TESS

Key facts

Mission & specifications

Mission

TESS, the Transiting Exoplanet Survey Satellite, is Kepler's successor, built to find planets not in one distant patch of sky but all across it, around the nearest and brightest stars. Launched on 18 April 2018, it was placed in a unique, highly elongated orbit locked in a 2:1 resonance with the Moon, which keeps it stable while giving its cameras a clear, unobstructed view. Where Kepler stared fixedly to measure how common planets are, TESS sweeps the sky sector by sector, watching the brightest stars for the telltale dips of transiting worlds. The point is proximity: planets around nearby bright stars are the ones whose atmospheres can later be studied in detail by larger telescopes such as Webb. TESS has identified thousands of candidate planets and hundreds of confirmed ones, including small rocky worlds close to home — among them TOI-700 d, an Earth-sized planet orbiting in its star's habitable zone. By cataloguing the most accessible exoplanets, TESS is drawing up the target list for the next era of the search for worlds beyond our own, and it continues to survey the sky today.

1. 2018Launch on a Falcon 9Launch

   Sets out for a unique lunar-resonant orbit to survey the whole sky for planets.

2. 2018The all-sky survey beginsMilestone

   Starts watching the brightest nearby stars, sector by sector, for transiting worlds.

3. 2018First confirmed planetMilestone

   Detects Pi Mensae c, a small world around a bright nearby star.

4. 2020An Earth-sized world in the habitable zoneMilestone

   Finds TOI-700 d, a rocky planet orbiting where liquid water could exist.

Images

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