Astrophysicists have long theorized that there should be planets out there that are, in size, somewhere between Earth and ...

Data collected from a once-defunct NASA satellite show that Earth grew two extra radiation belts following a supercharged ...

These are known as hypervelocity stars, with some moving faster than the escape velocity of the Milky Way of around 600 kilometers (373 miles) per second. There is another star that is almost as ...