News Astronomy

Two exoplanet families redefine what planetary systems can look like

The planet densities and orbits at TRAPPIST-1 and TOI-178 buck astronomers’ expectations

Illustration of TOI-178 system

Astronomers expect dense planets to lie close to a star and fluffy planets farther away. But TOI-178’s six worlds, shown in this artist’s illustration, are all jumbled up.

ESA

By Lisa Grossman

- More than 2 years ago

Two tightly packed families of exoplanets are pushing the boundaries of what a planetary system can look like.