Future telescopes to study exoplanets?

[Oli]

It honestly doesn't matter; even if we had perfect spectra of a terrestrial planet, we'd still struggle to figure what was (and wasn't) a signature of life.

Well, biomarkers (e.g. oxygen, ozone, nitrous oxide) in the foreseen concentrations would be an indicator of life, not a proof. Exciting enough for me.

And if we do detect something, noone will believe a signature from a terrestrial telescope; the preceise things we would be looking for are also the bands that the telescope has to look through in Earth's atmosphere.

Source?

[grondilu]

But first you would need to detect the Earth-sized exoplanets orbiting the nearest Sun-like stars. TESS may detect the transiting ones, but the geometric probability for transits is not very high for planets in the habitable zone of Sun-like stars, thus you would not detect most of them with TESS. An astrometrical search with a precision of sub μas could find all these planets for the nearest Sun-like stars. SIM lite is/was such a project. In Europe there is a proposal for a mission called NEAT (Nearby Earth Astrometric Telescope) with 0.05 μas precision. It would search the 200 nearest Sun-like stars for Earth-sized planets. For more information please see http://neat.obs.ujf-grenoble.fr/NEAT.html .

Let's not forget the Gaia astrometric mission, which is very exciting and should be launched in just a few months.  It should discover thousands of exoplanets (not sure if it could detect earth-size planets, though).

Again, this does not really answer OP's question but really before one should try to study exoplanets, we definitely need to detect as many of them as possible, imho.

[Oli]

And what capability would JWST offer in this area?

To my knowledge upcoming ground-based telescopes have a spatial and spectral resolution several times higher, so I guess directly imaging exoplanets is not a particular strength of JWST, but it will shine in other areas of course.

[Vahe231991]

Sorry to revive a long dead thread, but the James Webb Space Telescope recently spotted an exoplanet for the first time:
https://www.nasa.gov/feature/goddard/2023/nasa-s-webb-confirms-its-first-exoplanet

According to observations from JWST, the exoplanet with designation LHS 475 b is almost exactly the same size as Earth, although further study is needed to determine if it has an Earth-like atmosphere.

There is also a link from May 2022 describing a new conceptual imaging technique to allow space telescopes to get better images of the surface of an exoplanet:
https://news.stanford.edu/press-releases/2022/05/02/gravity-telescope-image-exoplanets/

[JulesVerneATV]

NASA's Hubble Observes Exoplanet Atmosphere Changing Over 3 Years
https://hubblesite.org/contents/news-releases/2024/news-2024-003

Some future missions, China will have their own Hubble next to a Space station, PLATO (spacecraft) an ESA mission in 2026? Nancy Grace Roman Space Telescope Wide IR NASA Goddard in 2027? post JWST Large UV, several versions for the LUVOIR telescope. Other giant sized ground based telescopes using adaptive optics.

[jebbo]

Also HabEx (with a distant sunshade) around 2035, aiming to directly image planets around Sun-like stars. This will be followed by the Habitable Worlds Observatory.

--- Tony

[LMT]

There's the "lunar hypertelescope" concept, too.  Artemis might open an opportunity there.

Image:  prototype Southern Alps hypertelescope design from hypertelescope.org

[Joris]

https://www.nature.com/articles/s41598-023-39972-z

Other possible technosignatures could be hydrofluorocarbons, perfluorocarbons, chlorofluorocarbons, hydrochlorofluorocarbons and halons. Fluorinated greenhouse gasses in general are strong indications of technosignatures, but that is arguably a more rare thing to search for than signs of life itself. More interesting to find a technosignature than just life though IMO.

[LMT]

There's the "lunar hypertelescope" concept, too.  Artemis might open an opportunity there.

Image:  prototype Southern Alps hypertelescope design from hypertelescope.org

NIAC is now open to Artemis deployment of such imagers.  2024 Phase I selection:

"A Lunar Long-Baseline Optical Imaging Interferometer: Artemis-enabled Stellar Imager (AeSI)"

h/t Asteroza