The entire universe in blog form

Sept. 30 2014 7:30 AM

What Lurks Beneath the Methane Lakes of Titan?

One of the biggest discoveries made by the Cassini spacecraft is that Titan—the mammoth moon of Saturn—has lakes of liquid methane and ethane on its surface. Radar maps of the surface of Titan confirmed that the north pole is dotted with them, and combined cover far more of the surface of that moon than the Great Lakes do the Earth.

Smooth lakes of liquid natural gas don’t reflect radar waves well, so the maps made of Titan show the lakes as dark. Cassini’s instruments are sensitive enough that they have even ruled out constant waves on the lakes; they would show up as bright streaks in the images. The lakes are extremely smooth.

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So what’s going on with the images above? In 2007, radar maps showed Ligeia Mare very near the moon’s north pole, looking pretty much as usual. The lake looks dark, and solid material (land) shows up as white. But in 2012 a new feature appeared, just off shore! It disappeared, but then turned up again in radar maps taken in 2014 … but shaped differently.

What the what? What are we seeing here? Fun answer: No one knows.

Scientists have apparently ruled out errors in the imaging techniques or artifacts in the detector, meaning whatever this thing is, it’s real.

cassini_titan_sea_feature_3panel
Same as above, but with a newer image from 2014, showing how the event, whatever it is, has changed shape.

Photo by NASA/JPL-Caltech/ASI/Cornell

It could be any number of things. Clearly it’s some transient feature, something that can come and go. That indicates it’s probably not solid land. It could be waves, or some sort of solid material just beneath the surface (methane ice)?

My first thought was bubbles, and I was pleased to see this on the list of candidates. Titan has seasons, and summer is coming for the moon’s northern hemisphere. The warming temperatures could be releasing bubbles buried in sediment under the lakes, for example, or the liquid could be warming up enough to release dissolved gases.

Right now no one knows, which is wonderful. A mystery! And it’s a good one.* Saturn and its system are full of ‘em. But what this does show is that even in the outer solar system, where temperatures reach a balmy -180° C, worlds can still be dynamic, interesting places. So much so that even after 10 years in orbit there, Cassini still has the ability to amaze and delight us.

*I’ll admit I’m still hoping for sea monsters. The biggest lake on Titan is named Kraken Mare!

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Sept. 29 2014 12:01 PM

This Is Your MOM’s Mars

Holy. Ares!

THAT is a full-disk image of Mars taken by India’s Mars Orbiter Mission, or MOM. It was just released this morning and shows nearly an entire hemisphere of the planet.

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It’s gorgeous. There’s so much to see! North is to the upper left (roughly the 11:00 position), and the pole looks like it’s covered in a cloudy haze [Update (Sep. 29, 2014 at 17:40 UTC): Ah, according to my friend and fellow science writer Carolyn Collins Petersen, that's a dust storm brewing there.]. The huge, lighter-colored region just to the right and above center is called Arabia Terra, a 4,500-kilometer stretch of uplands that is one of the oldest terrains on Mars. It’s hard to tell from this wide-angle shot, but it’s heavily eroded and covered with craters.

Just below it is a long dark feature called Terra Meridiani (“Meridian Land”; though you could fancifully call it “Middle Earth”). The rover Opportunity is there, still roaming around and poking at the rocks there. This whole area shows evidence that is was once under water.

Nestled in the northern part of Terra Meridiani is the crater Schiaparelli, which is more than 460 km across! That’s huge, far larger than the crater left by the dinosaur-killer impact here on Earth. Straight up from it in Arabia Terra you can also see the crater Cassini (also more than 400 km wide), and to the right, just inside the dark region called Syrtis Major, is the crater Huygens, which is about the same size as Schiaparelli. The astronomers Cassini and Huygens studied Saturn, which is why the Cassini probe is named what it is, and the lander probe it sent to the moon Titan is named Huygens. Those astronomers really get around.

