Science

CHEOPS

Exoplanet Characterization Space Telescope · ESA / University of Bern (Switzerland)

CHEOPS doesn't hunt for new planets — it stares at ones we've already found, and asks a single, precise question: exactly how big are you? By watching a known exoplanet cross in front of its star and measuring the star's brightness dim by a fraction of a percent, this Swiss-Swiss Airbus-built satellite, no larger than a golf cart, calculates a planet's diameter precisely enough that combined with existing mass data, scientists can finally tell whether a distant world is rock, gas, or something stranger — like an ocean world with no equivalent anywhere in our own solar system.