plus and hopefully we’ll see more on this subject down the track.  Maybe a mini-series?

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[personal profile] snakypoet
1. Sensational or Underwhelming? 

I am actually posting excerpts of the memoir (first draft!) on a blog, not here but out in the wider blogosphere, with my own name on it and all. And I post links to the episodes on facebook and Google+. It seems I am a bit of a storyteller after all – just not in fiction. At any rate, people say they enjoy reading it and urge me to keep going.

The last episode got very, very personal about my sex life. My sex life in my twenties, that is; there's not a lot to disclose now. But back then there was dysfunction closely followed by adultery. I hadn't thought to disclose so much detail as I did. I found that I needed to in order to tell the real story.  I was proud of myself when I'd got it all down, for the way I dealt with it and the fact that I told so much of the unpalatable truth.

What surprises me is that there has been so little comment on facebook. I finally struck them dumb, eh? 
 

2. Self Image

 I have spent all my life thinking I was ugly; only attractive to those men who could see past the physical. In the course of writing the memoir, remembering back, I realise that lots of men thought I was attractive enough that they wanted to go out with me – more than I am including in the memoir, because I am only including the men who were important in my life. And actually, there were a fair few of them too. And they were all good-looking fellows themselves. It finally dawns on me that I simply couldn't have been as ugly as I thought.

Why did I think so? I believe I know.

When I was very young – maybe five – I went to stay with my aunty and uncle and cousins in another town, for a holiday. My aunty found my long hair difficult to manage. Dad, who was a travelling salesman, called in when he was down that way. My aunty asked him if she could cut my hair, and he gave consent. It was blonde, and had been nearly down to my waist. She cut it straight across, neck length. When it was time to go back home, Dad came and fetched me. We arrived back at our own place, and my Mum came rushing out to meet us. She saw me, stopped in her tracks, and wailed at him, 'Oh Rob, her hair – it was her One Beauty!' (I swear I heard those capital letters.) 

I think, now, it said a lot more about her than me. But I was five.

Perhaps it says even more about a society where there was one standard of beauty, and if you were female it mattered very much. But it was more than 70 years ago.

And I'm still buying it, one way or another! All the same, it's good to finally realise I can't have been all that ugly after all.
 

The Great. Red. Spot.

Jul. 14th, 2017 12:00 am
[syndicated profile] badastronomy_feed

Posted by Phil Plait

On July 11, 2017, at 00:55 UTC, the armored tank of a space probe Juno reached perijove, the closest point in its orbit over the mighty planet Jupiter. Screaming above the cloud tops at over 200,000 kilometers per hour — fast enough to cross the continental Unites States in a minute and a half — it took eleven minutes and 33 seconds to reach the Great Red Spot.

Looking down from its height of a mere 9000 km above the clouds, what it saw was ... glorious.

 

Jupiter from Juno
Are you kidding me? Wow. Jupiter, the Great Red Spot, and the jaw-dropping beauty of atmospheric turbulence on a giant planet. Credit: NASA / SwRI / MSSS / Gerald Eichstädt / Seán Doran

[Are you kidding me? Wow. Jupiter, the Great Red Spot and the jaw-dropping beauty of atmospheric turbulence on a giant planet. And this is a smaller version; here's the huge one (7800 x 3500 pixels!). Credit: NASA / SwRI / MSSS / Gerald Eichstädt / Seán Doran]

The Great Red Spot is a storm, a vast, sprawling magnificent anti-cyclone, a high-pressure vortex that’s been swirling in Jupiter’s clouds for centuries. I wrote quite a bit about it last week in preparation for the Juno images, so please read that to find out more, and watch my episode of Crash Course Astronomy on Jupiter for more about the massive planet and its ridiculously huge storm systems.

But I feel the need to give you a sense of scale here. Jupiter and Earth are both planets, but could scarcely be placed under that name together when you compare them. Jupiter is over 143,000 km across its equator, 11 times wider than Earth. 1300 Earths could fit inside it with room to spare. It has over 300 times the mass of our planet, too. All the other planets in the solar system could fit inside it.

Jupiter Great Red Spot
Jupiter's Great Red Spot, seen by the Juno spacecraft on July 11, 2017. Credit: NASA/JPL-Caltech/SwRI/MSSS/Gerald Eichstadt

[Jupiter's Great Red Spot, seen by the Juno spacecraft on July 11, 2017. Credit: NASA/JPL-Caltech/SwRI/MSSS/Gerald Eichstadt]

The Great Red Spot is a storm befitting such a huge world. It’s currently 16,400 kilometers across — nearly 1.3 times wider than our entire planet Earth! It’s actually shrinking, and no one really knows why. It’s only about a third as wide as it was a few decades ago. Perhaps Juno data will help planetary scientists figure that out.

