When Earth is opposite Mars from the sun, it will appear full because you’re looking directly on the daylit side. But ...

Mars and Earth, two neighboring planets, have captivated the human imagination for centuries. Often hailed as Earth’s “sister planet,” Mars holds a special place in the study of our solar system. But ...

A new review of ocean data suggests that more than 99.999 percent of the global deep seafloor has never been seen by humans. But what does that really mean? “In scientific papers, some people [said] ...

Because oxygen-bearing sulfate minerals trap and preserve signals from Earth's atmosphere, scientists closely study how they ...

New simulations suggest that up to four of the solar system's rocky planets, including Earth and a long-lost world, once orbited in mathematical harmony around the infant sun. Four of the solar system ...

The largest piece of Mars ever found on Earth was sold for just over $5 million at an auction of rare geological and archaeological objects in New York on Wednesday. But a rare young dinosaur skeleton ...

No human has been to the planet of Mars, but a very wealthy individual will be able to come close after purchasing a massive chunk of the planet at an exclusive auction. The largest piece of Mars ever ...