Clyde Tombaugh discovered Pluto in 1930 at Lowell Observatory in Flagstaff. Here's how Pluto won - and lost - its planetary status.

Why is Pluto no longer a planet? Discover the real reason behind Pluto’s reclassification as a dwarf planet and the science that led to this change.

According to a recent YouGov poll, 35% of Americans think Pluto is not a planet. But they are all wrong—kind of. To get to the bottom of whether Pluto is a planet, I tracked down planetary scientist ...

On today’s date 95 years ago, everyone’s favorite not-quite-a-planet, Pluto, was discovered by astronomer Clyde W. Tombaugh ...

What is happening in Earth's inner core? Discover the implications of its deformation for seismic activity and navigation.

These popular astronomy questions, answered by Astronomy magazine, will help you better understand our universe - and share ...

Explore Ceres, the largest asteroid in our solar system, and discover its remarkable ancient ocean and ice-rich crust.

The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

“You just pick if you want to be on Pluto, Mars or the Moon,” Zima said as she demonstrated a fun activity called Gravity Jump. Folks can take a leap and see the gravity in space versus the ...

The capsule rotated mid-flight to replicate Moon gravity for research payloads ... A new study suggests Pluto's largest moon, Charon, may have formed through a unique "kiss and capture" event ...