The detail is phenomenal. You can see how the rotation of the spot creates turbulence and smaller vortices as the atmospheric gas inside the spot rubs up against the atmosphere around it. Something I didn’t expect is that the level of resolution allows subtle details to catch the eye, like shadows of some clouds indicating their higher altitude! That’s astonishing; previous images of the spot tend to make it look flat, two-dimensional, but now we’re starting to see vertical information. I can imagine atmospheric scientists drooling over this data, allowing them to make more maps of the structure of Jupiter’s fantastically complicated atmosphere.

Jupiter Little Red Spot
The Little Red Spot, about half the size as it's big sibling. Credit: NASA / SwRI / MSSS / Gerald Eichstädt / Seán Doran

[Credit: NASA / SwRI / MSSS / Gerald Eichstädt / Seán Doran]

The Great Red Spot wasn’t the only thing Juno saw up close. It also passed over the Little Red Spot, a similar storm but only (heh, “only”) half the size. You can see some vertical detail in this shot as well!

Jupiter Little Red Spot
Jupiter's Little Red Spot, seen in more detail. Credit: NASA/JPL-Caltech/SwRI/MSSS/Damian Peach

[Credit: NASA/JPL-Caltech/SwRI/MSSS/Damian Peach]

The last time any probe was able to see the Great Red Spot in detail was Galileo, which orbited Jupiter for nearly eight years, starting in 1995, before it burned up in the planet’s atmosphere in 2003. The Voyager 1 and 2 probes passed the planet in March and July of 1979 before that.

Jupiter Great Red Spot
Voyager 2 saw the Red Spot in 1979. Credit: NASA/JPL/Kevin M. Gill

[Voyager 2 saw the Red Spot in 1979. Credit: NASA/JPL/Kevin M. Gill]

Juno’s primary mission actually isn’t to image the planet, though! It’s designed to use various detectors to learn more about Jupiter’s interior, composition and possible formation. Those instruments are buried deep inside the spacecraft, protected against the brutal radiation environment near Jupiter. The JunoCam was built specifically as a public outreach effort. I love this: There’s no way NASA was going to send a spacecraft to Jupiter, let it drop down so close to the cloud tops and not send pictures back! So the camera was built by Malin Space Science Systems as an effort to get the public excited about Jupiter and space exploration.

It’s working! The images are public as soon as they get back from Juno, and a lot of very dedicated and talented folks immediately tackle them, processing them and creating the incredible art you can see for yourself at the Juno image gallery.

Even though this is the seventh perijove dive, it’s the first time we’ve seen the Great Red Spot up close. Jupiter is big, and the Spot is small in comparison. Juno is on a polar orbit, so it passes over Jupiter’s north pole, moving southward over the clouds. It gets so low that it can only see part of the planet at any one time, with its view widening as it rises higher. Because of that we see a long “vertical” swath of Jupiter cutting across all latitudes but only at a narrow range of longitudes. If that doesn’t include the spot, we miss it.

But this time the stars aligned, so to speak. I’ll note that Juno is not on the orbit now it was intended to have. A pair of stuck valves prevented an engine burn that would have dropped the spacecraft into a lower orbit, circling the planet every two weeks. Engineers opted to not make a risky burn that might put Juno in the wrong orbit, and instead left it in the two-month-long, far higher and more elliptical orbit. It can still do the science needed in this orbit.

The camera is by necessity on the outside of the spacecraft, and getting damaged by that radiation every time Juno approaches Jupiter on its 53-day elliptical path. I haven’t seen any news on how well the camera is holding up, but it may only last one more perijove pass. Perhaps, like so many other machines we send out to visit other worlds, it will exceed expectations. These images are dazzling. Of course, the science from the other instruments will continue, and the mission has already been an astonishing success. But there’s still much to learn, and much to see. Here’s to Juno and its camera surviving for many more orbits, and sending back more amazing images of this stunningly beautiful alien world. 

[Top image: NASA/JPL-Caltech/SwRI/MSSS/Gerald Eichstadt]

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How to Write with a Co-author

Jul. 13th, 2017 04:58 pm
[syndicated profile] sfwa_feed

Posted by Editor

Stewart Baker

by Stewart C Baker

Fiction writing is often presented as an intensely solitary pursuit, but look at the end of a published novel some time and you’ll see the author thank at least a dozen people for their help. And then there’s co-authoring…

There are as many different ways to share authorship of a story as there are combinations of people. Some prefer to split up the tasks of writing, with one author creating an outline that the other drafts from, or vice versa. Others might draft every other scene, or only write a particular character’s sections, and so on.

The benefits of co-authoring are potentially great: Each writer has a chance to learn new habits and strategies, and brainstorming can go much more quickly with two people involved. But, as with any kind of partnership, it’s important to establish early on how the relationship is going to work. Making assumptions about the writing process and your expectations for your co-author can lead to misunderstandings and stress, and has the potential to end friendships and scuttle careers.

