Scientists have discovered the oldest known piece of Earth—a crystal estimated to be 4.4 billion years old. A relatively new dating technology was used to estimate the age of the zircon crystal found north of Perth. The ratio of oxygen isotopes within the crystal indicates that the Earth of 4.4 billion years ago may have cooled much sooner than had been previously suspected. This might also mean that crust formed and condensed steam may have allowed for ocean waters—and possibly life. If life appeared just 200 million years after the Earth came into existence, this would be a stunning new finding.