Double Vision: Two Telescopes for Hunting Earth-like Planets

space.com ^ | 5/26/04 | Tariq Malik

[KevinDavis]

After years of whittling away prospective designs for a NASA mission to search for earth-like planets around alien stars, the space agency had narrowed the choice down to two very different observatories.

The first -- a coronagraph -- would blot out at a star's light in the hopes of seeing small orbiting planets, while the other -- an interferometer -- would use a fleet of infrared telescopes working in tandem to hunt for the same extrasolar quarry.

[KevinDavis]

Why do we need the Hubble if have these telescopes??

[KevinDavis]

Space Ping! This is the Space Ping List! Let me know if you want on or off this list!

[KevinDavis]

I meant to say, why do we need the hubble if we have these two telescopes.

[spokeshave]

Yeah.....what a hoot.they are looking for atmospheric pollution, global warming, nucear war and other indications of advanced civilization.

[CurlyDave]

Why do we need the Hubble if have these telescopes??

Trying to image planets around other stars is a very different type of astronomy than the general-purpose work the Hubble does.

Imagine looking for a planet around another star. The planet is very close to the star, and does not emit any light at all. All you see is reflected light. The star on the other hand, is extremely large and bright compared to the planet.

Think of it as looking for a gnat which is sitting on the edge of a searchlight aimed directly into your eyes from a distance of about 300 yards.

[longshadow]

I meant to say, why do we need the hubble if we have these two telescopes.

These new scopes are very "purpose-built" designs -- which is to say they do one thing very well -- look for earth-like planets around nearby stars. They aren't designed for other more general purpose astronomical observations, which Hubble excells at.

It's a bit like comparing an Indy Race car with a utility pickup truck -- the race car does ONE thing much better than the truck, but at most OTHER things the truck is a much better choice than the race car.

[NRA2BFree]

Ping!

[LiteKeeper]

read later

[spokeshave]

"read later"

In about a billion years

[El Gato]

Why do we need the Hubble if have these telescopes??

That's like asking why we need F-16s when we've got B-1s. Different missions. Hubble is to some extent a jack of all trades, but it's best at deep space work, that is extra galactic.

[El Gato]

I meant to say, why do we need the hubble if we have these two telescopes.

Forgot to add that we don't have them yet, and will probalby not have both of them ever.

[MeekOneGOP]

Bump !

[Physicist]

Because the main job of the Hubble was to measure Cepheid variable stars in cosmologically distant galaxies, which is hard to do when your telescope is designed to block out the light of the star.

[SunkenCiv]

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