Ideally, before you even start writing you and your new co-author will come to an understanding on how you’ll handle all the fine details of writing, submitting, and selling your work. Here are a few of the questions you may wish to consider:

  • What are your writing processes? How do they differ? – Discuss how you usually create stories. Do you outline? How thoroughly? What is your revision process? Experiment until you have a method that works for both of you–or at least one that one of you is willing to try.
  • What are you going to write? – Do you like to write funny stories? Dark ones? Fantasy? Sci-fi? Weird, unclassifiable things? If your co-author isn’t already familiar with your work, talk about the things you usually like to write. If they are, discuss the things you want to write but have never dared to try and the topics or themes you don’t want to touch on. Likewise, it’s important to be on the same page for the scope of your collaboration. Are you writing a single story, a set of linked stories, a novel, or a series?
  • Who will do what? – If you’re working from a draft of a story one of you have already completed, what still needs to be done? If you’re both writing the draft, how will you divide the labor? If you’re outlining your story, will you both be working on the outline or just one of you? Is one of you a better reviser? Better at dialogue? Find your respective strengths and weaknesses and play to them. How will you split the proceeds if you sell the story?
  • What’s your timeline? – Nail down some expectations about when you want the story done and out on submission. Setting up a timeline ahead of time means neither of you has to stress about not living up to your end of the collaboration.
  • What if it fails? – Life happens. Set some guidelines for what to do if one of you can’t finish the story you’re working on, or just realizes that the collaboration isn’t working. This can be particularly troubling if you don’t think about it ahead of time, so sort it out ahead of time and save yourselves the ruffled feathers and awkward unanswered e-mails.

No matter how you and your new co-author answer these questions (and even if you don’t), the discussion will likely teach both of you something new about the craft of writing. In the short term, it’s likely to make your collaboration more successful, as well.

•••

Stewart C Baker is an academic librarian, speculative fiction writer, and occasional haikuist. His fiction has appeared in Writers of the Future, Nature, Galaxy’s Edge, and Flash Fiction Online, among other places. Stewart was born in England, has lived in South Carolina, Japan, and California (in that order), and currently resides in Oregon with his family­­—although if anyone asks, he’ll usually say he’s from the Internet.

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Posted by ckaiser

Images of Jupiter’s Great Red Spot reveal a tangle of dark, veinous clouds weaving their way through a massive crimson oval.

News Article Type: 
Published: 
Thursday, July 13, 2017 - 10:20
[syndicated profile] badastronomy_feed

Posted by Phil Plait

When I was in graduate school, one of my required classes was an advanced physics class that I struggled through mightily. It was incredibly difficult for me, loaded with unfamiliar equations and concepts. I remember specifically spending days on the mathematics of how heat diffused through a solid, and how a drum head vibrated. The differential equations were...formidable.

But it gave me a taste for how complex the real world can be. If an ideal situation, where you control the parameters, can be so fiendish, what’s it like when the situation is unconstrained and there are a thousand input variables?

That’s what fluid dynamics is like, the study of how things flow. The math there makes what I learned look like kindergarten...and yet, the world performs this experiment everywhere, all the time. Any time you see a creek flow, or a faucet drip, or a tree move in the breeze, you are witnessing the mechanics of fluid dynamics played out.

And that word: “fluid”. We tend to use it interchangeably with “liquid”, but that’s not fair. A fluid is anything that flows, and while a liquid does that, so does a gas. So, “fluid” is a more generic term, and includes things like airflow, atmospheric physics, and even cloud formation and evolution.

That math is so complex, it’s not fully able to be modeled in a computer. But again, the Earth puts these calculations to use all the time, and the result can be staggering beauty.

Witness: Kaibab Elegy, a time-lapse animation of fluids in motion, by photographer Harun Mehmedinović:

 

Oh, my. How lovely. He filmed this in and around the Grand Canyon in Arizona (the Kaibab National Forest borders the canyon to the north and south, hence the video’s title). Usually, the Sun warms the air in the canyon, which then rises. However (as Harun describes it in the video show notes), sometimes cold air flows into the canyon and gets trapped by a layer of warm air above it. This is called an inversion, and can create a cloud layer that forms in the canyon reaching to the top.

But that doesn’t mean it’s motionless! “Dynamics”, after all, implies motion, or at least change. And you can see that over and again in the video, as clouds form and evaporate before your eyes. And while we don’t see this easily when we watch for ourselves, the compression of time in the video makes it very obvious that gas, too, is very much a fluid.

I see this all the time, living east of the Colorado Front Range; we can see clouds forming and dissipating as moist air flows over the mountains and encounters the rising warm air from the plains to the east. While it can make for shaky descents into Denver airport (try to arrive in the morning if you can, before the plains heat up), it also makes for spectacular skies.

Isn’t that science in a nutshell? Complex math, reflected in complex reality, which sometimes affects us personally but always shows us the true beauty underlying the world around us.

