Previously, it had been thought that 'frequent large impacts' (illustrated) on Earth ended about 3.8 billion years ago. However, recent discoveries have suggested that large impacts from asteroids between 12 and 62 miles (20 and 100km) across continued until 3.2 billion years agoMike Agliolo/Corbis
According to the prevailing theory, the Earth was formed 4.5 billion years ago. Experts estimate that a billion years later, our planet had begun to take shape geologically and atmospherically and, gradually, it transformed to the biosphere, as it is today.
During that period, the Earth was bombarded by giant asteroids with diameter 20-100 km that caused smaller and larger-scale disasters and changes on the planet. As stated by the new study, the giant asteroids that fell on Earth 3.3 billion years ago, led to cataclysmic results.
According to researchers, these impacts increased the temperature of the Earth's atmosphere so dramatically that the surface of the oceans boiled and evaporated huge quantities of seawater into the atmosphere. Experts estimate that the temperature on the planet rocketed to 500 degrees Celsius. This temperature was maintained for a few weeks and then stabilized for a period of twelve months at 100 degrees Celsius.
The researchers mention that “Oceans at that time had become a giant hot spring". What is more, they estimate that the impact of asteroids on Earth affected the growth and stability of the Earth's crust, which had just started to be created.