The possibility that Mars was once a habitat to all sorts of life seems bigger with each new Curiosity discovery. Newly published research reports that the rover has stumbled upon a site in the Gale Crater that scientists believe might have once been a lake full of life.

This lake site would have been full of water some 3.6 billion years ago, and it's also full of all the chemical signatures for life—like carbon, hydrogen, oxygen, nitrogen, and sulfur. The findings are detailed in six papers in the latest edition of Science, one of which suggests that the life could have been chemolithoautotrophs, or resilient little critters that live in thermal vents deep beneath the ocean's surface.

Evidence of life of Mars isn't anything new. Earlier this year Curiosity found evidence of clay minerals that could only have been formed in water that wasn't too acidic or basic - technically, water that could have supported life. The old lake site in the Gale Crater bears similar telltale signs, as well as the right life-friendly chemical signature. Professor John Grotzinger, project scientist on the Curiosity mission, says, "The whole thing just seems extremely Earthlike."

What we need now are organics; the building blocks of life. There's a chance that these molecules were zapped by radiation long ago. But scientists are still hopeful, and the Curiosity will keep looking.