[This video was shot as part of the SKYGLOW project, which I highly recommend looking into further. The book Harun put together with fellow photographer Gavin Heffernan is a thing of stunning beauty.]

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[personal profile] mount_oregano
Voting for the Hugo Awards ends on Saturday, July 15, and the winners will be announced at Worldcon 75 on August 11 in Helsinki. Here are my thoughts on the short fiction finalists. Half of the 18 stories were also nominated for Nebulas, which I wrote about in earlier posts. On the whole, I think the nominees present a good overview of short speculative fiction, despite a couple of works that came from over the horizon and aren’t really appropriate for the Hugos.

Novella

“This Census-Taker,” by China Miéville
A young boy living in an eerie post-war small town believes his father killed his mother, but he can’t prove it. Miéville is one of my favorite writers, but I don’t think this is his best work. While the writing is beautiful at the sentence level, the plot moves slowly and ends with loose ends all over the place. Still, there are moments of slow, pure terror to savor.

“Penrick and the Shaman,” by Lois McMaster Bujold
If you like Bujold, you’ll like this. Penrick, a demon-ridden young man (this is nicer than it sounds), must help solve a murder, and things take a strange turn. It’s set in a medieval-like world of five gods who periodically meddle in human affairs. Much of the story explores the world and the people in it, and if it’s not always fascinating, it’s always fun. As you would expect from Bujold, it all unfolds masterfully. That said, I’m not a big Bujold fan, although many people are, and I can’t fault them. This story is just too gentle for my tastes, but I don’t regret the time I spent reading it. While it won’t rank high on my ballot, I will vote for it and won’t mind if it wins.

In fact, all the novella nominees deserve to win. Three were also on the Nebula ballot: “The Ballad of Black Tom,” by Victor LaValle; “The Dream-Quest of Vellitt Boe,” by Kij Johnson; “Every Heart a Doorway,” by Seanan McGuire (which won the Nebula); and “A Taste of Honey,” by Kai Ashante Wilson, which won the Nebula. You can read my comments on those three here.

Novelette

“Touring With the Alien,” by Carolyn Ives Gilman
A newly arrived alien takes a secret bus tour of the United States. During the trip, the driver sorts through her own problems as she bonds with the alien’s caretaker and eventually the alien itself. It’s a quiet story exploring how people at the fringes of alien contact get caught up in the intrigue, and it reaches a satisfying conclusion, but perhaps not as big a twist as the author had hoped.

“Alien Stripper Boned From Behind by the T-Rex,” by Stix Hiscock
This is yet another Sad Puppy nomination meant to dishonor the Hugo Awards, although it reflects more on the Puppies than it does of the author. An alien with three boobs falls for a customer who is sort of a half-human half-Tyrannosaurus rex. They both have exceptionally long tongues and enjoy each other thoroughly. I won’t be voting for it, but it’s not the worst thing on the Hugo ballot.

“The Tomato Thief,” by Ursula Vernon
An old lady living in the desert catches the shapeshifter stealing her tomatoes and decides to help free the unfortunate young woman from a malevolent spirit. And that’s what happens, pretty much as you might expect. The worldbuilding is impressive, but I don’t think the story ever rises above a harmless young adult tale. By “harmless” I mean that it will not make the reader feel any doubt or unease about the world, fear for the safety or integrity of the protagonist, or wonder whether good and evil might be complicated and complex concepts.

“The Art of Space Travel,” by Nina Allan
A woman who works at a hotel copes with a very ill mother who has never said who her father is. Astronauts are coming to the hotel before a mission to Mars, and the woman starts to think about the mystery of her father again. Essentially, this is literary fiction from the future, a fine story that explores human relationships and how both successful and failed space exploration affects the people who never set foot in a rocket.

Other stories that had also been nominated for the Nebula are: “The Jewel and Her Lapidary,” by Fran Wilde, which I didn’t like; and “You’ll Surely Drown If You Stay Here,” by Alyssa Wong, which I did. I commented further on them here.

Short story

“The City Born Great,” by N. K. Jemisin
This surreal story tells about a city that must be born – New York City, to be precise. In this tale of magic, a young man is recruited to sing it through the birthing process. But the city has enemies. While the telling gets heavy-handed in its treatment of homelessness, race, sexual orientation, and the police, the story’s energy keeps building to the end.

“That Game We Played During The War,” by Carrie Vaughn
Two former enemies had bonded over chess. Now the long, exhausting war has given way to uneasy peace. But the people on one side of the war are telepaths, and the other is not. How can they even play a game together? The way they do that shows how peace will be possible. The story stands out for its careful characterizations and its thought into what telepathy does to telepaths and the people whose thoughts they read.

