Why is Mars barren and uninhabitable, while life has always thrived here on our relatively similar planet Earth?

See Rocket Lab's "proposed mission architecture" for a Mars sample return mission in this animation. Credit: Rocket Lab ...

NASA's Phoenix lander, which touched down on Mars in 2008, initially struggled to scoop the planet’s rusty red regolith into a device that heats the rocks to sniff out their components.

In an unexpected turn of events, NASA’s Curiosity rover has cracked open a rock on Mars, uncovering something so surprising ...