Directly Imaging Earth-like Extrasolar Planets?

[misterrachel]

Will it ever be possible to directly image an extrasolar planet with enough resolution to see oceans, continents, etc...? I realize that there are a few instances already of direct imaging, but obviously without any kind of meaningful visual resolution.

If so, are there near-future plans for telescopes capable of this?

 

[MeteorWayne]

This is probably a better subject for Space Science and Astronomy, as it's not directly related to the subject of SETI.

 

[ramparts]

Absolutely not in the near future. Whether it's possible in theory... well, I'd imagine it is, in some number of decades, but I'd leave the question to the experts of whether there's something preventing that.

 

[SpaceTas]

In theory it is possible at optical to radio wavelengths using interferometers.
The best estimate of what it would take was the Terrestrial Planet Finder.
Multiple large telescopes flying in accurately controlled formation; yes decades away.

Right now we have not found any planets close enough.

 

[ZenGalacticore]

With a multi-arrayed "bug eyed" optical telescope the size of Ceres in orbit beyond the Moon, I'd bet we could visually image Earth-sized planets in our "vicinity". "Vicinity" meaning within a 50 light-year radius, give or take.

I don't know how much a telescope like that would cost, but I'd wager that it wouldn't be out of the realm of financial feasibility. Say, um, about $700 billion dollars. Which is about the current annual defense budget of the US. Oh man, the things we could see with such a glass!

 

[Couerl]

With a multi-arrayed "bug eyed" optical telescope the size of Ceres in orbit beyond the Moon, I'd bet we could visually image Earth-sized planets in our "vicinity". "Vicinity" meaning within a 50 light-year radius, give or take.

I don't know how much a telescope like that would cost, but I'd wager that it wouldn't be out of the realm of financial feasibility. Say, um, about $700 billion dollars. Which is about the current annual defense budget of the US. Oh man, the things we could see with such a glass!

That's a big one and could likely see much farther than your conservative estimate, but the Sim is much smaller (20 ft across) and could image earth-sized planets out to 30 ly's.. postponed indefinately by the fine men and women of the Govt... I'd much rather see this than any jaunt to an asteroid by humans.. "Yippee, we went to a rock"! Now what... :geek:

oops,... http://en.wikipedia.org/wiki/Space_Inte ... ry_Mission

 

[robnissen]

While pretty pictures of a planet would be nice, I'm not sure they would be that scientifically valuable and are a long way away. I'm much more interested in the ability that we currently have to detect the composition of the atmospheres of extrasolar planets and, in particular, oxygen. If we find an extrasolar planet with a relatively high oxygen content in its atmosphere, that would be strong evidence of life on that planet. Now that would be WAY COOL.

 

[SpaceTas]

The terrestrial planet finder concept was too expensive with too much new tech needed for NASA and so it has been put aside indefinitely

SIM (Space Interferometry Mission) is now SIM-Lite and won't image planets, but is designed to detect Earth mass planets, in a earth like orbit round nearby stars. This is done by measuring the position of the star and detecting its side-to-side wobble on the sky (not the back and forth wobble of the radial velocity method) as the planet orbits. Combining this with radial velocities gives a full solution for the orbit and planet mass. SIM-Lite has not yet been approved by NASA.

The presence of oceans, plants, deserts, clouds/dust can be inferred without doing imaging by measuring the polarization of the light from the planet as a function of optical/infra-red wavelength as the planet orbits. Separating the light from the planet and taking a spectrum lets you measure the atmospheric make-up and infer temperatures and pressure in the atmosphere if the spectra are good enough. Both are a long way off (10 years).

 

[ZenGalacticore]

While pretty pictures of a planet would be nice, I'm not sure they would be that scientifically valuable and are a long way away. I'm much more interested in the ability that we currently have to detect the composition of the atmospheres of extrasolar planets and, in particular, oxygen. If we find an extrasolar planet with a relatively high oxygen content in its atmosphere, that would be strong evidence of life on that planet. Now that would be WAY COOL.

On the contrary my friend. If we could actually image distant planets, especially terrestrial planets, in, um, the visual spectrum, or in any spectrum, we could learn TONS of things about what's happening on their surfaces. (And "tons" is an understatement.)

 

[ZenGalacticore]

With a multi-arrayed "bug eyed" optical telescope the size of Ceres in orbit beyond the Moon, I'd bet we could visually image Earth-sized planets in our "vicinity". "Vicinity" meaning within a 50 light-year radius, give or take.

I don't know how much a telescope like that would cost, but I'd wager that it wouldn't be out of the realm of financial feasibility. Say, um, about $700 billion dollars. Which is about the current annual defense budget of the US. Oh man, the things we could see with such a glass!

That's a big one and could likely see much farther than your conservative estimate, but the Sim is much smaller (20 ft across) and could image earth-sized planets out to 30 ly's.. postponed indefinately by the fine men and women of the Govt... I'd much rather see this than any jaunt to an asteroid by humans.. "Yippee, we went to a rock"! Now what... :geek:

oops,... http://en.wikipedia.org/wiki/Space_Inte ... ry_Mission

Santa's Hello-Helper- I always try to err on the side of conservative when discussing such future concepts.

 

[nimbus]

Found linked to on NBF blurb.
New Worlds Imager, october 2005 pdf.
Hypertelescope imaging: from exo-planets to neutron stars