4.4 bn year old zircon reveals life on Earth appeared earlier than believed
24 February, 2014
Ancient zircon crystals, discovered in Australia in 2001, have now been proved to be our planet’s oldest known substance. The 4.4 billion-year-old gem offers clues that Earth could have become habitable much earlier than previously believed.Our planet formed as a ball of molten rock 4.54 billion years old. The first 500 million years of Earth have been dubbed Hadean, after the ancient Greek god of the underworld, or hell-like, because scientists believed that it was covered with lava and subsurface magma, making it an absolutely inhospitable place.