Bad Astronomy Blog

A Small Asteroid Will Definitely Miss Earth On March 5th. But By How Much?

10 hours 46 min ago

In the “don’t panic” category, the small(ish) asteroid 2013 TX68 will definitely miss the Earth when it swings by our fair world on Mar. 5, 2016.

The orbital mechanics on this is pretty clear; it certainly won’t hit us. The thing is, it’s not clear by how much it’ll miss us, and the range is a bit uncertain: It’ll pass somewhere between 17,000 to 14 million kilometers from Earth.

Yeah. That’s a big gray area. So what gives?

TX68 is a rock roughly 100 meters across, and that’s pretty small as these things go. That means that at any respectable distance from Earth it’s essentially invisible; too faint to detect. We can only see it when it gets close enough to Earth to be visible to telescopes, and that window of opportunity doesn’t last long.

It was discovered in October 2013 when it was about 1.5 million kilometers away (three times farther than the Moon), and was only observed over a three-day span before it became too difficult to see. That makes getting an accurate orbit for TX68 really hard. I’ve written about this before:

Think of it this way. Imagine you’re an outfielder in a baseball game. You see the pitcher throw the ball, and the batter swings. It’s a hit! But one-tenth of a second after the batter makes contact, you close your eyes. Now, based on the fraction of a second you saw the ball move, can you catch it? I would be willing to bet a  lot of money you won’t. You weren’t able to watch the ball long enough to get a good fix on its direction, its speed, its position. It could land next to you, or it could fall 40 meters away, or it could be knocked right out of the park. The only way to catch it would be to keep your eyes on it, observe it as long as possible until you can be completely sure of where its headed.

That’s the problem; with only three days of observations of TX68 back in 2013, it’s impossible to predict exactly where it will be when it passes the Earth in March. What you get is a fuzzy prediction that puts it near the Earth, with a range of likely distances based on that. The closest it can get is 17,000 km, but it could pass us 14 million km away.

From a position of “Ohmygod is this thing gonna hit us?” we’re pretty safe. From an astronomer’s position of “Hey I want to observe this thing for myself and help nail down its orbit” it’s frustrating. That uncertainty means we’re not even really sure where it’ll be in the sky at a given time. Our best bet is to use wide-field telescopes, scan the most likely areas it’ll appear, and hope for the best.

And I hope the best is what we get. TX68 is a near-Earth asteroid, passing pretty close to us; it could impact us in the future. As it stands right now the odds are extremely low for the next few decades… but that’s based on the orbit as we know it now. After this pass we should increase our understanding of the orbit substantially.

To be honest, that won’t be easy. If it does pass only a few tens of thousands of kilometers away, the Earth’s gravity will change its orbit (it also may pass within 20,000 km of the Moon, further altering the asteroid’s orbit), making it even harder to predict its future position.

All of this underscores our need to have more eyes on the sky. An impact from a TX68-sized asteroid is pretty rare; statistically speaking it only happens every ten thousand years or so. But smaller rocks are more common, and impacts from them more frequent; the Chelyabinsk event of 2013 was caused by a rock a mere 19 meters across and impacts from something that size happen on the every-few-decades timescale. The more ‘scopes we have scanning the skies, the more likely we’ll be able to see such a rock in advance, and the more time we’ll have to do something about it… assuming we get around to figuring out just what to do.

Categories: Astronomy Headlines

Music of the Spheres

Sun, 02/07/2016 - 06:30

When space and astronomy based time-lapse animations started becoming popular a couple of years ago, all it took was some cool imagery to get noticed. But over time we’ve seen a lot of such animations, and (unless the footage is really dramatic or unusual) it’s tougher to draw attention now.

Nicolaus Wegner — who has created quite a few stunning storm time-lapse animations I’ve featured on the blog — knows this. He wanted to make a video highlighting “… how important and amazing our Earth is.” Using footage from various space probes and astronauts on the ISS, he put together this short video. “Final Frontier”, to do so.

Mind you, we’ve seen a lot of this footage before. What makes this special? Hint: Listen to the music as the images roll by.

The music Wegner used is called “Falling Short” by Danny Odon. It’s electronica, and as the video starts (with images of the Sun, Pluto, the comet 67/P Churyumov-Gerasimenko, and more) it’s eerie, driving. But when the video cuts to shots of Earth it becomes more melodic, fluid, and soothing.

Then, building a bit in tension, it cuts to very odd and disturbing tones as the video shows the weird moons of Saturn in motion seen by the Cassini mission, reminding us that our solar system is a bizarre place once we leave the confines of Earth. It’s a clever bit of story telling, allowing the music to set the tone and manifest the theme without having to overtly state it.

I’ve said this many times, but the choice of music is critical to short videos like these. I’m a soundtrack geek, and when I watch movies, TV, and short films like this one I find myself paying as much attention to the music as the footage. Working together, they inform our brain far more than either can on their own.

Categories: Astronomy Headlines

Edgar Mitchell, 1930 – 2016

Sat, 02/06/2016 - 06:15

I'm very saddened to write that we’ve lost another Moon walker: His family just announced that Edgar Mitchell, Apollo 14 astronaut, died on Thursday (Feb. 4, 2016).

By coincidence, he died on the 45th anniversary of his mission, just one day short of the anniversary of the date he landed on the Moon.

All twelve men who walked on the Moon are heroes. They risked their lives to go where no human had gone before, and our planet — our species — is the better for it. What Mitchell and his fellow astronauts did will forever be a part of history. Each mission was an amazing story, and I urge you to read about Apollo 14 (and also read Andy Chaikin’s fantastic A Man on the Moon, too, for insight into the Apollo program and the people involved).

To be fair, too, Mitchell will also be known for some of his more unconventional beliefs. For example, he was a vocal advocate in the UFO community. He believed aliens were visiting Earth, and that there’s a government conspiracy to cover it up. As you can imagine, he and I didn’t see eye-to-eye on that.

However, that doesn’t mean he believed in all conspiracies. I met Mitchell a few years ago at a gathering of space enthusiasts, and chatted with him briefly about people who believe the Apollo Moon landings were faked (I haven’t talked about it in a while, but a little while ago I wrote extensively on the subject). I asked him if he had ever run into Bart Sibrel, one of the biggest mouthpieces for that silly idea (yes, the guy Buzz Aldrin punched).

Mitchell laughed, and said that Sibrel came to his house on false pretenses (a Sibrel forte) and once inside started making accusations of fakery, demanding Mitchell swear on a Bible that he did in fact walk on the Moon. Mitchell told me he did swear on the Bible, and then said he immediately — and literally — kicked Sibrel out of his house.

That still makes me smile.

And a lot of people give Mitchell grief for conducting ESP experiments while on Apollo 14. That sort of thing was pretty popular in the late 60s and early 70s, and a lot of the experiments going on weren’t well conducted. Mind you, I don’t think such extrasensory powers exist; the evidence is at best very shaky and the cases that get popular tend to be fraudulent. However, I also have no problems in general testing such claims, and having three men out in space, tens or hundreds of thousands of kilometers from Earth does make for a decent control setting. I don’t really blame him for trying, even if he may have been biased toward believing in it.

My point? People are complicated. If there’s a bigger testament to the reality of the fields of science, mathematics, and engineering than walking on the Moon, then I’m unaware of it. But that didn’t prevent him from still having beliefs that were at odds with some the principles of those same fields. But in that sense he was no different than the rest of us. We all have them, to one degree or another.

I think it’s OK to remember that, especially when talking about the life and career of someone like Mitchell. It highlights the complex nature of how we think, of what makes us who we are. Of how it makes us human. Reflecting on ourselves is a natural response to hearing of someone’s death, and if his legacy is in part to remind us of what it means to be human, then that’s not such a bad one.

And one final note. Mitchell was the sixth human to step foot on the Moon. With his death, there are now only seven people alive who have left bootprints there. I hope that we see humans walking on the Moon once again, and soon; soon enough that the Apollo astronauts themselves can witness it. We owe them that much.

