Huge telescopes could spy alien oxygen

[Judi Lynn]

Huge telescopes could spy alien oxygen
16:44 19 February 2013 by Jacob Aron
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Giant telescopes like the Extremely Large Telescope now being built in Chile could hunt for alien life by detecting oxygen on exoplanets – even though they were not designed with that in mind.

On Earth, plants and some bacteria are the only sources of large amounts of atmospheric oxygen. Finding oxygen on an exoplanet would therefore be a tantalising hint of life as we know it.

Current telescopes can look at the light that passes through exoplanet atmospheres and tease out their make-up, based on the substances that absorb particular wavelength bands. "We do this now for Jupiter-sized planets," says Ignas Snellen of Leiden Observatory in the Netherlands.

But current telescopes are not sensitive enough to see atmospheres on small, rocky worlds. What's more, observations made from the ground struggle to filter out Earth's own oxygen-rich atmosphere. Space missions intended to hunt for distant oxygen have been cancelled.

More:
http://www.newscientist.com/article/dn23193-huge-telescopes-could-spy-alien-oxygen.html?cmpid=RSS|NSNS|2012-GLOBAL|online-news

[longship]

1. And a 39 meter diameter mirror!

That's about 128 feet. It's going to be a real monster.

[Neoma]

2. More than 7 years of bad luck if you break that thing.

[longship]

3. But you have to climb high in the Chilean Andes to get at it.

Better take drinking water; the Atacama desert is about the driest place on the planet. Senator Rubio would never make it alive.

[Neoma]

4. Does it do anything else besides being dry?

[longship]

5. Well humidity degrades visual astronomy.

Also, it helps if you have less atmosphere to look through. That's why they build those things on mountaintops. The ELT is going to be at about 9,850 ft.

Other observatories are above 13,000 feet, in Hawaii, and another in Chile. The less air you look through the clearer the image. Plus, the mirrors change shape thousands of times a second to cancel atmospheric distortion. You don't want the stars to twinkle. That's bad.

But breathing up there can be difficult. They have control rooms at lower elevations.

[Neoma]

6. Ah.

When I think of mountains I think of the smokey mountains and how unpredictable the weather is. Though, there would be a good reason not to have one there anyways. Humidity kills there.

[longship]

7. Ah! But the Smokeys are beautious!

I drove through them in the late 60's on the way to Florida for vacation and had to spend a couple of days camping there just to take it in. But it would be a bad place to put a telescope. Camping was good, though.

[Neoma]

8. They're more smokey now...

But yeah, I grew up camping there a lot. Went to the bluegrass festivals a lot.