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

A six-planet alignment or parade will form an arc in the early night sky, peaking in it's visibility Jan. 17-18. We let you ...

Growing up, I was taught that there were nine planets in the solar system. That all changed in 2006, when the International Astronomical Union voted to demote Pluto’s status to that of dwarf planet.

A powerful new tool comes online this year that could help astronomers locate the mysterious planet hiding somewhere beyond ...

Unless you’re really on the low end of our listener age bell curve, chances are you grew up learning about our solar system’s nine planets. Of course, unless you’ve been living under a rock ...

NASA's Director of Planetary Science, Jim Green, discusses the Jan. 20 2016 Astronomical Journal science paper that points to ...

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

A planet parade like the one beginning tonight is quite uncommon, occurring once every 10-20 years. Here are the planets you ...

Sky gazers will get a peek at what has been called a "parade of planets," where this time around, up to seven planets may ...

17 and 18. Timing: Dusk after sunset, but before 9 p.m. local time There are eight planets in our solar system and one dwarf planet (Pluto). Because we live on Earth, the most we could see is a ...