I could go on and on; you can see Hellas Basin as a smooth, butterscotch-colored area to the lower right just on the edge, and the ices of the south pole at the bottom. There are craters galore, and all sorts of wind-eroded areas that so many scientists will happily spend the rest of their lives studying.

But for me, right now, what makes me sigh in awe is the overall perspective of this picture. We’re seeing the entire face of the planet here, a perspective we don’t always get from our probes, sent to study Mars in detail. And the added touch of it not being fully lit—you can see the day-night line, called the terminator, cutting across the planet to the upper left—really drives home that what we’re seeing here really is an entire world, a huge expanse of territory just calling out for us to explore and understand.

There’s a lot of solar system out there to look at, and it fills me with joy to know we’re doing just that.

Sept. 29 2014 8:00 AM

Where Will We Find Extraterrestrial Life First?

Here’s an interesting question: Where will we find life outside Earth first? In our solar system, on worlds like Europa, Enceladus, Titan, or Mars; signs of it from an exoplanet; or possibly even signals from intelligent civilizations?

Science communicator Katrina Jackson sat down with two astrophysicists—my friends Michelle Thaller and Neil Gehrels—to talk about exoplanets and the search for life. It’s a short video but a very intriguing one.

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(Note: This is one part of a longer conversation that covers more topics).

I wonder about this question as well (who doesn’t?). It’s a bit complicated, because we don’t know if life exists outside Earth in any of these ways. But for fun let’s assume it does. Which would happen first?

Right now, we’re not terribly well equipped to do a thorough search for life on worlds in our solar system. The rovers on Mars don’t have the right equipment to unequivocally detect signs of life. Anything they find short of macroscopic fossils would probably be indirect (say, chemicals in rocks indicative of biological processes). The evidence they find probably wouldn’t be conclusive either, so we’d be arguing for a long time over whether it was due to life or not. (This isn’t a guess; results from tests done by the Mars Viking landers are still argued over, and those tests were done in the 1970s.)

It’s the same problem for exoplanets. I’m excited about WFIRST, which is a proposed space telescope that can directly image exoplanets and get spectra of them (JWST will, too), which can detect the chemical signatures of elements and molecules in the atmospheres of the planets. If they find oxygen, that would be pretty spectacular! As Michelle says in the video, oxygen is highly reactive, and the best way we know to have it in an atmosphere at decent levels is through life. But as Neil points out, there may be things we don’t know, and the arguing will continue (and most likely justifiably so) even when the data are in hand.

As for SETI, they mention Seth Shostak, who has predicted that if intelligent life exists in the galaxy, and is broadcasting, we’ll find them in the next couple decades. It’s a bold prediction, based on current tech and our ability to improve our techniques. If we find a signal, what then? I wonder. If it’s a strong, clear signal (like in the movie Contact) then we’ll be pretty sure what’s what. But what if it’s weak, or noisy, or ambiguous in some way? We’ve had false hopes before (as Neil mentions in the video). It could very well be that what we find isn’t as clear as we hoped.

Because of all this, in the end, I’m not sure which way will produce the first, best results. And that’s assuming life is out there to begin with! The obvious solution is to keep looking in as many ways as we can. If life is out there, and it’s recognizable, it only makes sense to keep our eyes—and our minds—open.

Sept. 28 2014 7:00 AM

Japanese Volcano Eruption Caught on Video … VERY Up Close and Personal

If you’ve ever wondered what my nightmares are like, they pretty much go like this.

On Sept. 27, a group of hikers was enjoying the fall weather on the Japanese volcano Mount Ontake. Suddenly, the volcano erupted, letting loose an incredible pyroclastic flow, a torrent of superheated ash that barrels down the slopes of the volcano like a thundering wall of death. The hikers tried to get away, but the flow was far faster … still, one of them managed to get video.

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(Yes, it's vertical, so turn your head. And give the videographer a break, they were all literally running for their life.)

