Smallest rocky exoplanets: NASA spots Earth-like planets circling Barnard’s Star, but there's a catch

In a breakthrough just six light-years from home, scientists have found four rocky exoplanets circling Barnard’s Star — our solar system’s closest solitary neighbor after Alpha Centauri. These tiny, Earth-like bodies mark a milestone: despite being much smaller than Earth, they share its rocky makeup, offering a rare glimpse into the kind of planets that might lurk in our cosmic backyard.

The quartet of planets — named b, c, d and e — are some of the smallest rocky worlds ever detected. NASA says each has a mass between just 20 percent and 30 percent that of Earth, identified using the radial velocity method. This technique tracks tiny wobbles in a star’s light, caused by the gravitational pull of orbiting planets.

To spot them, scientists relied on two state-of-the-art instruments: the MAROON-X on Hawaii’s Gemini North telescope and the ESPRESSO spectrograph on the Very Large Telescope in Chile. These tools helped cut through the noise from Barnard’s Star itself, allowing the team to detect the faint signals of its planetary companions.

Barnard’s Star, a cool red dwarf, plays host to these fast-orbiting planets. The nearest one completes an orbit in just over two Earth days, while the farthest loops around in under a week. Due to their tight orbits, all four planets are likely blistering hot — far too harsh to support life as we know it.

Still, the discovery matters. “Small, rocky planets are prime targets in the search for extraterrestrial life,” said lead author Ritvik Basant of the University of Chicago. His team’s findings were published in The Astrophysical Journal Letters.