The Solar System is home to a remarkable range of planets, from tiny rocky worlds to massive gas giants. But just how big are these planets really? To put it into perspective, we can run some ...

Look to the east slightly ahead of dawn on Sept. 2 to catch a fleeting glimpse of fleet-footed Mercury alongside the bright star Regulus, before it becomes lost in the light of the rising sun. Want to ...

The fall equinox is a significant event in any tipped planet's life. Seasons are caused by a planet's tilted axis. Those which orbit the sun standing nearly straight up and down with little to no ...

From Newton’s falling apple to Einstein’s curved spacetime, our understanding of gravity has come a long way, yet this ...

Early risers are in for a spectacular show next week, when Jupiter, Venus and Mercury form a planetary lineup in the predawn sky on Sept. 1.

Did you miss the planetary parade? Well, Thursday, Aug. 21, is the last day to see it, along with the crescent moon. Usually, people can look up at the bright sky and spot at least one planet. Two or ...

How do you tell how old an astronomical object is? I mean, the next time the moon is in the sky, take a look at it. How would you even begin to answer that question? I won't leave you in suspense.