1 billion years' worth of big asteroids hit moon recreated in a 1-minute animation
Washington, Jan 24: Earth and Moon have faced asteroid collision threats more in the last 290 million years. The number of asteroids colliding with the Moon and the Earth was about two to three times higher in the last 290 million years than in the previous 700 million years.
According to an IANS report, the aforementioned study challenges the previously understood history of the Earth's history.
For decades, scientists have tried to understand the rate that asteroids hit the Earth by carefully studying impact craters on continents and by using radiometric dating of the rocks around them to determine the ages of the largest, and thus most intact, ones. The problem is that many experts assumed that early Earth craters have been worn away by wind, storms, and other geologic processes. This idea explained why Earth has fewer older craters than expected compared to other bodies in the solar system, but it made it difficult to find an accurate impact rate and to determine whether it had changed over time.
So a new study published this week in the journal Science took a close look at the biggest lunar craters. By counting and dating such impact sites, the researchers suggest, an approximate history of asteroid strikes on Earth can be reconstructed.
The team of researchers analyzed images taken by NASA's Lunar Reconnaissance Orbiter (LRO) to gauge how old these craters are. The study showed a total of 111 major impact sites over a period of 1 billion years.
The team also put together 1.3 billion years' worth of impact data from the moon's surface with help from animators in a minute-long musical treat. The animation illustrates 111 of the moon's larger impact craters as sound and colour - in the same order that they took place in.