A 54-pound (25-kilogram) rock. Estimated auction price: $2 million to $4 million. Why so expensive? It’s the largest piece of ...

Mars isn’t a bright, fire-engine red, but the iron oxide in its rocks makes it appear redder than other planets, especially from afar.

So in a way, the ancient connection between the planet Mars and blood wasn’t completely wrong. Rust, which is a common form of iron oxide found here on Earth, also often has a reddish color.

So in a way, the ancient connection between the planet Mars and blood wasn’t completely wrong. Rust, which is a common form of iron oxide found here on Earth, also often has a reddish color.

Your blood is also red because of a mixture of iron and oxygen in a molecule called hemoglobin. So in a way, the ancient ...

After its voyage past Mars, Mariner 4 maintained intermittent communication with JPL and returned data about the interplanetary environment for two more years. But by the end of 1967, the spacecraft ...

The spacecraft now almost tips upside down relative to Mars to give its radar the best view. The Mars Reconnaissance Orbiter ...

The new images by the Curiosity rover on Mars show "dramatic evidence" of ancient groundwater in crisscrossing low ridges, ...