23 Oct 2019
There are millions of asteroids in our solar system. Because some are full of materials that are rare on Earth, they have been valued at stupendous amounts. But the most valuable resource in space may be something that's abundant back on the ground.
28 Oct 2017
A small asteroid or comet that has been spotted racing through our solar system may have come from elsewhere in the galaxy, U.S. space scientists say, possibly marking the first such interstellar visitor observed from Earth.