Categories: Astronomy Headlines

Gigantic Space Telescope’s Main Mirror Now Complete

Fri, 02/05/2016 - 06:30

Well, this is pretty cool news: The main mirror for the James Webb Space Telescope is now fully assembled!

OK, first, JWST is the successor* to Hubble, an observatory optimized for viewing the Universe in infrared wavelengths, outside what our human eyes can see. This will make JWST very sensitive to distant galaxies, low-mass stars, planets orbiting other stars, and about a zillion other very interesting astronomical objects.

And second, JWST’s mirror isn’t like other telescope’s, where you have a giant solid piece of glass. Instead, JWST’s mirror — which is 6.5 meters across! — is made up of an array of 18 hexagonal segments, each about 1.3 meters wide.

There are lots of advantages to this design; each mirror can be made much lighter weight than 1/18th of a big mirror, and mass matters when you’re launching a ‘scope into space. The mirrors are made of beryllium, which is very lightweight, so each segment has a mass of only 20 kilograms (45 pounds)!

Also, the entire assembly folds up like origami, allowing the completed mirror to fit inside the payload space of an Ariane 5 rocket. Finally, each mirror has its own independent actuators on the backside, allowing each segment to be individually adjusted to ensure perfect focus for the ‘scope.

The assembly of the main mirror is a big milestone for the observatory. It’s fantastically complex, and nothing quite like this has ever been flown into space before.

Oh, another thing about the mirrors: They’re coated with gold. Gold reflects infrared light very well (most glasses don’t), so it makes a great coating. Each mirror has a layer just a tenth of a micron thick; that’s 0.001 times as thick as a human hair! Even though it’s covering about 25 square meters in total, the layering is so thin that the total mass of gold used isn’t much, about 50 grams. The gold used is ultra pure and not cheap, but the kind of pure gold you can get on the market runs about $40/gram right now, so at that price JWST has only about two grand worth on it. That’s probably the least expensive part of the entire mission.

A lot of the work done on the mirror segments was performed at Ball Aerospace, just down the road from me in Boulder, Colorado. When the assembly was finished in 2012, they had a small press event, and I was able to attend. The highlight of that day was seeing one of the flight mirrors (that is, one of the actual segments that will fly into space as part of JWST’s main mirror) from just a couple of meters away! It was in a clean room, and I got a shot of it through a door:

Yes, that’s me reflected in the hexagonal mirror. That was a pretty cool day.

The final assembly of the mirror segments on to the "back plane" was accomplished this week at NASA's Goddard Space Flight Center in Maryland. The entire process took several weeks.

I’ve had varying opinions on JWST over the years; it will be a magnificent and ambitious space telescope, and will revolutionize infrared astronomy in much the same way Hubble did for visible (and ultraviolet) light. But it’s also had massive cost overruns and is far, far behind its original schedule, and that’s bruised NASA’s overall budget (and politics) for other astronomical missions over the years.

But while that still aches a bit for me, that doesn’t affect what this mission will hopefully accomplish: Give us the clearest, deepest, and best view of the Universe we’ve ever had at these wavelengths.

Congratulations to everyone involved in getting this important step done! And keep up the good work; there’s still a ways to go before the scheduled October 2018 launch.

* Over the years I’ve seen a lot of people refer to JWST as the “replacement” for Hubble. That’s just not correct; for one thing they look at different parts of the electromagnetic spectrum, so JWST can’t replace Hubble in that regard. Plus, if all goes well, Hubble will still be in use when JWST gets to work, so we’ll have both telescopes to peer into the Universe. One of the things I’m most excited about is having both of them look at some of the same objects at the same time; many phenomena are far easier to understand once you get different eyes looking at them.

Categories: Astronomy Headlines

Is This the Biggest Spiral Galaxy in the Universe?

Thu, 02/04/2016 - 06:15

Nature does love spirals.

From the cream floating in your coffee cup to hurricanes to galaxies themselves, spirals form on a vast range of scales. They may be for different reasons (coffee and hurricanes have faster rotation in the center, winding up the arms, whereas galaxies form spirals from a more subtle and complex effect that acts like an interstellar traffic jam), but when you have stuff that spins, spirals can arise naturally.

But how big a spiral can you get? Our Milky Way galaxy is pretty beefy, one of the bigger spiral galaxies in the Universe. It’s roughly 100,000 light years across, or a quintillion kilometers. That’s a lot of kilometers.

Don’t go bragging to your friends just yet though. It turns out spirals can get bigger. Way, way bigger.

The galaxy pictured at the top of this post is called Malin 1. It’s faint; so dim it was only discovered in 1986, and was the first discovered in a class of galaxies called low-surface brightness spiral galaxies. Most spirals are pretty bright and easy to see, but LSBs are much fainter. Despite that, they can grow to huge sizes.

I’ve known about Malin 1 for a while, but it hadn’t really registered with me one way or another. That changed instantly when I saw a new paper about it which was featured on the American Astronomical Society’s Nova site, where notable discoveries are highlighted.

I saw the photo of it and nodded in admiration; it’s a very pretty and interesting spiral. But then I saw the distance, and my brain did a double take. Malin 1 is 1.2 billion light years away.

“Wait,” my brain said, shaking itself. “What? That can’t be right!”

But it is. 1.2 billion light years is a tremendous distance. If it’s that far, and that big in the image, it must be huge. Freaking huge.

Yeah. My brain was right. Malin 1 is well over a half million light years across.

Holy Haleakala. That’s ridiculous. It’s hard to explain how big that is. The Milky Way is titanic, and Malin 1 dwarfs it.

Here, this’ll help. I added a drawing of the Milky Way into the Malin 1 image, roughly to scale. Malin 1 is easily five times wider than the Milky Way.

That’s very interesting indeed. How do you get galaxies that big? We know most (if not all) galaxies grow by eating smaller galaxies (literally the smaller galaxy gets ripped apart by the bigger galaxy’s gravity, its gas and stars ingested by the bigger beast), or merging with galaxies of comparable size. We can see the leftover remnants of smaller galaxies the Milky Way has eaten, and in a few billion years we’ll double in mass when the Andromeda Galaxy collides with us.

But it’s not clear how Malin 1 (or other low surface-brightness galaxies like it but somewhat smaller) grew to such enormous proportions. And why isn’t it brighter, like other, smaller spirals? Digging through some papers on Malin 1 I found that it’s not forming stars as rapidly as the Milky Way; stars are born in the Milky Way at twice or more the rate they are in Malin 1. That may be why it’s dimmer (fewer massive stars born means less light coming from the galaxy). But I don’t think anyone really knows.

I’m usually not all that impressed by cosmic records; finding the most distant this or the biggest that. I’m more excited when that record tells us something. The most distant galaxy tells us how young the Universe was when the first galaxies formed, for example.

In the case of Malin 1, it’s telling us how physics operates on the biggest scales. Spirals can form in galaxies five times bigger than ours… and somehow that may also be correlated with the galaxy being dim.

There are also some peculiar features in Malin 1; you can see a long straight feature pointing away from it at about the 11:00 position (another one, on the opposite side of the galaxy center, is likely a background galaxy coincidentally superposed). This feature may be a long stream of gas and stars pulled out from Malin 1 by a close encounter with another galaxy off the edge of the picture. These long features were invisible in previous images, but can be seen here thanks to the power of the giant Magellan 6.5 meter telescope, which took the image (and some sophisticated techniques used to enhance the image as well). A Hubble image taken a few years earlier only hinted at the far-flung spiral arms, showing you just how important the telescope size can be (Hubble’s mirror is 2.4 meters across).

It’s not surprising to me that our census of the Universe is still incomplete; there are lots of things so far away — or close by and so dim — they’re invisible to our prying eyes. But it’s still something of a shock when we find objects this flippin’ huge that have managed to evade us for so long.

It’s a sobering lesson. The Universe is almost incomprehensibly vast, and still holds many of its secrets dear. What else have we missed?

