Bad Astronomy
The entire universe in blog form

Feb. 10 2016 9:00 AM

NASA’s 2017 Budget Request: The Good, the Bad, and the Same Old Same Old

NASA and the White House have announced their proposed budget request for the fiscal year of 2017 (the government year starting Oct. 1). As usual, there’s good news and bad news.

First, let me be clear: This is not NASA’s actual budget. Every year, the space agency gets together with the President’s staff and they hammer out a budget based on what they want to do. Usually there are some guiding principles, like beefing up commercial spaceflight, getting back to the Moon or going to Mars, things like that.

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In the meantime, in Congress, the House works out its own separate budget for NASA (and everything else in the federal government). Once approved in committee, it goes to the floor for approval by all the Representatives, and then that version of the budget bill goes to the Senate. They then work out their own version, both sides of Congress hammer out their compromises, and then finally, they present that to the President as part of the federal budget to approve or deny.

Got it? So the budget we’re hearing about now from NASA is just a request to Congress, and will very likely undergo changes, some big and many small. But change it will.

Also, all of this is a bit of a hot take from me, a quick look first impression of what’s what. As time goes on we’ll get more of a sense of what these numbers mean… and what Congress is likely to say about them (for another take on all this, see my Alan Boyle’s summary at Geekwire, Casey Dreier’s at The Planetary Society and also Jeff Foust’s at SpaceNews).

So, given all that, what have we got? Let’s look at the biggies first.

SLS
Artwork depicting an SLS launch, sometime in the future.

NASA / MSFC

Overall, the budget requested totals just over $19 billion. That’s down from last year’s enacted budget of just under $19.3 billion, but is also the highest request the President has ever made. So yay? Kinda? As always, I’d like to see NASA’s budget doubled. Remember as you read everything below, NASA’s budget is less than one percent of the federal budget. That’s a good thing to bear in mind.

Space Launch System, or SLS, is the heavy lift launch rocket NASA is developing, and Orion is the capsule being developed with it that will carry humans into space. The requests for the two this year are $1.31 billion and $1.12 billion respectively. This can be compared to what was actually enacted for them last year: $2 billion, and $1.27 billion. That means the request is far less than last year’s funding, down by $690 and $150 million.

Personally, I am no fan of SLS. I’ve written about this many times; I don’t think this rocket is really needed, and it costs so much that very little money will be left over in NASA’s budget to actually do anything with it after it’s built (it’s like buying a car so expensive you can’t afford groceries).

However the Senate is very pro-SLS (some joke it’s actually the Senate Launch System).  Last year, the requested budget from the President for SLS was $1.36 billion, and Congress added $650 million to it! So I expect this request, like last year’s, will be heavily modified (added to) by Congress. This past year, Orion was actually funded at a higher amount than last year’s request as well.

Commercial Crew and Cargo (the part that funds companies like SpaceX and Boeing to take supplies and humans into space) gets a total of about $2.76 billion. The crew funding is down a bit from last year, but it looks like overall this will be a robust amount to fund these companies (the Commercial Spaceflight Federation agrees). I’m all for this; we rely on Russians right now to get our astronauts up to the International Space Station, and that is a terrible situation to be in. Commerical Crew gets mixed support in Congress; some Congresscritters support it strongly, while others do everything they can to slow it down and feed more to SLS.

As for science, that’s hit and miss. Astrophysics got a bump of $51 million over last year to $781 million, which is nice (the James Webb Space Telescope got less funding than last year, but that’s part of the planned-for needs of the mission; less money is needed next year than for the previous year). Heliophysics (studying the Sun) got a bump of just under $50 million to almost $700 million, so that’s good too.

Bizarrely, planetary science got slashed again by the White House. It drops from $1.63 billion to $1.52 billion, a cut of over $110 million. Mind you, this is the division that produced the successful flyby of Pluto last year. You may remember that. It’s a bona fide mystery why, year after year, the President’s request continues to try to cut what’s arguably the most successful part of NASA, both scientifically and in the public eye. My only hope is that, as they have done in previous years, Congress steps in and puts that number back to where it should be.

Europa
Jupiter's moon Europa; with a liquid water ocean beneath its surface, this may be our best bet to look for life on (or under) another world.