My heart was pounding in my throat watching that; ever since I started reading about volcanoes years ago, pyroclastic flows fill me with visceral terror. They are implacable and unyielding; my friend and geologist Mika McKinnon calls them “rolling clouds of murder.” It is almost beyond imagination that the hikers survived. In fact, given how many people were on the mountain that day, it’s truly remarkable anyone survived. However, there have been no confirmed deaths as I write this (one had been reported but was subsequently retracted). Update, Sept. 28, 2014 at 15:00 UTC: Well, damn. I'm very sorry to add that overnight reports say that least 31 people have been killed by the eruption. Here is more information on what may have happened, written by volcanologist Erik Klemetti.

I’d write about the science behind all this, but Mika has already done an outstanding job on io9.

I love volcanoes; they are fascinating and something about them draws me in. I will happily travel to see more … but as I do, something like this will always be at the very least at the back of my mind. As long as it isn’t literally at my back.

<shudder>

Sept. 27 2014 7:30 AM

A Night of Science and Silliness

I have good news if you like fun things! And if you live somewhere near the San Francisco Bay area.

On Oct. 25 I’ll be at the Castro Theatre to do not one but two science comedy events: BAHFest and the Quiz-O-Tron 9000! Both are part of the Bay Area Science Festival, a weeklong celebration of science. Or, in the case of these two events, the mocking of it. To wit:

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1) BAHFest is the Festival of Bad Ad Hoc Hypotheses, which is the brainchild of that ginger fiend Zach Weinersmith, creator of the Saturday Morning Breakfast Cereal comic. The gist is that people come up with terrible science-based just-so stories to explain something, then present it to the audience and judges. To give you an idea of how this goes, read the SMBC comic that inspired it.

I will be a judge at this, and I will be harsh but fair. (Note: I will be neither.) The keynote speaker is Matt Inman, who draws The Oatmeal, so c’mon. This will be amazing.

For tickets and such, go to the BASF BAHFest page. I know Zach and I will have books and stuff to sell and sign after the event, as will Matt and probably others.

b) Quiz-O-Tron 9000 is a snarky quiz show hosted by my friend and noted MRA enemy Rebecca Watson. She asks panelists about current science news topics, and the person with the most points at the end of the show (generally arbitrarily assigned by a judge with a tenuous grip on events) wins. I’ve done this a few times at DragonCon, and it’s a lot of fun (see these photos for evidence of such funnery). It’s also decidedly adult, so fairly warned be thee, says I.

I’ll note I am the Reigning Champion of the Universe for this game, and I have the belt to prove it. I’ll be bringing the belt with me, only so I can mock the other panelists when I take it home with me again.

I’m really excited by this. This will be a fantastically fun night, so don’t miss it.

Sept. 26 2014 7:30 AM

The Oldest Known Star in the Universe

Astronomers have found the oldest star in the Universe. Well, kinda. It’s the oldest one we know of. At least the oldest one we know of for which an age has been reliably measured.

OK, enough caveats. What’s going on?

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Some stars are young; we see them being born now. Some are middle-aged, like the Sun, which is about 4.56 billion years old. It’ll be good to go for another 6 billion years or more (though more on that in a moment).

And some are old. Very old. Up until now, the oldest star that has had a reliable age measured for it is about 13.2 billion years old. It was already old when the Sun was just starting to fuse hydrogen into helium.

But astronomers have just published a paper about a star that is even more elderly: HD 140283, which appears to be 14.3 billion years old.

Now, before you start quoting that number for the next edition of the Guinness Book of Cosmic Records, you might want to note that the Universe itself is only 13.82 billion years old. Clearly, something must be off here.

The answer is that the age of the star is off. That takes a moment to explain.

When the Universe was young, just a few hundred million years old, it was a bit simpler. The main stuff floating around was hydrogen and helium. There weren’t a lot of other elements yet because there hadn’t been enough stars to make them! Elements heavier than helium* were created in the first stars, and then scattered into the cosmos when those stars exploded. These elements were then seeded into clouds of gas, which formed the next generation of stars.