Categories: Astronomy Headlines

Science Ranch 2016

Wed, 02/03/2016 - 09:13

If you love science (and yes, you do), meeting other people who also love science, and being outdoors in a spectacular setting, then do I have something for you.

My wife and I run a company called Science Getaways, where we take fun vacations and make them better by adding SCIENCE. Today we’re announcing our next getaway: Sylvan Dale Guest Ranch in Loveland, Colorado.

Science Ranch 2016, as we’re calling it, will be from Sunday, July 31, to Saturday, Aug. 6. The Sylvan Dale Guest Ranch is located at the foothills of the Rocky Mountains, in a really lovely valley where the Big Thompson River comes out of the mountains. Some of the rocks in the cliff walls visible from the ranch are well over a billion years old! The geography and wildlife of the area are just breathtaking.

Speaking of which, we’ll have three guest scientists joining us: Dr. Dave Armstrong, an ecologist who co-owns the ranch and knows the area extremely well; Dr. Holly Brunkal, a Colorado geologist and a perennial Getaways favorite (this will be the fourth time she’s joined us); and my old friend Dr. Dan Durda, an expert on asteroids and suborbital spaceflight. All three will give talks, and Dave and Holly will lead us on hikes to see the biology and the geology of the region up close.

And, as usual, I’ll be giving a talk, and I’ll have my solar telescope for viewing activity on the Sun as well as my trusty 20 cm Celestron telescope to take advantage of the dark skies there.

You’ll also have the option to take a day trip up to Rocky Mountain National Park (included in the vacation*), one of my favorite places in the world. The views from up there are truly magnificent.

There’s plenty to do at the ranch, too: horseback riding, trap shooting, cookouts, an overnight pack ride, bass fishing, campfires, a heated swimming pool … and an optional river raft ride down the Cache la Poudre River. Or you can simply sit by the Big Thompson River outside your cabin and read a book. We’re very low pressure about activities; do or do not, as you see fit. The lodging rate includes three home-cooked meals per day and all the ranch activities.

This Getaway is also perfect for families; there are activities just for kids, including riding and horse care, and their inquisitive minds will love the hikes and other science activities we’ll be doing.

Sylvan Dale is a second-generation family-owned guest ranch. If you’ve never been to a dude ranch, you’re going to fall in love with this type of vacation. The ranch is very comfortable and homey; it’s not at all like a hotel or resort. It’s a wonderful atmosphere, and we love it. But what makes Science Getaways really special, and what keeps people coming back so frequently, are the folks you’ll spend the week with. Science Ranchers (as we call those who come on our ranch vacations) are some of the friendliest, most fun and interesting people you’ll ever meet. A Science Getaway is not so much like taking a group vacation, it’s more like hanging out with 30 friends in a really cool place.

If this sounds like fun to you, then head over to the Science Getaways page and reserve a spot. We’re keeping attendance lower than usual for this one, and we expect it to sell out. I hope to see lots of BABloggees there!

*Note: Travel to and from the ranch is not included in the price; check the registration page to make sure what is and is not part of the price.

Categories: Astronomy Headlines

Sometimes They Come Back: Giant Gas Cloud on Collision Course With the Milky Way

Wed, 02/03/2016 - 06:30

In 27 million years, you’d better fasten your seat belt: Sometime around then, a gas cloud with enough mass to make 2 million stars like the Sun will come crashing into the Milky Way.

Given the time frame, I’m not too concerned personally over this galactic train wreck. Also, stuff like this happens pretty often in our galaxy, and we’ve made it this far.

Still, it’ll be quite an event, and there’s a funny twist to it: We don’t really know where this cloud came from.

It’s called the Smith Cloud (it was discovered by astronomer Gail Smith in 1963, who was mapping the location of hydrogen gas in the sky), and by all accounts it’s a bruiser: It’s more than 10,000 light-years across; so big that even at its distance of 40,000 light-years (almost halfway across the galaxy!) it appears 30 times wider than the full Moon on the sky.

It’s part of a class of objects called high-velocity clouds; generally pretty big clouds of gas whizzing around outside the body of the Milky Way. Quite a few have been seen, but at 2 million times the mass of the Sun, the Smith Cloud is one of if not the most massive (most are tens of thousands of solar masses). The Milky Way is, overall, a flattish disk, and Smith orbits at a slight (30°) angle to it. Right now it’s about 10,000 light-years below the disk and headed up into it.

Where did this thing come from? There are lots of possibilities: It could be a “dark galaxy,” a clump of gas and dark matter that never formed stars. Or it could be a clot of gas left over from the formation of the Milky Way, orbiting far outside the galaxy, which got disturbed and plunged inward. Or it could be a cloud ejected from the Milky Way itself, blasted out into deep space and now finally heading back.

To find out, astronomers were clever. If the gas cloud were primordial—that is, very very old—it should consist of just hydrogen and helium, the lightest elements. Heavier elements have only been around in the Universe since stars created them, so by looking at the cloud’s ingredients we might be able to eliminate a couple of origin stories.

Using an ultraviolet camera on Hubble (called COS, the Cosmic Origins Spectrograph) they looked for the fingerprint of sulfur in the cloud. That element absorbs a very specific wavelength (color) of UV light (you can learn more about how this works in an episode of Crash Course Astronomy). Helpfully, the cloud’s size betrayed it: It’s so big it happens to cover up several very distant galaxies that emit a lot of UV light. Using those galaxies as light bulbs, the astronomers looked to see if there were any anomalous absorption of that wavelength of UV.

… And there was! Careful analysis indicated that the amount of sulfur in the cloud was pretty high. Kilo for kilo, it has about half the sulfur the Sun itself does (we use the Sun as the standard for such things, because in principle its elemental composition is easy to measure). There’s no way it could have that much sulfur and be left over from the early Universe. So boom, right away we know it isn’t some leftover gas cloud that’s been lurking in the Milky Way’s rural areas.

And we also know it’s not a dark galaxy, either: You need stars to make sulfur, and dark galaxies wouldn’t have any stars.

That means it must be local in origin, a cloud somehow ejected from the disk of the galaxy, where heavier elements are abundant.

We do know of ways that can happen. In several places along the galactic disk are “fountains,” huge eruptions of material blasting out into near-galactic space. These can be generated by a series of exploding stars, or by the fierce winds blown by thousands of young stars all forming at the same time in galactic gas clouds. The vast outflow of material can burst through the galactic plane like a geyser, ejecting a lot of material upward and outward.

And, like a fountain, sometimes that material comes back. The Smith Cloud must have formed that way. It may have started off smaller, but as it plowed through the material located in our galaxy’s halo, it picked up mass. And now it’s ready to deliver all that stuff back to us.

Like I said, lots of high velocity clouds like this are known. What’s interesting is that if you add them all up, they deliver about one solar mass worth of material every year to the galaxy. That is very roughly the same amount the Milky Way uses up every year making stars! So these clouds are like fuel, keeping star formation in the galaxy going. How about that?

Not that this entire mystery is solved. Smith is moving pretty rapidly through space—about 300 kilometers per second, or a million kilometers per hour—and that’s actually faster than the rotation of the galaxy at its location! Most such clouds are actually moving slower than that, so how Smith got its high velocity still isn’t clear.

So what will happen when it does come back? Well, the disk of the galaxy is lousy with gas. When Smith comes barreling in, it may very well collide with that gas. This will generate vast shock waves and collapse the cloud (think two cars in a head-on collision). If it gets dense enough, star formation could be triggered inside it, with thousands of stars being born all at once.

There are multiple sites of star birth in our galaxy, and some are pretty rigorous. This may be just one among them, though I suspect the velocity at which it’s moving will make this somewhat more violent than normal. Two million solar masses moving at a million kilometers per hour …

The galaxy is a surprisingly violent place. In astronomy, though, violence usually means something interesting. It’s how they form, it’s how they die, and it looks like in this case it’s even how they make sure there’s fuel left to generate more. It’s the ultimate recycling program.