“An Unimaginable Light,” by John C. Wright
In this story, a robot and human have a debate: “I do not wish my thoughts to house any inappropriate content!” “Human emotion and passion must accord with reality; the self deceptions you claim are innate to all thought and must be eschewed. We robots are meant to serve man, not to destroy them.” (Sic.) This kind of debate continues for many pages. Apparently, it’s what the Sad Puppies consider fine writing. They soil themselves with dishonor yet again. The Stix Hiscock story is genuinely better in many respects.

Other short stories on the ballot are “A Fist of Permutations in Lightning and Wildflowers,” by Alyssa Wong, which I love but don’t think is speculative fiction; “Our Talons Can Crush Galaxies,” by Brooke Bolander, which I love and think definitely falls within the genre; and “Seasons of Glass and Iron,” by Amal El-Mohtar, which I think tries too hard to set old fairy tales right – but it won the Nebula. I say a little more about these stories here.

— Sue Burke

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Posted by Phil Plait

Tonight (Wednesday July 12, 2017 at 9/8 Central), the CBS television network premiers the first episode of a new series called Salvation. It’s a drama - part science fiction and part political thriller - about an asteroid discovered on a collision course with Earth. In the show, we have just six months before impact.

I am very pleased to let y’all know that I am the science consultant for the show! It’s my first big-time consultation (I’ve done quite a few before, but usually for one-offs, pilots that never get made, and oh, yeah, a big Hollywood movie where I literally changed one word in the script).

I’ve seen the first episode (you can watch the first 15 minutes here) and I have to say, it’s pretty good. Lots of intrigue and, while I won’t spoil anything, I will say that there are plenty of twists and turns to the plot as story unfolds. It’s been a lot of fun to come up with real (or near-real) solutions to some of the plot points the characters find themselves in. In some cases, I did as best I could to be as realistic and scientifically accurate as possible, but that’s not always the way it works out. As any science consultant will tell you, the story must come first! If the science needs to be bent a little bit to make that happen, well, you can’t be too stiff, or else you’ll break.

I’m OK with that, because without a story you’ve got nothing. Let science add what it can where it can, and don’t sweat it too much if you have to lean more on the fiction side of science fiction.

Salvation CBS
"Salvation" is a new TV series on CBS. Credit: CBS

[Credit: CBS]

With that in mind, and in honor of the Salvation premiere, I thought it would be fun to make a short list of 10 facts, trivia, and misconceptions people have about asteroids and asteroid impacts. Some of these will tie directly into the show, so read this and keep it in mind when you watch the premiere tonight (at 9/8 Central, remember, and check your local listings). How did we do? Leave comments below! And for more info about the show, follow SalvationCBS on Twitter.

So:

Ten Things You (maybe) Don’t Know About Asteroids and Impacts Thereof.

1) Mostly, asteroids spend their time in the Main Belt. Mostly.

Asteroids are chunks of rock, metal, or a mixture of both. There’s no real lower limit to their size — it’s weird to call something the size of a basketball an “asteroid,” but there you go — and the biggest (Ceres and Vesta) are so large they’re called protoplanets.

The vast majority orbit the Sun between the orbits of Mars and Jupiter, far from Earth. But not all of them do. Some share Jupiter’s orbit, for example, and are called Trojan asteroids. Others have looping elliptical orbits, usually yanked into those paths by Jupiter’s mighty gravity.

Vesta
The main belt asteroid Vesta as seen by the Dawn spacecraft. Credit: NASA/JPL-Caltech/UCAL/MPS/DLR/IDA

[The main belt asteroid Vesta as seen by the Dawn spacecraft. Credit: NASA/JPL-Caltech/UCAL/MPS/DLR/IDA]

Others pass close to the Earth. We call those near-Earth asteroids, or NEAs, because sometimes astronomers lack imagination when it comes to etymological coinagement. They come in lots of different groups, generally classified by the semi-major axis of their orbit (the long diameter of an ellipse divided by two, analogous to a circle’s radius).

If the semi-major axis of an asteroid’s orbit is greater than Earth’s distance from the Sun, we call it an Apollo asteroid (named after the asteroid 1862 Apollo, the first of its kind to be found). If the semi-major axis is less than Earth’s distance to the Sun, it’s an Aten asteroid. There are also Amors (which have orbits that keep them at least just outside Earth’s orbit); Atiras (also called Apohele asteroids), which stay well inside Earth’s orbit; and some others. There may even be asteroids that stay inside Mercury’s orbit, called Vulcanoids, but they are currently theoretical; none has been seen.

Which brings us to …

2) An asteroid on an impact course may not come from deep space. It may be a neighbor that’s getting too friendly.

In 2004, an asteroid was discovered, later named Apophis. It was found to be an NEA, on an orbit just about 0.9 Earth years long. It’s an Aten with an orbit that crosses ours, and it was soon discovered that in the year 2029 it will pass so close to Earth it will be under our geosynchronous satellites! It’ll pass no less than 31,000 kilometers over our surface. A close call, but a clean miss.

