The American space agency NASA and the technology company Google have identified an eighth planet in a faraway solar system.
That solar system now has exactly the same number of planets as our own.
Machines made the surprising discovery, not human researchers.
NASA and Google representatives made a joint announcement about the discovery on December 14.
The newly discovered planet orbits the star known as Kepler-90. The system is about 2,545 light-years away. A light-year is about 9.5 trillion kilometers.
Researchers have named the planet Kepler-90i. Like Earth, Kepler-90i is the third farthest planet from its sun.
However, Kepler-90i is much closer to its sun. It only takes the planet 14 days to orbit Kepler-90. So, its surface is much warmer -- 427 degrees Celsius. In fact, all the planets in the Kepler-90 solar system orbit closer to their sun than Earth does to our sun.
So far, this is the only other eight-planet solar system that researchers have found. Eight is the largest number of planets ever observed around a single sun.
Our solar system had nine planets up until 2006, when the International Astronomical Union decided Pluto did not meet the requirements to be considered a planet. Instead, the group renamed it a dwarf planet.
But some astronomers believe there could be a large ninth planet far off in our solar system. They call it Planet X, and believe it is the size of Neptune.
Researchers also believe there could be nine or more planets in the Kepler-90 solar system.
Google used data from NASA’s special planet-hunting device, called the Kepler Space Telescope, to locate Kepler-90i.