Astronomers are a step closer to cracking one of the secrets of dark energy—the mysterious force believed to be causing the universe's accelerated expansion.

The comet is the third object ever confirmed to have entered our cosmic neighborhood from elsewhere in the galaxy. Space ...

Does Thanksgiving with the extended family make you feel like an extraterrestrial landing at the dinner table? You’re not alone. While you can’t choose your family, you can find a new one the pages of ...