The Telescopes Actually Finding and Studying Exoplanets Right Now

Exoplanet Science Relay

Exoplanet science runs on a relay: no single instrument does the whole job. Different telescopes are built for different stages. This is a step-by-step process: finding a planet, confirming it's real, weighing it, and eventually reading its atmosphere.

TESS (Transiting Exoplanet Survey Satellite)

TESS is the finder. Launched in 2018, it surveys nearly the whole sky in overlapping strips, watching for the tiny dip in a star's brightness as a planet passes in front of it. It's designed specifically to catch planets around bright, nearby stars, because those are the ones worth a closer look later. TESS has already found the majority of transiting planets smaller than Neptune that have gone on to be studied by JWST, essentially acting as a finderscope for everything that comes after it.

Keck Observatory

Keck doesn't find planets, it confirms and weighs them. Once TESS flags a candidate, Keck's HIRES instrument measures the star's radial velocity, the subtle Doppler wobble caused by an orbiting planet's gravity, which is what actually yields a planet's mass. A TESS detection alone tells you a planet's size; you need Keck (or an instrument like it) to know what it's made of. The two instruments work together often enough that there's a formal joint effort behind it, the TESS-Keck Survey, which has confirmed masses for well over a hundred planets.

On Rakiura, Limits of Habitability runs an open community project, TESS-Keck Survey Data Validation, checking and validating candidate detections from exactly this survey.

This project walks contributors through the actual screening pipeline: pulling SPOC transit results from the TESS database, checking candidates against other teams' follow-up targets so no one's duplicating work, then screening for hidden stellar binaries using MAST and high-resolution Keck spectra.

JWST (James Webb Space Telescope)

JWST is where characterization actually happens. Once a planet is found and its mass is known, JWST can perform spectroscopy on its atmosphere, splitting starlight that's passed through the planet's air into a spectrum and reading the chemical fingerprints inside it: water, carbon, and other molecules relevant to habitability. TESS was explicitly designed with this handoff in mind, built to surface the brightest, most favorable targets specifically so JWST's limited observing time gets spent well.

Project Starshade

Everything above relies on an indirect signal produced by a planet transiting its star or tugging on it. Project Starshade, led by MIT astrophysicist Sara Seager, is aimed at the much harder problem of seeing a planet directly: a giant flower-shaped screen flown in formation with a space telescope, designed to block a star's glare precisely enough to image an Earth-like planet on its own.

Direct imaging remains rare; there are more than 6,200 exoplanets discovered to date, and under 100 planets have ever been found this way, precisely because blocking out a star well enough to see a much fainter planet next to it is an extraordinarily hard engineering problem.

On Rakiura, Project Starshade runs its own open community project, the Starshade Science Case, working through the science case for the mission directly.

The output is a prioritized, scientifically reasoned target catalog that the researchers can cite, present, and publish, exactly the kind of rigorous, public case NASA's funding decisions run on.

NASA's Roman Space Telescope

Launched on August 30, 2026, Roman is about to change the scale of everything upstream of JWST. It's expected to find more than 1,000 planets via gravitational microlensing and around 100,000 more via the transit method, surveying a dense region toward the galactic bulge that no previous mission has looked at this closely. This will feed the whole relay, TESS, Keck, JWST, and eventually Starshade-style direct imaging, with far more targets than exist today.