But there’s more. During that encounter, Earth’s gravity will bend the orbit of Apophis. For a while it wasn’t clear how much. But it was quickly found that if it passed at exactly the right distance (going through a region of space astronomers call a “keyhole”), its orbit would change just enough that seven years later, in 2036, it would impact the Earth!

That caused a lot of concern, obviously. However, more recent observations show conclusively that it will miss the keyhole, and will therefore miss the Earth in 2036 by a substantial margin. Phew! But it was a wake-up call that not all asteroid threats come from far away, and that the keyhole is an important concept in asteroid science.

In Salvation, the asteroid comes from deep space. That’s not impossible, but there are other ones we need to keep our eyes on. But then, how do we find them? Well …

3) Asteroids aren’t usually discovered by people. They’re found in automated surveys.

It used to be that astronomers found asteroids literally by drawing maps by hand, then noting which “stars” moved (the name asteroid, after all, means “star-like”). The first, Ceres, was discovered that way!

Then we invented photography, and asteroids betrayed their existence by their motion around the Sun, leaving little streaks in the images.

Now, though, we have electronic detectors and telescopes that can see wide swaths of the sky. This means we can survey huge chunks of celestial real estate, looking for things that move— and that can be done using software that is much faster than humans.

The vast majority of asteroids are now found this way. The Wide-field Infrared Survey Explorer, or WISE, was a space telescope designed in part to look for asteroids, catching their warm glow in infrared. It found quite a few before the mission ended; it was so successful it was revived and renamed to NEOWISE, for Near-Earth Object WISE.

WISE image of an asteroid
WISE image of the asteroid Santa Claus. Yes, seriously. Credit: NASA/JPL-Caltech/UCLA

[WISE image of the asteroid Santa Claus. Yes, seriously. Credit: NASA/JPL-Caltech/UCLA]

New observatories are coming online now and in the near future that will find tremendous numbers of asteroids, too.

But how many are there? Well …

4) There are billions of asteroids. But the asteroid belt is actually pretty empty.

The main asteroid belt has over a million asteroids bigger than 1 km across, and there are likely more than a billion 100 meters across. Despite that, the main belt is mostly empty space! The total volume of asteroids is less than the Earth’s Moon, and there’s a huge amount of space out there, more than a quintillion square kilometers (and vastly more if you include the volume, not the area, of space available).

It’s also not clear how many NEAs there are. Well over 16,000 are known, and there are probably about 1000 a kilometer or more in size (statistics indicate we’ve found 90% of those already). There are probably a million NEAs bigger than about 40 meters in size out there. We’ve only discovered about 1% of them.

That sounds scary, but we’re looking for them! That’s the first step in preventing them hitting us, after all.

Speaking of which …

5) An asteroid doesn’t have to physically hit the ground to be a big problem.

Sure, you’ve seen movies where some gigantic asteroids slams into the Earth, creating devastation and all kinds of horribleness. But really big asteroids are very rare (the one in Salvation is big enough that very few like it exist). The smaller they are, the more common they are.

Really small ones just burn up in Earth’s atmosphere. We’re hit by about 100 tons of material every day, most smaller than a grain of sand! When that happens, we see a “shooting star,” or more technically a meteor.

If an asteroid is mostly metal, than it can get through the atmosphere and hit the ground hard enough to do real damage if it’s bigger than roughly 20 meters in size or so. The one that carved out Meteor Crater in Arizona was probably 30-50 meters across.

If it’s rock, then it’s more fragile and won’t hit the ground; it’ll disintegrate high up in the atmosphere. But that’s still a problem! Salvation opens (no spoilers) discussing the asteroid that blew up in the air over the Russian city of Chelyabinsk in 2013. That was a real event. The asteroid was rocky, and about 19 meters in diameter. Its power was tied to its kinetic energy, the energy of motion. That depends on the asteroid’s mass and its velocity (actually the velocity squared), and it was moving fast, about 20 kilometers per second. All that energy was released as the asteroid was stopped by Earth’s air, and the result was an explosion equivalent to 500,000 tons of TNT. That’s the same as a small atomic bomb.

That’s why astronomers are so intent on finding these things and preventing them from hitting us. But how do we do that … ?

6) Blowing up an asteroid is NOT the best way to prevent an impact. It may even be the worst.

In the movies, they usually try to blow up the asteroid, creating a cloud of zillions of little rocks that burn up harmlessly in the atmosphere.

But that’s a terrible idea. First of all, that doesn’t help. As I said, the kinetic energy of an asteroid (and thus its impact energy) depends on its mass and velocity. If you blow it up and all the pieces still hit, you haven’t changed the impact energy at all! You’ve just spread it around. For a really big asteroid that doesn’t help, and in fact could make things worse, creating damage over a larger area.

