In late August 2006, new discoveries upended a traditional, comfortable way of viewing our solar system: Scientists decided Pluto wasn’t a planet after all. Some space nerds like to mourn Pluto’s loss ...

Simulation of the moon Nix which orbits Pluto every 25 days. Here that's sped up to one orbit every two seconds, so we can see its chaotic spin more clearly. Little moons in the solar system have it ...

What will our solar system look like after the Sun dies? This is what a recent study published in the Monthly Notices of the Royal Astronomical Society hopes to address as a team of scientists ...

Watch a ball throw on each planet in our solar system, plus Pluto and the moon, below. Imagine throwing a baseball. Easy, right? Maybe you've already done it a few times. Now imagine throwing a ...

On Aug. 24, 2006, the International Astronomical Union voted to strictly define a planet, which ultimately downgraded Pluto from the ninth planet from the sun to a dwarf planet — causing controversy ...

This one comes from SnowGhost's question about the lack of impact craters on Pluto and allowed me to use one of the most unlikely titles you're ever going to see in the physical sciences. Pluto is not ...

In a few billion years, our Sun will become so violently hot that it could wipe out all life in the Milky Way. Yet, ...

When NASA first considered a mission to Pluto more than 15 years ago, the idea was to visit the last and most distant of the nine planets, an oddball whose icy composition, tilted orbit and tiny size ...

The methane gas may constitute a rarefied atmosphere, or it may come from erupting plumes on Makemake’s surface.

The definition of a planet has been a hot topic ever since a change kicked Pluto out of our planetary lineup in 2006. Now, a group of researchers is proposing a new definition yet again—one with much ...

For decades, our solar system was thought to have nine planets, with Pluto considered the smallest and farthest. But in 2006, Pluto was officially reclassified as a dwarf planet by the International ...