An alternate explanation that fits the evidence is that Vesta was once part of a planet – but which planet that might been ...

Discovered in 1930, Pluto was long considered our Solar System's ninth planet, but was unseated in 2006 after the discovery ...

Researchers say they found a curious dot on infrared images taken 23 years apart that seems to be moving in a manner consistent with a large, distant planet.

The Hubble Space Telescope time-lapse captured footage of Jupiter, Saturn, Uranus and Neptune. Credit: SCIENCE: NASA, ESA, ...

"I had been waiting my entire career for Webb so that we could meaningfully characterize the atmospheres of these smaller ...

Astronomer Eliza Kempton said that she had waited her "entire career" to peer into an atmosphere from this mysterious class of planets.

For years, astronomers have toyed with the idea that the Sun hides an extra planet so distant and dim that even the best ...