The best candidates for binary craters on Earth today are the Swedish Rock’n Crater and the nearby small crater called Moringen. “We have dated these structures very accurately and confirmed that they were formed at exactly the same age,” said the crater, published in 2014, about 450 million years ago. Jens Olme of the Center for Astrobiology in Spain, who led the analysis, says. The Kamenskrate and Gusev craters are known, but their location on the Russian-Ukrainian border makes them difficult to study in the current global climate.
On Mars, craters can remain visible for billions of years. So, using high-resolution images of the surface taken by the Orbiter of Mars, Vavilov and his colleagues examined about 32,000 craters over 4 km in diameter to find a pair of craters.
Their results showed that 150 pairs were the result of binary influences, for a total of 300 individual craters. These estimates are obtained by looking for pairs of crater shapes expected after a binary asteroid collision. These include teardrop craters where two craters overlap. Peanut craters, they are connected at their ends. A doublet crater with a gap between the two. The orientation of the two craters depends on the position of the two asteroids at the time of the collision.
“I didn’t know how many were on Mars,” says Catalina Milikovich of Curtin University, Australia. He did initial modeling in 2013 to show the expected crater shape, but was not involved in this latest work. “Someone had to do a lot of research to find them all. I think it’s great.”
Since two asteroids collide with the surface at the same time, it can lead to some interesting physics. Elliot Sefton-Nash, a deputy project scientist at ESA’s Delayed ExoMars program, states that shock waves from impacts can collide and create a raised ridge between two craters or some high-pressure location. .. “It’s like going the other way on the highway,” he says. “You may be able to see the difference in minerals that are formed only under very high pressure.”
In total, the number of binary asteroids found on Mars is only about 0.5% of all craters over 4 km on Earth. This is well below most estimates of the number of binary asteroids in our solar system. This may be the result of some of the effects being wiped out by natural weathering. Alternatively, there may be small crater pairs less than 4 km in diameter. “There are more than 100 million impact craters over 100 meters,” says Anthony Lagain of Curtin University, Australia, who co-authored the study. “Once you start building small craters, you have to spend a lot of time reviewing them all.”
Many of the crater pairs are similar in size, which contradicts the main theory of how binary asteroids are created. It is believed that such a system is formed as a result of the light from the Sun hitting an asteroid, pushing matter from the surface of the asteroid into orbit. As the asteroid spins, this material becomes a small companion over millions of years. This is evidenced by the composition of most binaries observed so far.