2.4 billion years ago, the earth is a "snowball" [abstract], according to scientists study the earth 2.4 billion years ago is a complete "snowball", equatorial regions keep temperature of minus 40 degrees Celsius, at the same time, suggests that such as Europa's frozen planet might have supported living things.
A new study suggests that the earth 2.4 billion years ago in a deep freeze, the equator only minus 40 degrees Celsius temperature, suggests potential planets such as Jupiter's moon EuropalifeThere are signs.
Current temperatures will reach 30 degrees Celsius in the tropics, but in the 2.4 billion years ago, the equator zone temperature is similar to the North Pole, keep the minus 40 degrees Celsius, the earth is a complete "snowball".
This period was known as the "snowball earth", the earth may be completely frozen, Europa and enceladus second-class frozen planet at the same time looking for life to provide important clues.The study by Daniel about the university of cologne in Germany watts (Daniel Herwartz), responsible for the Dr Details study published recently in the journal proceedings of the national academy of sciences.
Research suggests that the earth 2.4 billion years ago in the "deep freeze", sea ice thickness up to 300 meters, means that if the earth there is life, is likely to survive under the ice.Europa and so on other planets in our solar system also exist ice shell surface, scientists think that a liquid ocean under the ice shell.
Hector watts said: "these phenomena is very attractive, and our earth is a completely frozen 2.4 billion years ago the world."At the same time, the research theory helps to explain "sufficient oxygen transition period",
2.2 billion years ago when atmospheric oxygen levels increased from 0.0001% to 21% today.The entire earth rapid melting caused the atmospheric oxygen levels increased.
Hector watts pointed out that before 2.4 billion, the earth's climate is "normal", similar to today's climate.At the same time, he says, atmospheric carbon dioxide index decline is likely to cause the earth become a "snowball", when co2 index fell, the ice sheet will grow bigger, because the ice is white, a large number of incoming light is reflected back into space, then more ice will reflect more the incident sunlight, the earth gradually gets cold.Climate models predict results show that when the temperature reaches a certain critical point, the earth will be completely frozen.After a lot of sunlight is reflected back into space, the earth into a complete "snowball".