Categories: Astronomy Headlines

Mars From a Height

Tue, 02/02/2016 - 09:00

I post a lot of news and pictures of Mars, and when I do it’s usually something taken by a rover on the surface, or it’s a high-resolution image of a small region taken from orbit.

I love these images, and they give us a sense of the kind of detail going on at the surface of Mars. But it can be easy to forget that Mars is actually a world, a huge place with sweeping vistas.

I was reminded of this when I did my usually daily check-in with my friend Emily Lakdawalla’s blog at the Planetary Society. She posted a handful of simply spectacular images of the red planet that were taken by the European Mars Express mission, and processed by Justin Cowart.

The image above shows the Tharsis Shield of Mars, a tremendous bulge in the side of the planet with four volcanoes popping out of it, including the famous Olympus Mons, the largest mountain/volcano in the solar system. I love the overview we get here, including the blue edge of the planet caused by its thin atmosphere.

Cowart’s Flickr page (and his Twitter stream) is a marvel of astronomical imagery, shots from around the solar system, including Saturn and its moons, the comet 67/P Churyumov-Gerasimenko, and more. It’s well worth your time to take a look. There’s nothing wrong with a reminder of how gorgeous our local neighborhood in the Universe is.

Categories: Astronomy Headlines

“Let’s Make Sure That History Never Forgets the Name … Enterprise”

Tue, 02/02/2016 - 06:00

This year marks the 50th anniversary of the most influential science-fiction series of all time: Star Trek. I’m a pretty big fan (Evidence A/B, Evidence 2, ad inifinitum), and I could go on and on about its influence, the characters, the music, and all that. But really, at the center of the show, there is one singular icon: the USS Enterprise.

Oh, that ship. Nothing had ever been seen like that before on TV or in movies — the unusual design and construction, unfettered by the need for gravity or aerodynamics or landing on a planet, yet still sleek and compelling.

For years the original model of the Big E used in the original series (or TOS to those of us in the know) was on display at the Smithsonian’s National Air and Space Museum. But the decades have taken their toll, and the model is currently undergoing reconstruction.

NASM has a great blog, and they just put up a wonderful article talking about the process. If you’re a Trek fan, this is a must-read. The pictures alone are worth it.

As a huge Trek fan myself, I have to tell you about a time I got a piece of the action. Last year, NASM asked me to participate in a fundraiser to help preserve Neil Armstrong’s lunar EVA suit from Apollo 11. I talked with them on the phone about it,and joked that I’d love to be a part of that, but on one condition: I had to be able to see Enterprise myself.

They didn’t hesitate at all. “Of course,” was the reply I got.

“Oh,” I may have replied. I’m not sure, because my memory of that moment is a bit fuzzy. I may have blacked out for a second.

But they were serious. So when the time came … I boldly went.

I went to the NASM Udvar-Hazy Center, where the spacesuit was being conserved. We spent the morning shooting some of the scenes for the promo video (including in a huge room with the Space Shuttle Orbiter Discovery hanging on display), which was fun. Then we moved to a part of the center where some of the real work is done: extremely talented professionals working on preserving and conserving priceless artifacts. We walked into the room where we were going to see Armstrong’s suit … and there she was.

Oh, that ship. Look: Seeing Armstrong’s suit up close (literally even being able to smell it) was a profoundly moving experience, and one I will cherish literally as long as I live. It represents the reality of space travel, of what we did when we had the will.

But that in no way diminishes seeing the Enterprise model, which represents our dream of space travel, of what we hope one day we’ll do. Inspiration comes from many directions, and those dreams play an important role in motivating the reality.

So standing up close to Enterprise, the actual model used in the original series, was thrilling. Thrilling. The ship that started it all, right there in front of me.

It made me think about watching the show when it was in its first reruns, my older brother commenting to me about what was going on as the scenes unfolded (I was pretty young at the time). I had memories of watching Next Generation in grad school, bookending my career there (the first episode aired my first year, and the last one aired seven years later, just before I got my Ph.D.). I flashed back to standing in line at the theater to watch Wrath of Khan, and eventually meeting and even becoming friends with some of those galactic explorers.

Making this encounter even better was meeting Ariel O’Connor, who is a conservator on the model. I wound up chatting with her about all manners of things; she is a font of information about it, with encyclopedic knowledge of its history. More than that, her affection for Enterprise is also readily apparent. Let me assure you, the NCC 1701 is in excellent hands. I’m not sure I’d trust it more if Kirk himself were in charge (after all, he didn’t always bring it home in the best of condition).

Even in its partially disassembled state, it was surreal to stand next to it. For one thing, it’s big: nearly four meters long. The coloring on it is odd, and they’re working on restoring it to its original hues. But even in that room, secured to its support stand, it looked ready to warp away to seek out brave new worlds.

I made a short video showing it; I had to speak softly as the crew was working behind me doing some video of Armstrong’s suit:

At one point, we realized it had to be moved to another spot in the room, or else it would be in our shots of the spacesuit. Several people hovered over it as they wheeled it a few meters over to the corner, and I practically swallowed my heart as they moved it. But these folks really are at the top of their game, and everything went very smoothly.

When we are all done filming, Armstrong’s suit was covered up and wheeled away, and we all headed out the door. As we did we filed right past Enterprise, taking up the corner of the room. I took one last lingering look, knowing how special this day was. It’s not often you get to see some of the greatest and most beautiful icons of space exploration history (both real and imagined) in your lifetime.

It’s not clear when the refit will be done, but at some point the model will be finished, and placed back on display at the museum. And when it does, I must return to this place again.

My sincere thanks to the folks at NASM for letting me use these photos and write about this moment … and of course for giving me this chance to see Enterprise.

Categories: Astronomy Headlines

Climate Change Denier Claims (Heh) That 2015 Wasn’t (Ha) the Hottest Year on Record (HAHAHAHA!)

Mon, 02/01/2016 - 06:15

I (and many others) have shown that the loudest voices in the climate change denial noise machine have long since run out of any real credibility. There are numerous ways to reach that conclusion; for example you can look at how their claims have changed over the years (there’s no warming, there’s not much warming, it’s not warming enough to worry about, warming is good for plants, sure it’s warming but it’ll hurt our economy to do anything about it), you can look at their funding sources (tobacco and fossil fuel interests) whose tactics they deploy, or the fact that they rely on long-debunked claims instead of any real evidence.

But despite this, they do go on. And have no doubt: What they say has real-life consequences—life and death consequences, in fact, for millions of people. More. I’ll get back to that in a moment.

As the denial never seems to cease, I think they’re not only short on credibility, they’re also just short on ways to sell their snake oil. Their ideas get weirder and less believable every time they speak.

That’s the only conclusion I can draw when the claims I see now are so ridiculous, so outrageously, blatantly wrong that it’s hard to believe they can make them with a straight face.

I recently read an op-ed that falls firmly into this category, and it was no surprise at all that it came from James Taylor, from the bizarre world of the Heartland Institute. Remember them? They put up billboards comparing climate scientists to mass murderers, and when people were outraged at the obviously despicable claim (and they hemorrhaged donors because of it), they took the billboards down and, in Orwellian fashion, claimed victory.

So yeah, a view of reality twisted into a Möbius strip is just another day for them.

Taylor’s article was printed in Forbes, and right away, just from the headline, you know you’re about to take a trip into WTFery: “2015 Was Not Even Close to Hottest Year on Record.”

This is one of the wrongiest wrongs to have ever been wronged. Yes, far and away, without question, and where it counts, 2015 was the hottest year on record. Many, many temperature readings confirm that, and it’s not even close; even if you account for El Niño (which tends to make things warmer overall), 2015 blew away the previously hottest year of 2014.

So how can Taylor make this claim? Well, as usual, it’s to cherry-pick a very, very specific set of circumstances: Satellite measurements of a single layer of the atmosphere. As I (and many others) have shown, these satellite measurements are not terribly reliable over the long term, and are nowhere near as accurate as temperatures measured from the ground using thermometers.

