Mars is about 140 million miles from our cozy planet. A human mission to that cold, rocky neighbor would mean being away from Earth for about 3 years. But the things those explorers would see and ...

Bringing samples from Mars back to Earth is one of NASA's most ambitious goals. The plan goes back to the 1970s, with NASA's robotic exploration program, when the first spacecraft landed on the ...

There's something big missing from our solar system — and that may be a good thing. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. Planetary ...