If Planet 9 is real, this observatory has around a 70 to 80 percent chance of finding it, he estimates, adding that it's not a sure thing because there are so many uncertainties.

Researchers at Cambridge University's Institute of Astronomy believe that there is a 99.7% chance of life on K2-18b, a large planet located 700 trillion miles from Earth ...

Scientists find "strongest evidence yet" of life in space 01:04. Astronomers announced Thursday that they had detected the most promising "hints" of potential life on a planet beyond our solar ...

Scientists at the Institute for Advanced Study in Princeton, New Jersey, discover a new trans-Neptune Object, 2017OF201, potentially discrediting 2016 theory of Planet Nine.

The hunt for Planet Nine—the solar system’s ghostly gravitational troll—is longstanding, and is based on the peculiar clustering of rocky bodies in the Kuiper Belt beyond the orbit of Neptune.

Astronomer breaks down "strongest evidence yet" of life on distant planet 04:06. Astronomers announced Wednesday they have discovered a massive planet orbiting a tiny star, a bizarre pairing that ...

Pluto was discovered in 1930 in Arizona, but in 2006 scientists decided to cut Pluto from the planetary line up. Here is why Pluto isn't a planet.