Nicole L. Wallack

The super-hot super-Earth TOI-561 b completes an orbit around its star in just 10.7 hours. It is a scorched rocky sphere, so close to its star that its dayside should heat up to 2950 K, a temperature at which many minerals melt.

130 light-years away, four giant planets orbit the young star HR 8799—each 5 to 10 times more massive than Jupiter. They lie far from the star, at distances from 15 to 70 astronomical units (one astronomical unit is the distance from Earth to the Sun).

In 2024, the team led by David Charbonneau pointed the Magellan telescope with the WINERED spectrograph at LHS 1140. During transit, high-resolution spectroscopy caught the absorption line of metastable helium at 10833 Å.

Deep inside a sub-Neptune, where pressures reach a hundred thousand bars and temperatures hit four thousand degrees, rock behaves like boiling soup. Heavy vapors of silicon and magnesium rise, cool, and fall back as a rain of solid particles.

A balloon someone forgot to tie off deflates before your eyes. That is roughly how GJ 3090b behaves: its hydrogen-helium envelope is leaking into space at a rate that surprised astronomers. The planet is only twice the size of Earth, yet it is shedding gas as if it wanted to get rid of everything superfluous as fast as possible.