Even more amazing, machines and not humans made the discovery. NASA joined with Google on Thursday to announce the finding.
This eighth planet orbits the star known as Kepler-90, 2,545 light-years away. Like Earth, this new planet is the third rock from its sun. But it's much closer to its sun and therefore a scorching 800 degrees Fahrenheit (427 Celsius) at the surface.
Google used data collected by NASA's exoplanet-hunter, the Kepler Space Telescope, to develop its machine-learning computer program. It focuses on weak planetary signals - so feeble and numerous it would take humans ages to examine.
This is the only eight-planet solar system found like ours - so far.