A few decades ago, the Solar System had nine planets, but in 2006 the International Astronomical Union reclassified Pluto as ...

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 ...

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

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.

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 ...

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

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

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 ...