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

And we can't rule out additional planets in the system either." A comparison between the exoplanets of Kepler-51 and the Solar System ... the Kepler-51 system. One way to do that will be to ...

Accessible to anyone the world over, witnessing the majesty of the solar system, including the Milky Way, and its billions of ...

Related: White dwarfs are 'heavy metal' zombie stars endlessly cannibalizing their dead planetary systems "It's the only bona fide way to actually figure out what planets outside the solar system ...

Learn about the size, temperature, and colour of each planet, and discover why Pluto is no longer considered a planet.

The newcomer replacing Pluto presently goes by “Planet Nine.” If and when it finally shows up, it will get the honor of a ...

Astronomers have spotted the shiniest known planet in the Milky Way, and it has metal ... only bounces back 30% of its sunlight. Venus, the solar system's shiniest planet, reflects 75% of the ...

The planets in the Solar System are all different but we can divide ... which is called the Milky Way. The Milky Way is a spiral galaxy and our Solar System is about half-way along one of its ...

A rare parade of planets will light up the night sky throughout January. Six planets will be in alignment for the rest of the ...

This composite of planets in our solar system was taken by various NASA spacecraft. Included in the image are (from top to bottom) Jupiter, Saturn, Uranus, and Neptune. Credit: NASA/JPL.

Milky Way May Have Billions of Earth-Like Planets There could be as many as 40 billion habitable Earth-size planets in the galaxy, according to a new study. WSJ's Monika Vosough reports.