Astronomers call all elements heavier than helium “metals,” which is dumb, but that’s what we’re stuck with. And as a rule of thumb, the older a star is, the fewer metals it has in it. We can measure the amount of such materials in a star by taking high-resolution spectra of it. Surveys have identified lots of stars with low metallicity, and three such stars were specifically targeted for the research, including HD 140283.

The advantages of looking at this star are many. For one, it’s near the Sun (less than 200 light years away), so the distance can be determined very accurately using parallax. Its location in the sky was clear of galactic dust, which can interfere with observations. And for another, it’s finally—finally—nearing the end of its life.

That’s important. A star like the Sun spends most of its time fusing hydrogen into helium in its core. But eventually that hydrogen fuel runs out. The core starts to shrink under its own gravity and heats up. That sends its temperature through the roof (so to speak), and it heats up the layers of the star above it. That causes them to expand, and so the star begins to get bigger. Eventually it becomes a red giant, but for a while, as it expands, it’s called a subgiant. This won’t happen with the Sun for several billion more years, but with HD 140283 it’s just starting to happen now. That’s convenient timing; we have excellent physical models for how stars behave when they turn into a subgiant, and that depends on their temperature, their brightness, and their age. Very careful analysis of the star has yielded the age measurement, and that’s how they got that it’s 14.3 billion years old.

But there are a number of difficulties with getting the age this way—it depends on factors like (oddly) how much oxygen is in the star, how much dust is between us and it, and other things. In the end, they calculate their error bars as about ±0.8 billion years.

What that means is that their formal calculation gives the age as 14.3 billion years, but 13.5 billion is just as likely the right number. It’s possible it’s younger than that, but not as likely.

Any scientist looking at that would then be perfectly happy concluding that the star is younger than the Universe. I am. And I’ll note that the previous record holder, called He 1523-0901, had an uncertainty that was a bit bigger than for HD 140283. All things considered, it’s reasonable to conclude HD 140283 is somewhat older.

So is it the oldest star in the Universe? That seems unlikely. It’s a big, big Universe, and the odds of the actual oldest star being a) in our galaxy at all and 2) that close to the Sun are essentially zero. Most likely we’ll find older stars the more we look. But since this isn’t an exact science what we’re likely to find is not a single oldest star, but a bunch of stars that are all about the same age to within uncertainty. And they’ll all be just a few hundred million years younger than the Universe itself.

And that’s pretty cool. The goal here isn’t to break the record, it’s to collect data for lots of stars so that we can understand what things were like back when the Universe was a wee baby, and how stars have changed in all the eons since.

When you step back and think about that for a moment, I hope the hair on the back of your neck stands up. Using astronomy and physics, we can understand the very nature of the Universe itself, from the moment it came to be, through all its adventures since, and then predict what it will be like in the vast, deep future.

Science! I love this stuff.

*Some lithium was also around, but in very tiny quantities, and it’s also easily destroyed inside of stars. So for the purposes of this discussion it doesn’t really count.

Tip o’ the dew shield to my friend Bond, Howard Bond, who is one of the authors on that paper.

Sept. 25 2014 7:30 AM

MAVEN’s Mars

As I write this, India’s Mars Orbiter Mission has been orbiting the red planet for just about a day, and NASA’s MAVEN for only three. I haven’t seen any images from MOM yet (UPDATE: see below), but the Mars Atmosphere and Volatile Evolution spacecraft took ultraviolet images just eight hours after achieving orbit, and they’re breathtaking.

MAVEN and Mars
MAVEN sees Mars breathe: Ultraviolet images of the planet's atmosphere will allow scientists to understand it better. Click to enaresenate.

Photo by Laboratory for Atmospheric and Space Physics,University of Colorado;NASA

Mars has an atmosphere, thin, but there. And it has different components to it, seen in different wavelengths (colors) of UV light.

