Two continent-sized structures deep inside Earth may contain remnants of Theia, the ancient planet thought to have collided ...

Here's why some of the observatory's solar system pictures are ugly.

There are a couple of ways that scientists can date planets, so which planets formed first in our solar system?

Add Yahoo as a preferred source to see more of our stories on Google. Stargazers who have heard of an amazing planetary alignment coming later in January may be in for a letdown if they look up at the ...

Hundreds of Venus-like planets could soon help determine why some worlds become sweltering greenhouse hellscapes while others ...

The building blocks of rocky planets may have begun forming just 100 million years after the Big Bang—long before the first galaxies even existed—according to new research from the University of ...

A rare 6-planet alignment peaks before sunrise Aug. 12. Here's when to watch the planet parade tonight and which planets you'll actually see.

Backyard astronomers won't want to miss this special phenomena that will occur next week.

This ‘parade’ is unique because six planets (Mercury, Venus, Jupiter, Saturn, Uranus and Neptune) will align. Look toward the eastern horizon 45 to 60 minutes before sunrise and find a location with ...

A celestial phenomenon is forming in the Northern Hemisphere on Friday, as seven planets are expected to appear lined up in the night sky. Most are expected to be visible to the naked eye, though not ...

Observing the planets is one of the most awe-inspiring ways to witness the magic of the night sky—and there’s no better way to view them than in a planetary alignment. This is where multiple planets ...

Forbes contributors publish independent expert analyses and insights. An award-winning reporter writing about stargazing and the night sky. A planet parade — mistakenly called a planetary alignment by ...