First Exoplanet Atmospheres Analyzed

deblau writes "NASA's Spitzer Space Telescope has captured for the first time enough light from planets outside our solar system, known as exoplanets, to identify signatures of individual molecules in their atmospheres. The landmark achievement is a significant step toward being able to detect possible life on rocky exoplanets and comes years before astronomers had anticipated."

Comments

EPA

[Tablizer]

Shit! They are all polluted also.

they can read the fine print

[User 956]

NASA's Spitzer Space Telescope has captured for the first time enough light from planets outside our solar system, known as exoplanets, to identify signatures of individual molecules in their atmospheres.

Jesus. If they can see that far out, imagine what they can see when they look straight down.

Re:they can read the fine print

[flyingsquid]

Jesus. If they can see that far out, imagine what they can see when they look straight down.

NASA says that if you don't stop doing you-know-what, you're going to go blind.

Re:they can read the fine print

[iamlucky13]

I figured somebody better follow the joke up with some clarification. The optics on Spitzer, like Hubble, aren't focused that close. Plus it's infrared. Skin complexion would look like crap.

Also, they aren't directly seeing the planet. I don't know if Spitzer's cameras could theoretically resolve it, but I do know it can't pick it out of the glare from its star. The method is to use a spectrograph and note really carefully the spectra of light received from the observation. When the planet, which is emitting light at different wavelengths depending on the molecules present, goes behind the star, this spectra changes ever so slightly. From this you know which portions of the spectra are from the star and which are from the planet, and you can deduce the molecules based on characteristic spectral lines.

This is very much like colors on an LCD monitor. Let's say you have a switch that will let you turn off one pixel of a triad (the triad being the red, green, and blue pixels that make up a visible pixel), but you don't know what color it is. If you see a yellow pixel, you know there is actually a red pixel and green pixel turned on right next to each other, even though your eye can't resolve them. You flip the switch and the visible pixel turns red, so you know the pixel you control is green. The colors of the pixels are analogous to the molecules on the planet versus the star. The pixel you can control is like the planet, but instead of a switch it goes behind the star.

Since the article apparently likes big numbers over useful units, the 370 and 904 trillion mile figures for the distances to the two observed targets are equal to 63 and 153 light years respectively.

So Our First Sign of Extraterrestrial Civilization

[Phrogman]

... will be when we discover a planet with a huge hole in its ozone layer? :P

Check their accuracy a year from now

[PDMongo]

What will be really interesting will be to see how accurate their atmospheric analysis will be a year from now. In the article they mentioned finding tiny particles of "silicates in the atmosphere". Sounds a like a lot of speculation as to what the actual data could represent.

Alien Infiltration?

[Anonymous Coward]

"The theorists' heads were spinning when they saw the data," said Dr. Jeremy Richardson of NASA's Goddard Space Flight Center, Greenbelt, Md.

Better have some xenobiologists check those guys out. Or a priest.

Re:they have to replace pluto

[gardyloo]

That newly-arrived large ominous black orb with the giant satellite dish embedded in it may qualify. Cartman became black?!?

Subtraction works

[Tablizer]

I think it is amazing how they can get the spectrum of the planet by substracting the spectrums of both using a formula like:

    planet = (star + planet) - star

In other words, take the spectrum of both and compare it to the spectrum of the star when the planet is behind the star.

It seems to me the star's spectra would be so strong as to wash out anything from the planet. However, maybe the specific chemical signatures they are looking for are weak in the star. For example, stars are probably too hot for a water line. Water would probably be converted into fundimental elements by the star.

Re:Subtraction works

[1fitz2many]

These data were taken in the mid-infrared, where the contrast between the star and the planet is not as great --- only about 200--300:1, instead of 10^6--10^10 to 1 in the optical/near-IR.

Re:I for one

[Original Replica]

Our exoplanetary overlords don't want our water. What would a sentient cloud of silicon crystals want with H2O? They are just trying to figure out if the silicon chips of our planet are willing to sell a few of their pet waterbags. (that's us)

Not earth like

[rossdee]

All the extra solar planets that have been found so far are large gas giant type planets.

Our telescopes aren't good enough (yet) to detect small earth size rocky planets.

While spectographic analysis of these planets atmosphere is interesting, it does not give us information about the possiblity of life (as we know it, Jim) since these aren't the places we would find life in this solar system either. Maybe these other planetary systems do include rocky planets, or moons (like titan and europa ) that could be candidates for some form of life, but we wouldn't find that out by looking at the atmospheres of JUpiter and Saturn

Re:Not earth like

[1fitz2many]

There have been some recent discoveries of some "super-Earth" planets, e.g. GJ 876d and a planet found through gravitational microlensing, that have masses several times that of Earth. In the core-accretion scenario for planet formation, it's hard to stop runaway gas accretion once it gets going, suggesting that such low-mass planets are rocky and not gaseous. Perhaps they're the remnant cores of former gas giants that have lost their gaseous envelopes via some process that occurred after formation.

Re:However, due to lack of federal support

[MightyMartian]

That's not NASA's fault. That's the fault of greedy, whorish, self-serving Congressmen who, in place of a sense of vision and wonder, hold their proverbial genitals in their hands making idiotic demands upon the agency before they'll vote on funding. The ISS that was originally proposed would have been quite something. A space shuttle that actually followed the initial requirements would have been incredible. But by the time it was all filtered through the worthless filth that inhabits Washington, we were left with a pack of crap.

Maybe they're using the Smelloscope

[Dachannien]

Professor Farnsworth: Now, we all know telescopes allow us to see distant objects. But what if we want to smell distant objects? Well, now we can! Thanks to my new invention: the Smelloscope. The odor travels past this coffee stain here, around the olive pit, and into this cigar burn. And this appears to be a doodle of myself as a cowboy. But the Smelloscope is brilliant, I tell you! Think of the astronomical odors you'll smell, thanks to me.

Re:Not the First, Folks

[Seanasy]

If you RTA, they mention that Hubble was only able to identify elements in the atmosphere and was using a different technique. Spitzer is able to make out molecules.

Re:So Our First Sign of Extraterrestrial Civilizat

[David Jao]

I think we'd be more amazed to discover a planet with an ozone layer, period.

This is more true than probably most slashdotters realize. Ozone is the only chemical indicator of life that we can reliably detect across long distances.

Ozone, unlike oxygen itself, has a strong absorption spectrum in the infrared wavelengths. A space-based infrared telescope (like Spitzer, but better) is exactly the right tool for detecting the presence of ozone. (A ground based telescope will not do, since infrared is absorbed by the atmosphere.) Finding ozone on a planet is just like finding oxygen -- the two compounds are so closely related that you can't have one without the other. And oxygen is a very volatile compound that reacts with almost anything else if you leave it alone. The only way for a planet to have free floating oxygen is if something on the planet is producing it.

As far as we know, the only way to sustain an oxygen atmosphere on a planetary scale is with life. So, yes, finding ozone on a distant planet would be a very exciting discovery indeed.