Despite this, Taylor states, “By contrast, temperature measurements at the Earth’s surface are less reliable,” which is just flatly wrong. Seriously. It’s just complete fertilizer. If you think I’m being too harsh, then I suggest you read what actual climate scientists have to say about Taylor’s claims, because you’ll see words and phrases like “total fabrication” and “very misleading” and “disingenuous” and “inaccurate” and “wild misrepresentation.” I’m pretty gentle by comparison.

Here’s an analogy for you: Taylor saying satellite measurements show 2015 isn’t the hottest year is like inspecting a horrendous car crash, finding the steering wheel intact, and claiming the accident never happened.

The article is embarrassingly bad, even for an op-ed in Forbes (which has run several such comically wrong articles by Taylor in the past). It’s just so egregiously and obviously and in-your-face wrong, though, that I have to assume it’s aimed only at those who are ideologically predisposed to believe him, in an effort to sow doubt.

And that’s where the consequences come in. Because some of the people ideologically predisposed to use his claims as fodder are other deniers. And some of them have real power, like, say, Ted Cruz. R-Texas.

As a sitting senator (and hopeful GOP presidential candidate), Cruz has access to the best and most accurate science, yet he chooses to ignore it, or worse, actively squash it.

I am no fan of Cruz's, as you might imagine. He is incredibly disingenuous to the point of outright lying, as has been shown many, many times. Cruz distorts the truth so glibly that it’s impossible to know what he truly believes, so it’s possible he really does think the planet isn’t warming up. Or (as seems far more likely) it may be he’s purposely bending his interpretation of reality to match the ideologies of his audience and his benefactors (as I've wondered before, wouldn't it be interesting if senators had to swear to tell the truth during hearings in which they sit? Hmmm.)

But either way, Cruz is dead wrong about global warming. And he uses the same kind of satellite-based argument Taylor does. Cruz still claims warming has flattened since 1998, which has been shown to be so completely, utterly wrong in every way that his making that claim again speaks to his lack of veracity ... but still, Cruz runs the Senate Subcommittee on Space, Science, and Competitiveness, where he trots these claims out as fact.

While it’s almost trivially easy to show that Taylor and Cruz are wrong, they still forge on ahead with as much inertia as global warming itself. In Taylor’s case he’s aided and abetted by such venues as Forbes (and other deniers can find refuge in such places as the Wall Street Journal and the Daily Mail, where, apparently, facts are optional).

Cruz has his own outlets, of course. And since an overwhelming tsunami of scientific evidence shows they’re both wrong, they have to rely on what is sadly a tried-and-not-true technique: barreling on, steamrolling over anyone who speaks against them, and hoping against hope that their own audience won’t call them on it.

Postscript: Speaking of calling them on it, Monday is the Iowa GOP caucus, so it’s important to note that not a single viable Republican presidential candidate has a good grasp on global warming.* A vote for any of them means at least four more years of doing nothing about what has been called by people who would know a threat to our national security. I agree. If someone denies basic science on an issue this important, they do not deserve the office of president.

*Correction, Feb. 1, 2016: This post originally misstated that Iowa's GOP primary is taking place Monday. It is a caucus.

Categories: Astronomy Headlines

SPECTACULAR Photos of a Rocket Re-Entering Over Hawaii!

Sun, 01/31/2016 - 06:00

Around 2:00 a.m. local time on Saturday, Jan. 30, 2016, astrophotographer Steve Cullen was driving home from visiting the summit of Mauna Kea on the Big Island of Hawaii. He stopped at around 11,000 feet to take some panorama shots of the peak… but what he got was much more.

He noticed an orange light heading up into the sky out of the west. It was moving across the sky at about the speed you’d expect from a satellite, but at that time of night no satellite moving at that rate would be lit by the Sun, so it wouldn’t be visible.

Within seconds, though, it became clear what he was seeing: some sort of human-made space debris re-entering Earth’s atmosphere. How?

Because this. Check. This. OUT.

HOLY WOW! What a shot! (Click the photos for bigger, higher-resolution versions on Cullen's Facebook page.) Over the foreground of volcanic rock and more distant clouds (seen from above at that elevation), the debris came streaking toward the east, seeming bursting forth from the constellation of Orion (can you see it behind the trails?).

It turns out this was almost certainly the remains of a Chinese Long March rocket body, predicted to burn up over that area at around that time:

The rocket launched on Sep. 12, 2015, carrying a very secret satellite of some kind. Once the satellite is in orbit the rocket is no longer needed, so it’s allowed to burn up as it falls back to Earth. Doing so over the enormous Pacific Ocean minimizes the risk of debris doing any damage once it’s down.

As the rocket rams through Earth’s air, it compresses the atmospheric gas violently. A compressed gas heats up, and this is so powerful during re-entry that the heat is enough to vaporize the debris. It falls apart, each piece leaving a long trail of ionized metal and gas behind it that can glow for quite some time. They fall together, moving across the sky as a unit, though they separate over time as drag affects each piece separately.

A few minutes later, the pieces started to set in the west.

As the pieces move farther away, perspective makes it look like the trails are converging. This is the same effect that makes rays coming from sun set appear to diverge as they move away from the Sun, and sometimes converge on the other side of the sky.

Finally, once they were gone, all that was left was the bits of glowing particles, literally twisting in the wind dozens of kilometers above the Earth.

I can’t get over how amazing these photos are. I’ve seen lots of cool re-entry photos, but I think these very well might be the very best. 

Mind you, Cullen happened to stop because he wanted to take a few more photos, and did so at just the right time to see this incredible event. Do I even need to say it?

Keep looking up! You never know what you might see.

Categories: Astronomy Headlines

Crash Course Astronomy: Outtakes 5

Sat, 01/30/2016 - 06:00

The final episode of Crash Course Astronomy went up last week, but if you miss it already, we have one final video for you: the fifth outtakes reel, which basically features me trying to pronounce common words as if I have a mouthful of oatmeal.

That bit near the end, where I seem way more upset about messing up thanking people than it calls for? That’s because it took a ridiculous number of takes to get that bit right. I lost count. Maybe 20? More? Mind you, this was literally the very last thing we were recording. Ever. We were wrapping up a long day of being in the studio, I had just finished the content for the final episode, and all I had to do was thank the fantastic folks who put CCA together. And I kept flubbing it. It was really frustrating. Over 46 episodes, that was easily the most failures I had getting the lines out. 

But I did (eventually), and we wrapped the series. So again, thanks to Nicole Sweeney and Nick Jenkins for making me look like a dork. If you want more, Outtakes One, Two, Three, and Four exist as well.

By the way, the entire CCA series is now online. When you’re done binging whatever’s on Netflix, give this one a shot. The whole Universe is waiting for you.

Categories: Astronomy Headlines

By the Light of the Zodiac

Fri, 01/29/2016 - 06:15

Given how much time I’ve spent outside at night looking up, it’s funny to think there are still quite a few phenomena I’ve never seen. One that’s very near the top of my list of “Must See” things is zodiacal light.

This is the glow of dust and particles shed by comets, ones that orbit the Sun on relatively short paths. Over time these objects are influenced by the gravity of Jupiter, so we call them Jupiter-family comets. Made of ice and rock, they shed this material as the Sun warms them. Eventually, this stuff suffuses through the inner solar system, sticking pretty close to the same orbital planes as the planets, forming a flattish disk.

From Earth, we see the material reflecting sunlight back to us, glowing in a band across the sky. The photo above, taken at Mauna Kea by Rogelio Bernal Andreo, is one of the best shots I’ve seen of zodiacal light. It’s very faint, so you need dark skies — which the volcano provides (I think the faint streak across the middle is from a satellite).

Now follow along here: The planets, including the Earth, orbit the Sun on pretty much the same plane (from the side, the solar system’s planets’ orbits look flat). From the Earth, it looks like the Sun moves around us once per year. The path it takes across the sky is the same year after year, and we call this the ecliptic. The planets all move across the sky in that same path, too.

