Measuring the Masses and Diameters of the TRAPPIST-1 Planets
Jet Propulsion Laboratory https://www.jpl.nasa.gov/ Jan. 22, 2021
Measuring the mass and diameter of a planet reveals its density, which can give scientists clues about its composition. Scientists now know the density of the seven TRAPPIST-1 planets with a higher precision than any other planets in the universe, other than those in our own solar system.