Planet 9 is the hypothetical ninth planet in our Solar System. Has it finally been found using IRAS and AKARI mission data?

Astronomers have discovered icy rocks in the outer solar system that seem to defy the laws of physics, raising questions ...

There are eight known planets in the solar system: Earth, Mars, Uranus, Neptune, Pluto, Saturn, Venus, Mercury, and Jupiter. However, some scientists believe that there is a ninth planet hiding among ...

Add Yahoo as a preferred source to see more of our stories on Google. Planet Nine is a theoretical planet in the outer solar system that has proved to be extremely hard to find. | Credit: Shutterstock ...

Chapters: 0:00 Why planet 9? 1:30 How did we determine that Planet 9 may exist? 4:30 Why haven't we seen Planet 9? 6:06 ...

Astronomers believe there is a Planet Nine in the outer solar system beyond Neptune. A team led by Amos Chen from the National Tsing Hua University, is searching for Planet Nine’s heat signature. When ...

There may be a warp in the Kuiper Belt, possibly caused by “Planet Y” — a Mercury-to-Earth-sized world that orbits the sun way beyond the orbit of Neptune. Is there a mysterious “Planet Y” orbiting ...

Mike Brown is convinced that beyond Neptune, at the far reaches of our solar system, there's an unseen giant planet. "This is the 5th largest planet in our solar system, lurking out there, waiting to ...