So, like clockwork, the Sun passes into the same constellations at a certain time every year. You know the names of these constellations: Sagittarius, Libra, Scorpius, Aries, Gemini… the constellation of the zodiac, or, if you prefer, the zodiacal constellations.

Since the glow we see from the cometary dust is also in this same plane, it too sticks to the same constellations, and we therefore call it zodiacal light. How cool is that? Cool enough that after a few years spending time in some rock band, a guitarist decided to go back and get his PhD studying it.

Interestingly, the dust we see is not constant. Solar wind, interactions with Jupiter, and other effects would eventually blow it all away. It’s replenished by more comets coming in and renewing it. I found a paper describing this, and the astronomers found that the amount of dust injected into the cloud must be around 100,000 kg per second. That’s a stunning three billion tons per year!

Mind you, that’s spread out over a lot of volume. Like, trillions of cubic kilometers at least. So it’s pretty thin stuff… but thick enough to be seen, at least from Earth on a dark, Moonless night, and photographed so that we humans can gaze upon it in awe and wonder about the marvelous working of our solar system. That’s a pretty good deal for us, I think.

Categories: Astronomy Headlines

And the David N. Schramm Science Journalism Award for 2016 Goes To …

Thu, 01/28/2016 - 09:12

I am very honored to let y’all know that I have received the David N. Schramm Science Journalism Award for 2016!

The annual award is given by the High Energy Astrophysics Division of the American Astronomical Society, the largest society of professional astronomers in the U.S., and is meant “to recognize and stimulate distinguished writing on high-energy astrophysics. The prize was established to improve the general public’s understanding of this exciting field of research.”

The award’s namesake, David Schramm, was an astrophysicist who studied the Big Bang. Much of his research involved how the lightest elements (hydrogen, helium, and lithium) were created in the first few moments after the birth of the Universe, and how those would affect other properties we see in the cosmos today. I never met him, but I wish I had; he sounds like he was an interesting fellow.

HEAD gave me the award for an article I wrote in Slate last year called, “A Supermassive Black Hole’s Fiery and Furious Wind,” about how the matter piles up and heats up around a black hole, which can blow off a ferocious wind of particles so strong it can sculpt the shape of the entire galaxy around it. Here’s an excerpt:

We also know that every big galaxy we look at has a supermassive black hole in its very center. If that black hole has gas and matter falling into it, the accretion disk can be huge and ridiculously, soul-crushingly bright. The luminosity of such an object can easily outshine the hundreds of billions of stars in the host galaxy,  and make the black hole visible clear across the Universe. This sets up an interesting problem. When you have a monster in the middle like that, how does it affect the rest of the galaxy? A curious fact was discovered many years ago; the mass of the black hole in a galaxy seems to correlate with how the stars in the galaxy orbit. You might think “duh” to that, but hang on. Even though a black hole can have a mass of a billion times the Sun, that’s a teeny tiny fraction of the mass of a galaxy with  a few hundred billion stars in it. Somehow, the black hole is affecting the galaxy around it on a huge scale. How?

If you want the answer, click through. I had a lot of fun writing that article. It covers a big, sweeping topic—why the sizes of gigantic black holes are apparently tied to the large-scale behavior of galaxies, which isn’t at all obvious—and uses new findings to help answer a question that had been bugging astronomers for years.

The field of high-energy astrophysics doesn’t have a hard and fast definition, but it covers objects and events that can generate high-energy light at the top of the electromagnetic spectrum: X-rays and gamma rays. These are among the most violent events in the Universe: exploding stars, colliding galaxies, gamma-ray bursts, black holes gobbling down matter, newly formed neutron stars glowing fiercely hot, and the like. I’ve always had a love for such brain-crushing events—probably spurred on by watching disaster movies as a kid.

I never did scientific research in high-energy astrophysics per se, but I was involved in the field for many years. Back in 2000, I left my job working on Hubble Space Telescope to move to California and be a part of the Sonoma State University NASA Education and Public Outreach group, headed by Lynn Cominsky. We developed educational products based on several NASA high-energy missions like Fermi, Swift, NuSTAR, XMM-Newton, and more.

It was (pardon the expression) a crash course on high-energy astrophysics, and I had a chance to learn so much about all these amazing astronomical objects and events from some of the top men and women in the field. I wrote tens of thousands of words for the Web, brochures, classroom activities, grant proposals, and even games we created. This was all in the service of educating teachers, students, and the public about the high-energy Universe, but it also filled a need in my own brain to find out as much as I could about all this fascinating science.

Whenever I write about black holes or gamma-ray bursts now, I’m reminded of my time learning about them back then. It’s nice to be able to tie together different times in my life and use them to help me in my writing.

I am deeply honored to accept this award, especially because it comes from my peers in the writing and scientific community, and I thank them sincerely.

Categories: Astronomy Headlines

The Dark Cloud of the Wolf

Thu, 01/28/2016 - 06:15

The space between stars is not empty.

Dark, cold, ghostlike material lurks there, as thin as a politician’s promise. Astronomers call this material “dust,” but don’t be fooled; it’s not like the little tumbleweeds you find under your desk. This stuff is made of grains of minerals and complex carbon-based molecules much like soot, created in the atmospheres of stars and blown out into the depths of space.

In the denser clouds of dust there might be a million particles in a single cubic centimeter of space. That may sound like a lot, but it’s one-ten-trillionth the density of the air you breathe.

Still, over hundreds of trillions of kilometers, even material this ethereally dispersed adds up. These grains and molecules of dust are very good at absorbing visible light, blocking it from passing through the clouds. As it happens, many of these clouds are located in the plane of our galaxy, the parts of our sky where stars are crowded together. When a cloud is between us and those stars, it looks like a hole in space, a place where the galaxy forgot to make stars.

The picture at the top of this article is one such cloud: Lupus 4, a vast filamentary structure 400 light-years away and about 10 light-years across. It was taken with the Wide Field Imager on the MPG/ESO 2.2-meter telescope at the La Silla Observatory in Chile, and the field of view is about a degree across: twice the width of the full Moon on the sky. That’s staggeringly big. Some people say it looks like a spider, but to me it more resembles some sort of cephalopod, its tentacles reaching out to us …

And that description is more apt than you might think.

Lupus is the constellation of the wolf, located not far from the center of the galaxy in the sky, where dust, gas, and stars are thickest. Lupus 4 is part of the sprawling Scorpius-Centaurus OB association, a loose cluster of massive stars that’s one of the very closest to Earth. These stars are young, and don’t live long; after a few million years they explode, scattering heavy elements into space.

A little while back, scientists studying ocean floor sediments examined a core taken out of the Atlantic Ocean seabed. They found a spike in an isotope of iron, called iron-60, dating to about 3 million years ago. Iron-60 is radioactive with a short half-life, and as far as we know only produced naturally in one place: a supernova. An exploding star.

That means either the material blasted away from a supernova swept over the Earth and deposited that material, or our solar system passed through a region of space where the blast wave from a supernova had stagnated (stopped after plowing through the material between the stars). Since iron-60 decays rapidly, either way it means this must have been from a cosmically young supernova.

As it happens, the stars in the Scorpius-Centaurus OB association are at the right distance to be implicated in this. Millions of years ago, one of them reached the end of its life, blew up, and sent material fleeing outwards at a substantial fraction of the speed of light. Some of that material managed to reach Earth, fall to the bottom of the ocean, and await our notice.

I mentioned that clouds like Lupus 4 appear to be where the galaxy forgot to make stars. But ironically, these clouds are generally the sites of star formation; it’s just hidden from us by the thick soup of dust. It’s possible that the star that blew up all those ages ago formed in a cloud just like Lupus 4 (perhaps in one of its neighboring clouds), and in death managed to physically touch our planet across four thousand trillion kilometers of space.

