No, That’s Not a Real Photo of an Aurora From Space

Facebook is to misinformation what a high school is to mono. Basically, it gets in there, and boom! Everyone shares it.

The culprit this time is a picture claiming to be an aurora taken from space. Here’s the photo:

I saw this linked from a Facebook page called ScienceDump, one of those accounts that posts pictures that are vaguely sciencey, and only sometimes gives links to further info or attribution for the images.

In this case, the only caption given was, “Ring of Fire. A picture taken by NASA of the Northern Lights from space.”

I knew right away that caption was completely wrong. For one thing, the Earth, stars, and aurorae simply don’t look real. Note the complete lack of clouds, for example. Second, the aurora aren’t that tall; those streamers are hundreds of miles in height, but in reality aurorae sheets are only a few miles in height.

I did a reverse image search using Google, and at first just found the usual reshares of this photo. I did find a few sites debunking the picture, but none knew where it was from. My biggest clue came from the sattrackcam blog, which dissects the image pretty well, but also mentions the shot was used in a video.

That gave me an idea. NASA’s Goddard Space Flight Center has an excellent video team, and I know a lot of their animations are online. I started poking around on their site, and it took a little while, but I finally found the exact original video this image is from!

The image comes in at the one-minute mark. The whole video is clearly computer generated. In fact, there’s a credit at the bottom of the GSFC page: “Visualizer/Animator: Walt Feimer (HTSI) (Lead)”; HTSI is for Honeywell Technology Solutions Inc. The video was created under contract to depict how the Earth’s magnetic field channels subatomic particles from the solar wind down into the atmosphere, where they make the air glow.

It only took me a few minutes to figure this all out. I did have the advantage of knowing about GSFC’s video page, but this ScienceDump page didn’t bother with fact checking or credit at all. Whoever runs it just made up a caption and ran with it. I’m no fan of these kinds of accounts; I see a lot of them on Facebook and Twitter, posting blatant garbage and claiming it’s real. ScienceDump appears to be marginally better than most, linking offsite to other sources. But this aurora photo shows it’s not 100 percent.

A good antidote for all this is to follow @FakeAstroPix and @PicPedant on Twitter (want a chuckle? Check out PicPedant’s background picture on their Twitter page; I could’ve saved myself some effort). @HoaxOfFame looks good, too. And, of course, there are hundreds of science communicators out there you can follow on social media to get the real scoop on real science.

I know that urge to retweet and share these kinds of photos can be strong, but I urge you not to subscribe to those kinds of accounts. Don’t get me wrong: It’s nice to get people excited with cool pictures and factoids, but from what I can see a lot (many? most?) of these sorts of accounts just post pictures while rarely giving credit or explaining them. And worse, a lot of them post total nonsense and even faked pictures, passing them off as real.

I’ve said this before, but it’s probably worth saying again, many times: The Universe is cool enough without making up crap about it.

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Help U.S. Cope with Climate Change: Enter NASA-USGS Data App Challenge

NASA in partnership with the U.S. Geological Survey (USGS) is offering more than $35,000 in prizes to citizen scientists for ideas that make use of climate data to address vulnerabilities faced by the United States in coping with climate change.



December 11, 2014

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Colorful and Plankton-full Patagonian Waters

Late spring and summer weather brings blooms of color to the Atlantic Ocean off of South America, at least from a satellite view. The Patagonian Shelf Break is a biologically rich patch of ocean where airborne dust from the land, iron-rich currents from the south, and upwelling currents from the depths provide a bounty of nutrients for the grass of the sea—phytoplankton. In turn, those floating sunlight harvesters become food for some of the richest fisheries in the world. The Visible Infrared Imaging Radiometer Suite (VIIRS) on Suomi NPP captured this view of phytoplankton-rich waters off of Argentina on Dec. 2, 2014. Scientists in NASA’s Ocean Color Group used three wavelengths (671, 551, and 443 nanometers) of visible and near-infrared light to highlight different plankton communities in the water. Bands of color not only reveal the location of plankton, but also the dynamic eddies and currents that carry them. > More Information Image Credit: Norman Kuring, NASA’s Ocean Color Group, using VIIRS data from the Suomi National Polar-orbiting Partnership via NASA http://ift.tt/1slHCNZ

Is Earth’s Water Locally Sourced?

We call Earth a water world, and that’s pretty fair: Our planet’s surface is 70 percent covered in it, it makes up a percentage of our air, and there’s even a substantial amount of it mixed in to the planet’s mantle, deep underground.

But where the heck did it come from?

This is no idle question. We have a lot of water here, and it must have come from somewhere. There are two obvious sources—it formed here along with the Earth, or it was brought to Earth from space. Which is the dominant source has been a topic of long and heated debate among astronomers.

The first big science results have just been announced by the European science team working with the Rosetta probe, and, in my opinion, they throw more gasoline on the fire. Measurements made by the probe show that comets like 67P/Churyumov–Gerasimenko—the one Rosetta is orbiting—couldn’t have been the source of our water.