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Hydrogen is the lightest element, and extends the farthest off the planet. Shown here colored blue (representing the shortest wavelength of UV), you can see it extends well off the planet’s surface (Mars is 6,800 kilometers—4,200 miles—across, for scale). Oxygen (in green) is heavier, and sticks closer. There isn’t much of it on Mars, and what there is comes from water (which is where the hydrogen originates as well) and carbon dioxide. I suspect the crescent pattern is due to limb brightening; near the edge of the planet we’re looking through more atmosphere, so the oxygen emission is more apparent there.

The red panel is reflected sunlight, and you can see a brighter ring near the pole that is either from clouds—Mars has those too, though very thin—or ice. The panel on the far right is the composite of all three images, an amazing portrait of our neighbor.

I literally sighed in amazement when I saw there; they’re lovely and fascinating and just so odd. Mars is such a weird little world.

But weird is in the eye of the beholder. MAVEN will orbit Mars and take scientific observations for at least a year, and we’ll get to learn quite a bit about the atmosphere of the planet as it does. Mars used to have thicker air and plenty of water; now they’re both almost all gone. Why? Why did Mars evolve so differently than Earth? We know it has to do with Mars not having a strong magnetic field as we do, so the solar wind was able to merciless strip away its air over the eons. But our understanding of the details is still lacking. That’s what we sent MAVEN to find out.

And it joins so many other probes currently examining Mars—including MOM, which I haven’t written much about, but of course Emily Lakdawalla at the Planetary Society has a fantastic article about it. There’s still so much to explore on Mars. And above it. Soon, we’ll have a more complete picture of it, and hopefully understand why, but for the whim of nature, go we.

Update, Sept. 25, 2014 at 14:00 UTC: Of course, between the time I wrote this article last night and the time it posted this morning, MOM released two great shots of Mars. The first shows a view of windswept craters over a bicolored landscape:

mom_mars_firstlight
MOM's Mars.

Photo by MOM/ISRO

The gray is due to dark basaltic rock, and the red from where the surface is covered in dust rich in iron oxide—rust.

The second shot shows the limb of Mars:

mom_mars_firstlight2
MOM on the edge.

Photo by MOM/ISRO

I love the caption posted from the MOM Twitter account: "A shot of Martian atmosphere. I'm getting better at it. No pressure."

I'm very excited to see what else India's first interplanetary mission has in store for us!

Sept. 24 2014 9:30 AM

Jon Stewart Puts the Heat on Congress

If you ever catch me in a moment of weakness about the weapons-grade dumbosity of global warming denial on the Republican side of the U.S. House of Representatives, it might look a lot like what Jon Stewart did on The Daily Show on the Sept. 22, 2014, show:

It’s become a cliché that majority members of the House Science Committee know nothing at all about actual science (or they do, but choose to ignore it for ideological reasons)—but here on display for all to see is just how ridiculous the reality of it is. What you just saw are long, long debunked denial points being brought up like they are revealed wisdom, along with “gotcha”-style barbs that are transparently, bone-headedly wrong.

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And isn’t presidential science adviser John Holdren a freaking ninja in those clips? He easily and smoothly shuts down the salvos of scientific ignorance tossed out by the committee members. For his part, I’m very glad Stewart pointed out the glaring hypocrisy of people like Rep. Larry Bucshon, R-Indiana, who accuses climatologists of faking the science for money, when Bucshon himself is funded quite well by fossil fuel interests.*

Holy oiliness. It’s loathsome enough that Bucshon would choose to simply ignore the agreement of the vast majority of climatologists who know the Earth is warming and that it’s our fault … but to do so while happily taking the Koch brothers' money is really galling.

If I seem upset about this, it’s because I am. It’s like we’re in some sort of alternate reality, a Hollywood spoof of what government is like. But it’s real, and these buffoons are holding up any real chance we have of making any progress about one of the (if not the single) largest problem we as a species face.