Like I said. Its tentacles, reaching out to us …

Categories: Astronomy Headlines

Team Celestron

Wed, 01/27/2016 - 09:00

I’ve liked Celestron for a long time; they make really nice optical gear like telescopes, binoculars, and more. A few years back they sponsored a couple of science panels I moderated when I wrote for Discover Magazine, and ever since then we’ve had a nice relationship. They also sponsor my company Science Getaways, for example. I have a few of their ‘scopes and binocs, and I love using them.

So I’m pleased and flattered that they asked me to join Team Celestron, a group of interesting folks who use their equipment. On that page you’ll find a few photos and videos I’ve taken through my ‘scopes, and some info about me, too.

Others on the team include Caroline Moore, the youngest person to discover a supernova; Thierry Legault, one of the single most gifted astrophotographers on the planet; and some physicist dude named Stephen Hawking.

As I mentioned in my Christmas telescope buying guide, the reason I’m happy to endorse Celestron is simple: I like their stuff. It’s good quality at a reasonable price, and if you take care of it you’ll have a scientific instrument that will last for many, many years. But it’s more than just for science: It’s fun

Categories: Astronomy Headlines

I’m Shocked—SHOCKED—to Find That Fluid Dynamics Is Going On Here!

Wed, 01/27/2016 - 06:15

On human spatial and time scales, stars seem motionless. Sure, they rise and set, but that’s a reflection (literally) of the Earth spinning on its axis once a day. But the stars themselves move, orbiting the center of the galaxy.

Stars are so terribly far away that this motion appears diminished to almost nothing; you need a telescope and lots of time to even measure it. But in real terms they’re hauling mass; the Sun, as an example, is moving at a staggering 220 kilometers per second around the galactic core. That’s three quarters of a million kilometers per hour!

In general, though, that motion has little effect on the galaxy itself. If you’re traveling through a vacuum, who cares? There’s nothing to get in your way.

But in reality there’s stuff in the way: The ethereally thin gas and dust between stars. This material makes a lab vacuum look like a thick soup; there may be only one atom for every cubic meter of space out there. Some places are denser, with hundreds or millions of particles per meter3, but even that is thin stuff.

But it adds up. And while a star itself is small, massive stars are hot, and blow a wind of particles out from them like a solar wind. This wind can extend for billions of kilometers, well out into space.

Now combine all this: Take a massive, hot star, let it blow a huge wind, and set it free to blast through space at hundreds of kilometers per second. What do you get?

You get what you see in the photo at the top of this post: a shock wave. Like water flowing around the bow of a ship, the interstellar material gets compressed in a vast curve in front of the star. I’ve written about this before; one of my favorite astronomical photos of all time shows the massive star Zeta Ophiuchi ramming through material in space, creating a spectacular bow wave.

The material warms up and glows in the infrared, making it easy to spot with space observatories like Spitzer and WISE, which are both sensitive to those wavelengths. Astronomers combed through the data, identifying over 200 such curved structures. Follow up observations on 80 of them showed they were due to speedy massive stars (some are created in other ways, like patchy gas and dust around a newborn star compressed by the baby’s violent outbursts).

One such wave they found is pretty cool; it’s actually from two stars. Seen here, the stars are HD240015 and HD240016, and the waves overlap, like a curvy M. The stars are both B-types, hotter and more massive than the Sun. However, I couldn’t find much info on them. They must be related, perhaps born in the same cluster. Usually, stars moving fast enough to create these waves were ejected from clusters, tossed out by a close encounter with another star, given a velocity boost by the gravity of the combined masses of all the other stars. I wonder if these two were together when they were kicked out, now traveling through the galaxy as a matched pair.

I like studies like this. We learn about the way stars emit material, how they move through space, and just what they’re moving through. And we also get such cool images! It’s a reminder that the Universe is in constant motion, and the scales are vast. And it helps personally, too. I figure if an octillion-ton star can rocket through space at dozens of times faster than a rifle bullet, I can probably be coaxed out of my chair every now and again and move around a bit myself. 

Categories: Astronomy Headlines

A City of Stars

Tue, 01/26/2016 - 08:45

My love of globular clusters is on record. Of all the objects in the deep sky—that is, outside our solar system—they are the ones that, through a telescope, look most like what they’re supposed to look like.

Nebulae are great, and so are galaxies, but when you look at them through an eyepiece of a typical small telescope you usually only see a faint smudgy thing. But when you get a globular in the crosshairs, you see it. Thousands of stars packed together so tightly that the center looks like a continuous blur of light, fanning out into a splendor of luminous points as you look farther out from the core. The overall sensation is of a beehive frozen in time.

Of course, having a big telescope helps, too. The image above is by my friend Adam Block, who used the 0.81 m Schulman Telescope at the Mt. Lemmon SkyCenter in Arizona to take it. It’s a total of six hours of exposure time (two hours each using red, green, and blue filters), and to be honest I’m not sure how many stars you can see in it. Tens of thousands at least. Maybe 100,000.

This picture is a little unusual, in that stars are resolved right down to the core. I’m not used to that in pictures taken from the ground; from Hubble, sure, because there’s no air to blur the image. Adam must have had really steady skies when he took his exposures.

Globular clusters are massive cities of stars, held together by their own gravity, each orbiting the center like, well, like a bee flying in circles around a hive. More than 150 of these clusters orbit the Milky Way galaxy, and some huge galaxies have thousands (though they probably stole them; stripping them from smaller galaxies as they eat the less massive prey, absorbing them into their own bodies).

I’d go into detail here, but I already have once before in Episode 35 of Crash Course Astronomy:

M15 was always one of my favorites to observe, and Adam’s picture makes me want to see it again with my own eyes. Sadly, it’s already low to the west at sunset this time of year and will soon be behind the Sun. But in a few months it’ll be high in the east again at night. That’ll be when the weather is warmer here in Colorado, more conducive to long nights behind the eyepiece. 

Categories: Astronomy Headlines

So, About that Video of the Space Station Passing in Front of Saturn…

Tue, 01/26/2016 - 06:15

Last week, a seemingly spectacular astronomy video went viral. It was created by a German astrophotographer named Julian Wessel, and it showed the International Space Station passing directly in front of Saturn. I saw links to it all over Twitter and Facebook, and no wonder: Catching such an event takes an extraordinary amount of skill and planning. Plus, it’s just cool.

There’s only one problem: It wasn’t real.

Wessel used images from different observing sessions and composited them together to make the video and the image. Under some circumstances this is OK — for example, when different telescopes are used, or when you’re reconstructing a scene (like the Earthrise image taken by LRO). But in any case, the important bit is to note that it’s a composite.

Wessel didn’t do this; on his website he said, "I managed it [sic] to photograph the ISS in front of a planet again. In this case it was the Lord of the Rings: Saturn." He also wrote, "Fortunately everything happened as planned and I could make the capture... You can see the Video of the Event on my YouTube... This is a great effort for me as an astrophotographer. It takes time, patience, preperation and a little bit of luck to get a shot like this, but at the end the hard work pays off!" That certainly makes it sound like he got footage of the actual event. He also submitted it to the Astronomy Picture of the Day site, which ran it (though, after review, they have since taken it down).

The video was convincing enough that it got past a lot of people. When I first saw it I was amazed, but it also set my skeptic sense tingling. It bugged me that he happened to catch the ISS directly in front of Saturn in one frame of the video; the odds of that are pretty low. And it all looked too crisp and clean, but that wasn’t enough for me to declare it a fake.

However, not long after the video became public, a whole bunch of amateur astronomers were on the case. My friend Stephen Ramsden (who does solar observing) sent me a note letting me know that people were buzzing over some serious issues with the video. Also, Christopher Go, who is a phenomenal planetary astrophotographer, also pointed out many problems with the video. As a few examples:

  • The ISS should have been about twice as big as the disk of Saturn, yet they’re the same size in the video.
  • ISS is far brighter than Saturn, but they appear equally well-exposed.
  • Saturn should have been grainy looking, noisy, due to the very short exposure.
  • At the time Wessel claimed to have taken the video, the Sun had just risen. The sky should have been very bright, and Saturn would have been extremely low contrast, almost washed out by the bright sky. Saturn was also very low in the sky, and atmospheric distortion should have made it look very fuzzy.
  • It was very cloudy that morning at the location Wessel claims to have taken the video.

