Charon is half the size of Pluto, “making it the largest known moon relative to its parent planet in our solar system,” NASA notes. So how did Pluto get its chonky companion? A new study ...

The exoplanet is also likely tidally locked to its star the same way the moon is to Earth — but perhaps its biggest eccentric ... it one of the puffiest planets known to astronomers.

The rest of us explored below, pressing forward, sounding the planet’s largest known enclosed space. Overhead the swifts chattered and bickered and called without rest, occasionally dropping ...

The fourth planet Mars will soon shine brighter than ... Mars is at its closest to Earth and therefore at its biggest and brightest. As a bonus, it will also be possible to see a rare “eclipse ...

Stars can be billions of times brighter than the planets scientists are trying to study, making them hard to see. To fix this, NASA is developing the known universe's biggest pair of sunglasses ...

Astronomers have spotted the shiniest known planet in the Milky Way ... It is so close it orbits it in just under a day. It's also very big and very hot, about 3,6oo degrees Fahrenheit, which ...