Life of one kind or another has been around on this planet for 300 million years longer than thought, according to US researchers who took a close look at some incredibly ancient crystals unearthed in Australia. The scientists say that the zircon crystals from 4.1 billion years ago contain a telltale carbon deposit that appears to have come from something organic, Reuters reports. That's getting closer to the origin of the planet itself, roughly 4.5 billion years ago. Before now, the earliest hint of life was found in rocks 3.8 billion years old. There's no chance the carbon deposit could be any younger than the zircon because the crystal is crack-free and undisturbed, the researchers write in the Proceedings of the National Academy of Sciences.
The zircon crystals were formed during a geological era known as the Hadean, after Hades, because conditions were thought to be so hellish that no life could have existed, the New Scientist notes. The UCLA and Stanford researchers now dispute that, saying life on Earth may have formed "almost instantaneously"—and restarted quickly if it were wiped out at some point. "The early Earth certainly wasn't a hellish, dry, boiling planet; we see absolutely no evidence for that," study co-author Mark Harrison says in a UCLA press release. "The planet was probably much more like it is today than previously thought.” (Earth's first big predator may have been an enormous sea scorpion.)