Telescopes and Exoplanet Atmospheres Options

[StargazeInWonder]

This is a really nice overview of what the next decade or two might permit in terms of studying the atmospheres of candidate "earthlike" planets.

http://surveygizmoresponseuploads.s3.amazo...lesMercedes.pdf

Some key points:

• There are about 2 or 3 terrestrial transiting planets that JWST will be able to study, and probably no more. (TRAPPIST-1 d and e.) The signal integration time is just too great and the HZ of nearby M dwarfs cannot be resolved by JWST in IR, even for Proxima b.

• There is an expected crop of about 5-10 TESS candidate earthlike discoveries (which we're still waiting for, since only one has been confirmed so far).

• About 5-10 candidate earthlike non-transiting planets in the HZ of nearby M dwarfs can be resolved and studied by ELT, GMT, etc. when they begin operation.

• ELT and GMT can potentially resolve and study any terrestrial planets in the HZ of about 10 nearby sunlike (A-K) stars. So far, zero or one such planets have been found (Tau Ceti e). Other research gives an expectation that the total number of planets in this category is roughly 2.

• Summing up, about 10-20 terrestrial planets in their stars' HZs may have their atmospheric compositions studied over the next 20 years. There are lots of constraints, though. Some relevant gases will be relatively easier or harder to detect, and planet-specific factors (global cloud cover, for example) may ruin our efforts to study one planet or another.

Now we just have to wait for the telescopes to come online and start making observations.