NASA's Roman mission could discover 400 Earth-mass rogue planets

A new study by NASA and Osaka University suggests that there are far more rogue planets, which drift through space without orbiting a star, than planets that orbit stars. The study estimates that there could be trillions of rogue planets in our galaxy, with the potential for NASA's upcoming Roman Space Telescope to discover around 400 Earth-mass rogue worlds. The research is based on a nine-year survey using microlensing observations, which revealed the second discovery of an Earth-mass rogue planet. The findings also indicate that Earth-size rogue planets are more common than larger ones, providing insights into planetary formation mechanisms. The Roman Space Telescope, set to launch by May 2027, will significantly expand the search for these hidden worlds.