Large space rocks that hit Earth, like the one that killed off the dinosaurs that couldn’t fly, are like asteroids that impact the moon millions of years ago. The discovery shows that significant impacts during Earth’s prehistory were not singular occurrences. The moon, whose surface is covered in over 9,000 craters from space rock impacts, was instead hit by a series of smaller hits in addition to this asteroid impact.
The study could help astronomers better understand how the inner solar system works and figure out how likely it is that large, potentially dangerous space rocks will hit Earth in the future.
Researchers from Australia’s Curtin University‘s Space Science and Technology Centre (SSTC) found these results by looking at tiny glass beads found in soil samples from the moon that China’s Chang’e-5 lunar mission will bring back to Earth in 2020.
The intense heat and pressure produced by meteor strikes led to the formation of these tiny glass beads. This means that scientists can make a timeline of the bombardment of the moon by figuring out how old these beads are.
While doing this, the SSTC team discovered that the timing and frequency of space rock impacts on Earth were identical to those on the moon, suggesting that the timeline they created may also shed light on the history of our planet.
In a statement, Alexander Nemchin, a professor at SSTC and the study’s lead author, said in a statement, “We combined a wide range of microscopic analytical techniques, numerical modeling, and geological surveys to determine how and when these microscopic glass beads from the moon were formed.”
The ages of some of the lunar glass beads revealed that they were made around 66 million years ago, at the same time that the dinosaur-killing Chicxulub impactor asteroid struck Earth near Mexico’s Yucatán Peninsula in what is now the Gulf of Mexico.
The impact caused the Cretaceous–Paleogene extinction event, which ultimately resulted in the extinction of the nonavian dinosaurs and three-quarters of all life on Earth.
The Chicxulub impactor, which was about 6.2 miles (10 kilometers) wide, hit Earth at a speed of about 43,200 mph (69,524 kph), leaving an asteroid impact crater that is about 93 miles (150 km) wide and 12 miles (19 km) deep. After the asteroid hit, it set off a chain of events that changed people’s lives, such as the formation of thick dust clouds that blocked the sun.
The latest findings from SSTC support earlier research that suggests that, in addition to the massive asteroid that killed the dinosaurs, there may have been other, smaller asteroids that also hit Earth. If you look at the history of asteroid impact on the moon, you might be able to figure out where these other asteroids are.
The research revealed that numerous smaller impacts may have preceded major impact craters like the Chicxulub crater, which formed 66 million years ago. If this is true, it means that the age-frequency distributions of impacts on the moon could be a good way to learn about impacts on Earth or other planets in the inner solar system.
The team’s current goal is to compare the information gathered from the Chang’e-5 lunar soil samples to that of other moon soil samples as well as to the ages of craters found on the lunar surface. This analysis could find evidence of more asteroid impacts on the moon, which could lead to evidence of asteroid impacts on Earth that may have changed life.