So you might think blowing it up is a better idea if the asteroid is still far away, letting it disperse. But nope. Explosions are hard to get right, and you might create several somewhat smaller pieces still on a collision course. Now you don’t have one problem, you have many. And if you use a nuke, now you have many radioactive problems.

A better idea is to try to nudge it into a path that misses the Earth. There are lots of ways of doing this. Perhaps the best is what’s called a gravity tractor, a small spacecraft that uses its tiny gravity to slowly tug an asteroid into a new orbit (you can find more technical detail here). But that takes a long time. If the clock is running out, you can simply slam a spacecraft into the asteroid, what’s called a kinetic impact, to try to change its velocity enough to miss, us as well (without breaking it up!). Most likely you’d need both a kinetic impactor and a gravity tug to make sure the asteroid misses.

There are lots of other techniques being discussed now. The problem is, none has been tested very well. That’s something I’d actually like to see NASA do, fund a series of missions to try different methods on asteroids to see what works best, and what we need to do to iron the kinks out.

By the way, the B612 Foundation is a group of astronomers, engineers and astronauts dedicated to characterizing the asteroid threat and doing something about it. Many other groups exist as well. Like I said, we take this threat seriously.

One thing we’ll need to know in advance is what the asteroid is made of. They can be full of surprises! For example …

 7) Some asteroids are not much more than piles of rubble.

You probably think of asteroids as being monolithic, literally one big chunk of stuff. But we’ve learned that’s not always the case.

A rocky asteroid orbiting the Sun isn’t alone; there are lots of other asteroids out there. Over billions of years, a typical asteroid will suffer many impacts from those other rocks. If the collision is high-speed, and the intruder big enough, they can both shatter. But a small rock moving relatively slowly will hit the bigger one hard, but not hard enough to disrupt it. Instead, the impact can create cracks in the big one that can run very deep. After lots of such encounters, the asteroid can be so riddled with fissures it’s really nothing more than a pile of rubble held together by its own gravity (and other weak forces).

We’ve actually found several asteroids like this. It’s possible this structure would affect how we try to deflect it, and what happens should one hit Earth, so astronomers are very intently studying these weird objects.

Speaking of weird …

8) Most asteroids aren’t round. Some are shaped like bowling pins!

In movies, asteroids are usually depicted as round. Lots of them are! Especially if they’re big; their gravity can be strong enough to shape them into a sphere. Think of it this way: Imagine a mountain on Earth. If it gets too big the rock inside it isn’t strong enough to support it against gravity, so it collapses. It smooths out. Now imagine a million mountains all over the Earth like that: They all collapse, flattening out. The overall shape that would form is a sphere.

But most asteroids are way too small for their gravity to be strong enough to do that. So they come in all kinds of shapes. Many we’ve seen up close are elongated, like potatoes. Some are even shaped like bowling pins, or like cartoon dog bones! Those may be formed when two small asteroids impact at slow enough speed that they stick together. It’s also possible that over time, various forces can spin an asteroid up, making it rotate faster and faster, until it breaks apart. Then the pieces can reform, creating a dumbbell shape. We see that in many of the comets we’ve visited with spacecraft; comets and asteroids are very similar.

There are other things that can result from this breakup, too. For example …

9) Many asteroids have moons.

Some asteroids have come close enough to Earth recently that astronomers have pinged them with radar. Using sophisticated techniques they can learn a lot about them that way, including their size, how fast they spin and whether they’re alone.

Yup: Just like planets, asteroids can have moons! In fact, something like 16% of NEAs larger than about 200 meters across have small companions. They may form when a bigger asteroid spins up and breaks apart, or undergoes a smallish impact that sends debris into space around it.

asteroid 1998 QE2 and its moon
The asteroid 1998 QE2 imaged by radar shows the motion of its small moon. Credit: NASA/JPL-Caltech/GSSR

[The asteroid 1998 QE2 imaged by radar shows the motion of its small moon. Credit: NASA/JPL-Caltech/GSSR]

An asteroid with a moon provides incredibly useful information: By measuring how long it takes the moon to orbit, the mass of the big asteroid can be found (because the gravity of the asteroid depends on its mass, and it’s that gravity that controls the orbit of the moon). That’s nearly impossible to determine otherwise. That’s one way we know that many asteroids are rubble piles; they have way too little mass for a solid rock their size. They’re full of holes!

But that’s not all they’re full of. In fact …

10) Asteroids are a threat. But they can also be our … salvation.

We almost always hear about asteroids in terms of how harmful they are if they impact Earth. But they’re not all doom and gloom!

Many asteroids have water ice inside them. We’ve detected it in several, and it’s possible quite a few have ice and other useful substances in them.

Useful? Yup. Humans need water to survive, of course, but you can also use electricity (supplied by solar panels, say) to break water molecules up into oxygen and hydrogen. Oxygen is rather useful for breathing, and hydrogen is great as a fuel. So, right there, you have three critical components to inhabiting space!

