Rauer, Heike; Aerts, Conny; Cabrera, Juan; Deleuil, Magali; Erikson, Anders; Gizon, Laurent; Goupil, Mariejo; Heras, Ana; Walloschek, Thomas; Lorenzo-Alvarez, Jose; Marliani, Filippo; Martin-Garcia, César; Mas-Hesse, J. Miguel; O’Rourke, Laurence; Osborn, Hugh; Pagano, Isabella; Piotto, Giampaolo; Pollacco, Don; Ragazzoni, Roberto; Ramsay, Gavin; Udry, Stéphane; Appourchaux, Thierry; Benz, Willy; Brandeker, Alexis; Güdel, Manuel; Janot-Pacheco, Eduardo; Kabath, Petr; Kjeldsen, Hans; Min, Michiel; Santos, Nuno; Smith, Alan; Suarez, Juan-Carlos; Werner, Stephanie C. “The PLATO Mission.” Experimental Astronomy 59, no. 3 (2025): 26. https://doi.org/10.1007/s10686-025-09985-9.
PLATO (which stands for PLAnetary Transits and Oscillations of stars) is a new space mission by the European Space Agency (ESA), scheduled to launch in late 2026. Its goal is to discover and study planets beyond our solar system—especially small, Earth-sized ones—as well as learn more about the stars they orbit.
PLATO is designed to find planets by watching for tiny dips in a star’s brightness when a planet passes in front of it, known as a transit. It will focus on bright stars and be able to detect planets as small as twice the size of Earth, including Earth-like planets in the habitable zone—the region around a star where conditions might be right for life.
To learn more about these planets, scientists will also collect data from Earth-based telescopes to figure out each planet’s mass, size, and age. PLATO aims to do this with very high accuracy. This detailed information will help scientists better understand how planets form and change over time, and how our solar system compares to others in the universe.
In addition to finding planets, PLATO will study the stars themselves using a technique called asteroseismology, which analyzes small vibrations in stars to learn about their internal structure. This will improve our understanding of how stars live and evolve.
The spacecraft will carry 26 small telescopes and observe the sky continuously for at least four years, making very precise measurements of starlight. This update shares the mission’s scientific goals, what kinds of stars and planets it will study, and the current progress as the instruments near completion.
Fig. 1
Planetary populations found from the accurately characterised Kepler host stars. The left panel shows the bi-modal distribution found in planetary radii ([126, 127], their Fig. 5 shown). The right panel shows the slope of the radii gap with increasing orbital period, derived using asteroseismology for improved stellar and planetary parameters ([326], their Fig. 7 shown). The cause of the gap is not completely understood but is thought to represent a break point where larger planets can retain their primordial atmospheres while the smaller objects lose their atmospheres