An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit ...

Research by astronomers, led by the University of Geneva (UNIGE), challenges current theories about the formation of ...

The discovery of an extraordinary multi-planet system has demonstrated that so-called "hot Jupiter" planets may not be lonely ...

Because the period of an object does not depend on its mass, comets’ orbital periods remain unchanged due to mass loss.

Pluto may have got romantic to capture its largest moon, colliding and engaging in a passionate but icy 10 hour kiss with ...

Compared with Earth ... Mars inside which gravitational tidal forces from the planet become too great and tear apart any interloping body. The distance of the Roche limit varies depending on the ...

“Planets have different motions in the sky. They move at different rates compared to the other stars ... There are eight planets in the solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, ...

Two significant additional discoveries-the identification of twin water worlds, Kepler-138c and d, and the existence of water ...

Alignments of five or more planets are rare—there will be two more featuring five or more planets this year, but after that ...

All month, four planets — Venus, Saturn, Jupiter ... from Earth's perspective, NASA said. (Though in reality, there are hundreds of millions of miles between them.) Meanwhile, Mars is at ...

Over the next few weeks, a stunning parade of planets will glow across the night sky, putting on a celestial spectacle that both amateur and seasoned stargazers can easily observe. All month, four ...