NASA / JPL-Caltech / SETI Institute

Incidentally, as Casey Dreier at The Planetary Society points out, a lot of this cut goes into the budget for the Europa mission (to Jupiter’s icy moon that has an ocean of water under its surface). It’s looking like the White House wants to fund an orbiter, but Congress has been clear on wanting a more expensive lander mission (I do too, duh). It’s not clear what rocket will be used there either; the Senate will want to use SLS, of course, while the President will want the Atlas V. I have my doubts that relying on SLS, a rocket that won’t be useable for nearly a decade, is a good bet. However, it would be able to launch a much more ambitious Europa mission and get it to Jupiter faster. So, I’m conflicted here, and have no obvious resolution to this mess (unless SpaceX gets their Falcon Heavy operating soon).

Earth science gets a boost this year in the request, up over $110 million from last year, to just over $2 billion. I wonder what will happen there when this gets to Congress? The total number may stay about the same (it did last year), but I would bet funding will be rearranged by Congress, since Earth science covers missions that study climate change. We know how the GOP-controlled Congress feels about that.

While Senator Ted Cruz (R-Texas) doesn’t directly control NASA money, he can influence what NASA does; mind you he is running for President under the banner of cutting government spending. He also has been beating the drums hard to promote his anti-science agenda. His counterparts in the House feel the same way, so I’m fairly confident this part of the budget will see some changes.

And maddeningly, NASA’s education arm suffers another big cut in this request, from $115 million enacted last year to $100 million. Madness. For some reason, the President’s office has been slashing this part of the budget year after year, and that’s just a terrible idea. Plain and simple. I worked in the education community using NASA funds for several years, and I saw first hand how much of an impact it had. NASA’s outreach efforts are part of why people correctly think of NASA as the shining example of humanity’s vision of exploration. Cutting that effort makes zero sense.

So for now, there we go. Again, these are some quick looks with my opinion added; I reserve the right to modify my opinions as more facts come in. We’ll see.

And again, remember how tiny a fraction of the federal budget NASA gets. Imagine if, instead of squabbling over pennies, we funded our space exploration at the level that it actually needs. What wonders would we see, what benefits would be reaped on Earth, how could we add to our compendium of knowledge about the Universe?

Per politicus, ad astra.

Feb. 9 2016 9:15 AM

New Study: Yup, Thermometers Do Show Global Warming Is Real

A common claim by climate change deniers is that scientists have been “altering” ground-based temperature data to make it look like the Earth is warming. This claim—which is not just wrong, but exactly wrong, as I’ll get to in a sec—has gotten more traction than most others offered by the forces of anti-science.

Rep. Lamar Smith, R-Texas, has been using this false claim as a blunt hammer against scientists in NOAA, for example, holding hearing after hearing trying to pin charges of conspiracy on them. But of course he’s wrong and is wasting huge amounts of taxpayer money pursuing a lie. As I’ve written before, the scientists aren’t “altering” the data, they’re correcting them.

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A new paper has come out reinforcing this. Researchers from Berkeley, the University of York, and NOAA have looked at the temperatures recorded at stations across the U.S. They assessed the corrections being applied to the data and have confirmed their accuracy. In other words, despite Smith’s claims, the techniques the scientists are using to calibrate the data are solid.

The basic idea is this: There are temperature stations all over the U.S., and many have been in use for more than a century. However, over the years, some have been moved, replaced, or their environment has changed. This, of course, changes the temperature they record.

To account for that, scientists apply a correction to the data to make sure that they are comparing apples to apples when looking at modern measurements versus older ones. But how do they know if the corrections are accurate?

Actually, there are quite a few ways, but in the new study the researchers looked at more modern stations that are known to be quite accurate and compared them to the data from nearby older stations during the 12-year period where the two different systems were both in operation at the same time. As was expected, the uncorrected data from the older stations didn’t match the newer ones well. However, when the corrections were applied, the older stations did in fact match the newer ones much better. This shows that the corrections being applied are in fact making the data more accurate.

temperatures
The average monthly temperature anomalies (deviations from an average) from 2004–2015. The new station readings are in green; the old ones using the correction are in orange. Note how good the fit is.

Hausfather et al.