I could list many more issues; most are pretty technical and circumstantial, but it’s a long list.

I sent Wessel an email asking him some specific questions, but I did not hear back. Not long after that, he removed the entry about the video from his site and Facebook, and removed the video from YouTube (which is why I didn’t embed it in this post) He also posted to an astrophotography forum, saying the image was a composite, but that doesn’t jibe with the claims he made earlier, which purport it to depict the actual event.

I don’t know what Wessel’s motivations are, and I won’t speculate. I will note that others are looking at some of his previous work and calling foul on that as well. Update, Jan. 26, 2016: Wessel has posted in the APOD message board apologizing for what he did.

But I’m writing about this because I think it’s important to note that it’s easy to get fooled. Software is so good that stuff like this can be created pretty easily, and it can be good enough to fool people passingly familiar with astrophotography, at least at first (though generally not for long, as we’ve seen here). But for people who don’t know much about it, this kind of stuff gets believed, and passed around social media rapidly.

That bugs me for a couple of reasons. One is simply about the nature of truth: People shouldn’t create fakes and then claim they’re real, and if they do then it should be called out. But more, it diminishes the actual photographs, the actual videos, and the very very hard work astrophotographers put into their craft.

For me, I love to share the joy and wonder of the Universe, and when artwork or fakes or computer simulations get passed around as the real thing, it diminishes what’s really going on around us. I prefer to appreciate things as they are.

A lot of fake astrophotographs get shared on social media (especially by those spammy Twitter feeds with handles like SciencePorn and Uberfacts, and usually with no links or credit to the original creator). I know a lot of people love seeing these pictures, but I think it’s important to separate fact from fiction. The Universe is actually and truly a stupendously gorgeous and astonishing thing all on its own. We can appreciate artwork depicting it, but we should also understand what’s real and what isn’t.

And here's some irony for you. As I was drafting up this article, I got a note that Szabolcs Nagy was in fact able to catch ISS transiting Saturn on Jan. 25 in Gran Canaria! Here's the video:

Yes, I checked, and this one looks real! It is possible to get this sort of thing on video. Like I said, it takes patience and planning, and maybe a bit of luck, too. See? Astronomy is really cool.

I suggest following FakeAstropix and PicPedant on Twitter to see if that viral pic you saw on Facebook is real or not. 

I’ve also written about fake pictures many times. Here’s a selection:

An Unreal Picture of Sunset at the North Pole (extremely viral drawing)
An Unreal Mars Skyline
Planetary Alignment Pyramid Scheme
A Fake and a Real View of the Solar Eclipse… FROM SPACE!
No, That’s Not a Picture of a Double Sunset on Mars
No, That’s Not a Real Photo of an Aurora from Space

But sometimes they are real:

Is That Viral Quadruple Rainbow Picture Real?
Yes, That Picture of the Moon and the Andromeda Galaxy Is About Right
An Eclipse of a Different Kind
And, finally, anything Thierry Legault does.

Categories: Astronomy Headlines

Lady Science

Mon, 01/25/2016 - 08:30

This may come as a shock to you, but science has something of an issue with sexism.

I’ve written about this many times, and you can probably find a few hundred thousand more words about it elsewhere. The problems run a broad spectrum of issues, including pay, hiring practices, treatment of women in the lab/field/academic setting, publishing, the “leaky pipeline,” and more.

Worse, these issues have a long, entrenched, historical precedent. Even when we talk about them we run into problems, like highlighting exceptional women who break barriers, instead of all the women who came before them and paved the way.

That’s why I’m happy that Lady Science exists. As they say on their page, they are:

a multifaceted collaborative writing project focused on women in science, technology, and medicine. Our purpose is to highlight women's lives and contributions to scientific fields, to critique representations of women in history and popular culture, and to provide an accessible and inclusive platform for writing about women on the web. 

I’m all for that. The editors, Anna Reser and Leila McNeill, have collected many of the essays written and put them together into a new anthology called, of course, Lady Science, available for free at Smashwords. The essays are thoughtful and interesting, and anyone interested in the stories behind science will enjoy them.

I’m also pleased to note that McNeill and Reser asked me to write the foreword to the anthology. That may strike some as odd; I’m a middle-aged bearded white man, pretty much the archetype stereotypical portrayal of a scientist. But sexism isn’t a women’s problem, it’s a problem for everyone. Also it helps if men speak up, because men who might be a part of the problem will tend to listen to other men more than women. Ironic, but once this idea gets traction with them that problem itself might diminish.

So I wrote the foreword, and Reser and McNeill have graciously allowed me to reproduce it here (I added a few links for further info). Please give it a read, then go download the book.

Lady Science Foreword

When I was in grad school, we had a woman on our faculty.

Note the singular. A woman, out of roughly 15 or more full-time professors. The thing is, within statistical uncertainty this was about the average for astronomy departments at the time; until very recently the typical university astronomy department faculty ratio was about 9 men for every woman.

The reasons for this are legion; historically fewer women stay in astronomy, for example. But that just leads to the next question: Why do women leave the field? The reasons for that are legion as well; One study showed a lack of role models led to retaining fewer women over time. Other factors include bias in hiring women, bias in salaries, and the traditional gender roles played out in family life (women who are parents tend to leave science careers at a far higher rate than men).

When you read the essays in Lady Science, the historical roots of these problems become clear. Environmental sexism, stemming from entrenched male scientific authority, was pretty terrible a century ago, and still a huge problem today. I’ll let the men and women who have done the research and written those essays speak for themselves. There are ample examples.

But a point I see brought up in some of the essays is worth noting, and that’s the idea of celebrating “firsts.” It seems like a good thing, a way of acknowledging women who broke through barriers. Marie Curie, first female Nobel prize winner; Valentina Tereshkova, first female astronaut; Sally Ride, first American female astronaut; and so on.

While it’s important to acknowledge these women and their accomplishments, there’s a series of subtle problems with doing that as well: It spends a lot of energy and effort on only a select few women, it pushes aside the accomplishments of other women in that field who may not have received the spotlight, it implies that there were few or no women before the one woman who “made it,” and it still categorizes women into a subset of history that could be labeled “other.”

I’m guilty of highlighting “firsts” myself, and reading the essays in Lady Science really made me think about the pitfalls of doing that; it seems obvious in retrospect but completely invisible to me at the time.

That’s an especially pernicious aspect of sexism: You sometimes need an outside viewpoint to discover it, and even then it’s not a lock. You have to absorb the ideas, internalize them. That’s why I write about women’s issues in science. When I was younger I really was totally insulated and blind to the problems women face in life, let alone in pursuing scientific fields. Over the years, many of the wonderful women and men I’ve known have helped me better understand these issues. I’m still walking down that road, but I’m glad I know I’m on that road.

But even after all this time I sometimes stumble, or at least walk right into a pothole I didn’t know was there. The “Women’s Firsts” is only the most recent one. I think it’s still good to point out women who break barriers, but we have to be careful not to do so at the risk of minimizing anyone else.

Many of the women in the Lady Science articles are people I had never heard of, and this is a good opportunity to get to know them. If we focus only on the firsts we lose many of their stories. As time goes on we then lose the details on the inner workings of how women as a group, as members of a team, participated in and critically supported the greatest scientific achievements of our species.

Incidentally, I just checked: As I write this, my old astronomy department now has 30 faculty, and four women. That’s better than before, a trend in the right direction. It’s a long ways from parity, but as you’ll read in these articles, and as history has taught us, change rarely happens overnight. We have a long way to go, but increasing awareness may be the most powerful tool we have to help clear the path.

Categories: Astronomy Headlines