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 ...

Venus and Saturn are currently in conjunction, meaning the planets appear close together in the night sky from Earth. These ...

Planetary alignments aren't rare, but they can be when they involve six of the eight planets in our solar system.

A parade of planets will be visible to skywatchers around the globe through the rest of this month and into February.

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 ...