Geologists have long studied the few traces of this period preserved in rock in the hopes of learning more about Earth’s conditions. The only surviving records from between 4.6 and 4 billion years ago are found in zircon, a hardy crystalline mineral. It is critical, however, that scientists learn as much as they can about this period, because it was in these inhospitable and hellish conditions that life began.
According to Hadean Bioscience colleagues, the first Earth was a ‘naked planet,’ with no ocean or atmosphere when it formed. These first appeared around 4.37 billion years ago, after being bombarded by aqueous asteroid material. Once there was liquid water and an atmosphere, prebiotic life had a better chance of forming (the chemical precursors to life on Earth). The earliest signs of life on Earth are thought to date back as far as 4.2 billion years, implying that life could have evolved within 200 million years of the appearance of liquid water.