Smith and his allies want you to think that scientists are nefariously altering the data, but that’s not the case. Calibrating data isn’t “altering” it. Think of it more like editing typos and bad grammar. Once those are gone, you get a far better picture of what’s actually happening*.

Interestingly, there are still some residual errors in the older measurements even after adjustments—that’s not too surprising; in the real world it’s almost impossible to completely correct such issues. But what’s funny is what the researchers found: Even after adjustments, the older systems still tend to underestimate maximum (and average) temperature trends compared with the newer systems during the overlap period)—consistent with other research that found the same trend.

This puts lie to Smith’s claims again. If scientists are altering the data to make it look like the planet is warming up, why would they underestimate the temperature trends?

The answer is obvious: They aren’t trying to make the planet look like it’s heating up. The planet is heating up, and they’re measuring that. That’s what the data are telling us, that’s what the planet is telling us, and as long as our politicians in charge are sticking their fingers in their ears and yelling “LALALALALALA” as loudly as they can, we’ll never get off our oil-soaked butts and get anything done to prevent an environmental catastrophe.

head in the sand
Not pictured: oil-soaked butt.

alphaspirit/Shutterstock

*Zeke Hausfather, the lead author on the new study, wrote about the methodology they’re using in an article for Skeptical Science last year, which has the details on all this if you’re interested.

Feb. 8 2016 9:30 AM

A Small Asteroid Will Definitely Miss Earth on March 5. But by How Much?

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 March 5.

The orbital mechanics on this are 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.

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

TX68 is a rock roughly 30 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 (nearly four 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 kilometers, but it could pass us 14 million kilometers away.

TX68 orbit
The best approximation we have at the moment for the orbit of TX68. It's not clear how far away it will be when it passes us (in the diagram, both Earth and TX68 orbit the Sun counterclockwise). The position marked for the asteroid was for early February.

NASA/JPL

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 kilometers 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 few centuries. 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.

* Correction, Feb. 9, 2016: I originally wrote that TX68 was 100 meters across; it's actually 100 feet or 30 meters across (the error is my fault, but oh how I wish everyone used metric!). That changes the statistical frequency of impact from millennia to centuries. 

Feb. 7 2016 9:30 AM

Music of the Spheres

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 International Space Station, he put together this short video. “Final Frontier,” to do so.

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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 storytelling, 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.

Feb. 6 2016 9:15 AM

Edgar Mitchell, 1930–2016

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.

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.

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All 12 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 that 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.

Ed Mitchell on the Moon
Ed Mitchell, on the Moon.

NASA

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.

Feb. 5 2016 9:30 AM

Gigantic Space Telescope’s Main Mirror Now Complete

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.

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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.

Hubble vs JWST
Hubble's solid circular mirror (left) versus JWST's honeycomb.

NASA

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:

JWST mirror segment
One hexagonal segment of the JWST mirror; note the reflection of the door and window through which I shot this photo. CLick to enaurumenate.

Phil Plait

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.

Feb. 4 2016 9:15 AM

Is This the Biggest Spiral Galaxy in the Universe?

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.

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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 more than 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.

Malin 1 and Milky Way
That's a big galaxy.

Galaz et al., 2016/NASA/JPL-Caltech

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 o'clock 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?

Feb. 3 2016 12:13 PM

Science Ranch 2016

Update, Feb. 7, 2016: As of today, Science Ranch 2016 has sold out. However, we do maintain a waiting list in case spots open up. If you want to be on the list, please contact us!

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.

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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.

bighorn sheep
Bighorn sheep are a common sight in the hills next to the ranch.

Sylvan Dale Guest Ranch

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.

horseback riding
The ranch sits on a huge chunk of land that goes into the hills, and you can ride horses up there.

Sylvan Dale Guest Ranch

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.

Feb. 3 2016 9:30 AM

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

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.

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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.

trajectory of Smith
The path of the cloud over the past and future.

NASA/ESA

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.

galactic fountain
An infrared map of the galaxy reveals a blowout: A popped bubble of gas (lower left) that could be the origin of a high-velocity cloud.

ESA/Hi-GAL Consortium

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.

Feb. 2 2016 12:00 PM

Mars From a Height

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.

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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.

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