The Hadean geologic eon began when the Earth was formed an estimated 4.6 billion years ago and ended approximately 800 million years later. There remain few geological traces of this period on Earth, but toward the end of the 20th c, geologists identified a few rocks and zircon crystals that dated to the Hadean. The eon’s name is derived from Hades, a Greek word now used as a synonym for hell, and may be a reference to the conditions on Earth at the time. How hot was Earth’s surface then? Discuss
Source: The Free Dictionary