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May 25, 2005
Will the Terrestrial Planet Finder Be Successful in Finding Other Worlds?
You may not have marked it on your personal calendar yet, but NASA’s Terrestrial Planet Finder (TPF) will be launched in the next 10-15 years. Two telescopes, to be launched in 2014 and 2020, will change the way we view the universe, literally and figuratively. As its name implies, TPF's job is to find Earth-size worlds around other stars. Full disclosure compels me to point out that the TPF won’t be the first opportunity we’ll have to actually discover planets the size of our own: NASA’s Kepler mission, which will be hefted off the launch pad in June, 2008, will be able to do that. But Kepler will not actually see those planets. Instead, it will look for the slight, periodic dimming of stars caused by planetary eclipses. If you happened to catch the transit of Venus last year, you get the idea. For six hours, Venus moved as a small, dark dot across the Sun’s incandescent epidermis. If you looked at this event from many light-years away, using the Kepler telescope, all you would have noted was that starlight from the Sun was diminished by 0.01 percent for six hours. But that would have been enough to tell you of Venus’s presence and size. Kepler will reveal to us other “Earths,” and how common they are.
But the TPF, unlike your 1987 Yugo, will go farther. The first telescope to be launched will be a single-mirror instrument, with a device to block out the light from stars—kind of like a mechanical thumb— in order to see the much dimmer planets that might be in orbit around them. The second TPF, scheduled for lift-off in 2020, will operate at
A second function of the TPF is to follow up on these planetary discoveries by taking apart the light from a newfound planet. On-board spectroscopes will accomplish this spectral slice-and-dice, allowing astronomers back on Earth to hunt for absorption features that can be used to fingerprint gasses in the planet’s atmosphere. They’ll be looking for the tell-tale signs of large-scale biota. For example ozone, which is just oxygen, would signal the presence of photosynthesis (or something like it). Methane is another gas that’s common in our own atmosphere because of pigs, cows, and bacteria (not necessarily in that order). Finding it in the atmosphere of another world might be big news -- not just because of the dining possibilities. The TPF is coming and so are big discoveries, so mark your calendars.
Posted by Seth Shostak on May 25, 2005 10:23 AM
Visit the Planetary Investigation Lab to see the creatures and worlds explored in the show. Go »
Comments
I've read the whole story. That's outstanding project. I think when accomplished it will be like the invention of the first telescope by Galileo. It will allow us to see another planetary systems!!! Such a huge leap. It will answer many questions the humanity dreams to answer, but at the same time it will yield a lot of new questions, that makes my blood flow faster.
Posted by: Erdem on June 6, 2005 04:58 AM
Have you heard anything recent on the whole notion of using a gigantic pinhole camera for high-resolution imaging of extrasolar planets?
And how much of a jump is it between seeing a point of light and resolving a disk? I mean we weren't able to resolve anything super-useful on Pluto until Hubble, but that's a straightforward single mirror, versus some sort of super-clever optical interferometery or something.
Posted by: BravoRomeoDelta on May 30, 2005 11:26 PM
Just an overall of the site:
Everything seems really organized, which is nice, but I'm a highschool student looking for a particular article and I cannot find it anywhere. It'd be nice if there was a way or a place that I could do that without buying the issue. I'd like to hope that there is a place that this can be done and that I'm simply overlooking it because it is such a simple, useful resource to have.
Posted by: Pandora on May 26, 2005 01:39 AM
I'm pretty excited about this as well. I'm really looking forward to hearing what it finds.
Posted by: Keith on May 25, 2005 08:23 PM
This is what I look forward to the most... Except of course the prospect of contacting alien life in my life time!
Posted by: KennyJC on May 25, 2005 07:43 PM
