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.

An amateur astronomer discovered Pluto 95 years ago today. The former planet will complete an orbit in another 153 years.

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

“Pluto and Charon are different—they’re ... celestial bodies as collections of particles that can interact through gravity and physical contact. They ran multiple simulations varying factors ...

To get somewhere in outer space, you can’t exactly drive in a straight line. Orbits are tricky things, and sending a probe to ...

For the first time, astronomers have imaged dozens of belts around nearby stars where comets and tiny pebbles within them are ...

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

Their interactions allow us to measure whether the pulsar and inner white dwarf respond to the more distant dwarf’s gravity identically ... in the mass gap between Pluto and Mercury, it could ...