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 ...

Astronomers have captured the clearest picture yet of how massive stars are born, revealing a dramatic interplay between ...

Astronomers have taken their clearest look yet at how some of the biggest stars in our galaxy are born—and it turns out the ...

An astronomer's animation reveals how far the average person could throw a ball on different worlds. On Pluto, your baseball could clear the Great Pyramid of Giza. On Jupiter, it plops to the ground.

Pluto isn’t considered a planet because it lacks enough gravity to clear its orbit, not just because of its distance. Despite receiving less than 1% of Earth’s sunlight, Pluto is still surprisingly ...

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 ...

Astronomers using the Hubble Space Telescope have observed a white dwarf - a highly compact stellar ember - that appears to have gobbled up an icy world akin to the dwarf planet Pluto, a finding with ...

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 ...

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 ...

In a post yesterday, I talked about the Moon orbiting the Earth, and the Earth's gravitational sphere of influence, called its Hill sphere. If you have an object orbiting the Sun (like a planet, say), ...