There’s an election coming up, folks. Vote. I know there’s essentially no chance that the GOP will lose the majority in the House, but it’s important to get out there and vote, and to get others to as well. If we don’t, then we’re just handing over our future to these people who have their minds firmly closed to reality.

*Correction, Sept. 24, 2014: This post originally misspelled the last name of Rep. Larry Bucshon.

Sept. 24 2014 5:30 AM

Holy Kilauea!

I travel quite a bit, and I’m privileged to visit some places of extraordinary beauty. Last week, I returned home from an exceptional trip to the Big Island of Hawaii. The proximal reason for the visit was to attend HawaiiCon, where much fun was had by all.

But as regular readers know, I am a sucker for volcanoes. Despite having been to quite a few, the ones I’ve seen personally are all quiet, either dormant or extinct. That all changed after the con ended, though. My wife and I drove across the island to visit the active volcano Mt. Kilauea, and it was nothing short of life-changing.

After spending some time at the ranger station learning about the volcano, we went to the Jaggar Museum on the summit, which had excellent displays about Kilauea. The museum is on the very lip of the gigantic caldera, which is several kilometers across.

Sept. 23 2014 11:00 AM

Google Exec: Climate Change Deniers Are “Just Literally Lying”

Well, how about that? In an interview on NPR’s the Diane Rehm Show, Google Executive Chairman Eric Schmidt comes right out and says that climate change deniers are “literally just lying.”

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When asked why Google funds the American Legislative Exchange Council—a conservative/libertarian group that supports all sorts of horrid ideas, and in this case specifically climate change denial—Schmidt said that Google first supported them for unrelated political issues. But it became clear they could no longer do so:

I think the consensus within the company was that that was some sort of mistake and so we're trying to not do that in the future.
Well, the company has a very strong view that we should make decisions in politics based on facts—[sarcastically] what a shock. And the facts of climate change are not in question anymore. Everyone understands climate change is occurring and the people who oppose it are really hurting our children and our grandchildren and making the world a much worse place. And so we should not be aligned with such people—they're just, they're just literally lying.

(Emphasis mine.)

Wow. I’ve known about Google funding ALEC for some time, and I’ve been conflicted about it. When companies give money to other groups, they do so knowing that not everything that group does aligns with what the company wants. In this case, though, I’m very glad to see Google pulling out from ALEC.

I suspect ALEC won’t be that hard off, though: They still get plenty of cash from the Koch brothers.

liar liar
Well, that's what you get when you deny warming.

Drawing by Igor Zakowski/Shutterstock

Another such case of Google dancing with the devil is in the form of Sen. James Inhofe, R-Oklahoma, probably the loudest and most ludicrous global warming denier in the Senate. Google held a fundraising campaign for Inhofe, which doesn’t really surprise me; again, sometimes as a company you have to make decisions like that.

I can hope, though, that after parting ways with ALEC, they can do so with Inhofe, and other head-in-the-sand politicians when it comes to the current and ongoing global warming crisis. Forecast the Facts points out that Google has funded deniers like Inhofe to the tune of nearly $700,000 since 2008.

Perhaps more public awareness will help Google see this is not a great idea.

By the way, Inhofe called human-generated global warming “the second largest greatest hoax ever played on the American people, after the separation of church and state,” a statement that makes my eyes roll back so far in my head that I can see the back of my skull. In case your irony gland is still intact, I’ll remind you that Inhofe did, for some time, chair the Senate Environmental and Public Works Committee. If Republicans win the Senate in November, he may very well do so again.

The U.S. midterm election for Senate and Congress is in six weeks. When going to the polls, keep Inhofe and his ilk in mind—kick him and the rest of the reality-stomping politicians to the curb.

Tip o’ the thermometer to Juliet Eilperin on Twitter.

Correction, Sept. 23, 2014: The title of this article originally referred to Schmidt as Google CEO.

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