Long ago, a planetary object eight times the mass of Jupiter may have once visited the solar system and altered the orbits of the four outer planets-Jupiter, Saturn, Uranus, and Neptune.

Astronomers have spotted four smaller-than-Earth ... we can confidently rule out any planets more massive than 40 to 60 percent of Earth's mass near the inner and outer edges of the habitable ...

An artist’s conception of the view from one of the four planets orbiting Barnard’s Star. Illustration by R. Proctor/J. Pollard/NOIRLab. Astronomers have revealed new evidence that there are ...

Scientists have discovered four new ... study The planets revolve around Barnard's Star in closely grouped radii. The inner planet takes more than two days to orbit, and the outer planet seven ...