But that hardly helps answer the underlying question! Why not? Ah, the details…

When the Earth formed 4.55 billion years ago (give or take), there was a lot of water in the disk of material swirling around the Sun. Close in to the Sun, where it was warm, that water was a gas, and farther out it formed ice. We see that latter part echoed down through time now in the form of icy moons around the outer planets.

You’d expect water collected on Earth along with everything else (metals, silicates, and so on). When the Earth cooled, a lot of that water bubbled up from the interior or was outgassed by volcanism.

But we have another big source, too: comets. These are dirty snowballs, rock and dust held together by water frozen as ice. They formed farther out in the solar system, where ice was more plentiful. Long ago, just a few hundred million years after Earth formed and started to cool, there was a tremendous flood of comets sent down into the inner solar system, disturbed by the gravitational dance of the outer planets as they slowly settled down into their orbits. This Late Heavy Bombardment, as it’s called, could have supplied all of Earth’s water.

How to tell? Well, it turns out that in this one case, hipsters are right: Locally sourced is measurably different than stuff trucked in.

Water is made up of one oxygen atom and two hydrogen atoms. Hydrogen atoms, it so happens, come in two flavors: The normal kind that has single proton in its nucleus, and a heavier kind called deuterium that has a proton and a neutron (there’s also tritium, with two neutrons, but that’s exceedingly rare). Deuterium is far more rare than the normal kind of hydrogen, but how rare depends on what you look at. The ratio of deuterium to hydrogen in Earth’s water can be different than, say, water in comets, or on Mars.

Note I said, “can be”. We know the ratio differs across the solar system. But suppose we find the same ratio in comets as we do on Earth. That would be powerful evidence that water here began out there. Astronomers have looked at a lot of comets trying to pin down the ratio, and what they’ve found is maddening: Some comets have a ratio very different from Earth’s, and only one (103P/Hartley 2) has a ratio similar to ours.

Now that’s interesting: 103/P is a Jupiter-family comet, meaning it used to orbit the Sun far out, but dropped into the inner solar system, got its orbit modified by Jupiter, and now has a much shorter path that keeps it in the inner solar system.

Rosetta’s comet, 67/P, is also a Jupiter-family comet. You’d expect them to have roughly similar deuterium/hydrogen ratios.

They don’t. 67/P, according to Rosetta, has three times the deuterium per hydrogen atom as Earth (and 103/P).

What does that mean? It’s not clear, which is why this is maddening. It could be simply that not all Jupiter-family comets have the same ratio; they may all have different origins (born scattered across the solar system, so with different D/H ratios), but now belong to the same family. Or it could mean that 67/P is an oddball, with a much higher ratio than most other comets like it. That would seem unlikely, though, since we’ve studied so few you wouldn’t expect an oddball to be found so easily.

Making things more complicated, some asteroids in the main belt between Mars and Jupiter have water on them, and it appears to have an Earth-like D/H ratio. But we think they have so little water that it would take a lot more of them impacting the early Earth to give us our water than it would comets. That’s possible, but we know lots of comets hit us back then, so it’s still weird that the D/H ratios don’t seem to work out. Still, it’s nice that there could be another potential source to study, and this new Rosetta result does lend credence to the idea that asteroids did the wet work.

So if you ask where Earth’s water come from, the answer is: We still don’t know. No doubt it wasn’t a single source anyway, but came from multiple kinds of objects, which muddies the water (so to speak, though kinda literally).

The good news is, we’ve only studied a dozen or so comets this way, which is a pretty small sample. As time goes on we’ll visit and observe more, and perhaps be able to nail this down better. Same with asteroids; there are a lot of them, and they’re worth poking at too.

And that’s the fun of this. Maybe no single observation will give us that “Eureka!” moment, which means we’ll just have to do more amazing, fantastic, and awe-inspiring missions to comets. What a shame.

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The Reddening of M71

Now known to be a globular star cluster at the tender age of 10 billion years, M71 is a mere 13,000 light-years away within the narrow boundaries of the faint constellation Sagitta. Close to the plane of the Milky Way galaxy in planet Earth's sky, its 10,000 or so member stars are gathered into a region about 27 light-years across near the center of this color composite view. In fact, the line-of-sight to M71 passes along the galactic plane through much intervening diffuse interstellar dust. The dust dims starlight and scatters blue light more efficiently, masking the brightness of M71's stars and shifting true star colors toward the red. How much are the star colors shifted? Slide your cursor over the image (or follow this link) to use an estimate of the dust reddening or galactic extinction to correct the star colors in M71. Corrections to the brightness and colors of M71 member stars are needed to measure the cluster's distance and age using a Color-Magnitude diagram. via NASA http://ift.tt/1IxTLtw

Twitter Highlights of Today's Stealth ISS Conference

Scimemi is talking about #NASA interest in getting away from LEO as if they are no longer interested— NASA Watch (@NASAWatch) December 10, 2014 Sam Scimemi from #NASA just said that he wants to bring casinos and gambling up...



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NASA Awards the Mid-Atlantic Regional Spaceport III Follow-On Contract

NASA has awarded a contract to the Virginia Commercial Space Flight Authority of Norfolk, Virginia for the Mid-Atlantic Regional Spaceport III (MARS III) follow-on contract.



December 10, 2014

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