Scientists are very interested on figuring out whether we can harvest asteroids for materials. If you can mine them and store those materials, they can become space depots, floating way stations for astronauts exploring deep space. Water is very heavy, so launching it into space is difficult and expensive. If it’s already there, you can save a huge amount of effort and money.

They also have metals in them that are useful for building spaceships and structures, too. They could very well be one-stop shopping places for future astronauts. Some private companies have even been started in the hopes of doing this!

I love this idea. It makes space travel far easier, and can provide humanity with the tools and raw materials needed not only to explore space, but to stay there.

If we do nothing, eventually a large enough asteroid will hit us, and could do a lot of damage, destroying a city, collapsing our civilization, or even causing our extinction.

The view from above Saturn
Someday, some human will have this view. Credit: Erik Wernquist, from his magnificent short film "Wanderers".

[Someday, some human will have this view. Credit: Erik Wernquist, from his magnificent short film "Wanderers".]

By learning how to divert asteroids we can prevent this from happening. By tapping into asteroids as a resource we can simultaneously ensure humanity won’t get wiped out by any single cause. If we become a true spacefaring race our future will be long indeed, and will include seeing us setting foot on other planets, hopefully to live there. Permanently.

Extinction, or salvation? The choice is ours.

[Top image credit: Shuttertstock / solarseven]

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Posted by ckaiser

Technology Development: NASA is developing a new instrument to expand the boundaries of astronomy research. A team of scientists and technologists at NASA’s Goddard Space Flight Center (GSFC) is developing the High-Resolution Mid-Infrared Spectrometer (HIRMES)—an innovative instrument that will enable new scientific investigations and important contributions to our understanding of the cosmos. HIRMES' commissioning is anticipated for late 2018 on NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA), a heavily modified Boeing 747SP that carries a 2.5m-diameter infrared telescope. SOFIA flies above ~95% of the Earth’s atmospheric water vapor, allowing astronomers to gain access to wavelengths that are not possible to observe from the ground, even with the most powerful groundbased telescopes. HIRMES applies emerging detector and optical technologies tailored to take maximum advantage of the unique platform provided by SOFIA, covering the 25–122-micron spectral range with resolving powers ranging from 600 to 100,000.

HIRMES will extend proven technologies, striking a balance between pushing the state of the art and providing reliable performance to SOFIA’s growing user community. HIRMES will employ superconducting transition edge sensor (TES)-based bolometers, operating at temperatures of ~0.1 K to provide sensitivity limited only by the intrinsic signal-to-noise ratio imposed by the sky background. These detectors promise an order of magnitude lower noise compared with the heterodyne detectors presently deployed in SOFIA instrumentation, and will decrease observing time by a factor of ~200 on spectral lines of interest. HIRMES detectors will be arrayed in a 16x64-element format to provide low- and medium-resolution spectroscopic observations, including an imaging capability. A separate 8x16-element array optimized for low backgrounds will be used for high-resolving power observations. A multi-stage refrigeration system will provide the ~100mK heat sink needed for background-limited detector performance. Optical dispersion of the light delivered by the telescope will be accomplished via a system of gratings, mirrors, and tunable Fabry-Perot interferometric monochromators.

illustrated diagram
HIRMES on SOFIA will probe the structure and evolution of protoplanetary disks and
increase our ability to model these systems as they evolve to fledgling planetary
systems. (Credit: GSFC HIRMES Instrument Team)

 

Impact: HIRMES’ prime investigation is a detailed study of the processes leading to the formation of planetary systems over a spectral range rich in ionic, atomic, and molecular lines. The HIRMES science program will determine the structure and evolution of protoplanetary disks and will increase our ability to model these systems as they evolve from homogeneous disks to fledgling planetary systems. At the beginning of their lives, stars significantly interact with their environments and the HIRMES program will advance our understanding about the ways these interactions regulate star formation. The HIRMES team will also study the formation processes of massive protostars and the mechanisms that accelerate dust in asymptotic giant branch (AGB) stars. NASA anticipates significant demand within the scientific community for the powerful new capabilities that HIRMES will provide.

Status and Future Plans: The GSFC team developed an instrument concept study in 2016, leading to the competitive selection of HIRMES for development. Work began immediately on development of the instrument, including laboratory evaluation of brassboard subsystems and procurement of limited long-lead hardware items to support an aggressive development schedule. The HIRMES team is working toward a critical design review in FY17, followed by hardware development to enable instrument delivery in late 2018.

Sponsoring Organization: HIRMES development is sponsored by the SMD Astrophysics Division in conjunction with the SOFIA Program Office. Dr. Harvey Moseley is the HIRMES Principal Investigator (PI), with GSFC as the lead NASA Center for HIRMES development. SOFIA is managed by NASA’s Ames Research Center and operated out of NASA’s Armstrong Flight Research Center in Palmdale, California.

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