Cosmic dust may have been crucial to the beginnings of life on Earth

Space dust may have brought elements essential for life to early Earth. Our planet is relatively poor in some of the elements necessary for the chemical reactions of life, but the dust that constantly drifts in from space contains many more, and when the Earth was young it was covered with glaciers. It is possible that they were gathered in

“This has always been a shadow idea, and people have ignored it for a number of reasons. The biggest one is that there just weren’t enough ideas anywhere,” he said. say. craig walton at Cambridge University. Space dust tends to be rich in elements that are relatively difficult to obtain on Earth, such as phosphorus and sulfur, and it constantly falls in thin layers around the world.

Until now, researchers exploring the origins of such elements on Earth have focused primarily on larger objects that can deliver more elements at once, but such delivery mechanisms were They may have a hard time maintaining their pre-biological chemistry long enough to do so, Walton says. “Meteorites have long been thought to be a great source of these elements, but they release them randomly,” he says. “It’s like if I give you a big feast once, but you never eat again, you’re going to have a hard time living a happy life. You need a continuous source, and that’s what happens. It’s space dust.”

Up to 40,000 tons of space dust falls on Earth every year. Billions of years ago, that number may have been between 10 and 10,000 times higher, but that was still not enough to make individual locations particularly rich in elements important to life. Walton and his colleagues simulated how dust is moved by wind and water and collected in concentrations high enough to support life.

They found that glaciers are the most promising environment because they have the potential to trap large amounts of dust and are very less contaminated by dirt on land. When space dust falls on a glacier, it absorbs sunlight and heats up, melting and creating tiny holes in the ice. The hole then continues to trap more dust. Finally, the dust chamber flows into a pond at the edge of the glacier.

We can still see this process happening today, but if the Earth had been cold enough to have glaciers billions of years ago, the amount of dust would have increased and it would have been even more efficient. . “If you want to produce deposits that are really rich and have a lot of reactions that could lead to life, this is the best way to do it,” Walton says.

“We don’t know if glaciers were common on early Earth; we just don’t have good data for this period in general,” he says. ben pierce at Johns Hopkins University in Maryland. “But I think it’s worth investigating, especially if it has the potential to provide a mechanism for creating a rich primordial soup.”

The lack of data about conditions on Earth during this time makes it difficult to estimate how important cosmic dust was to the origin of life. “We’ve always had a hard time understanding what the bulk chemistry of early Earth was like,” he says. Matthew Pasek at the University of South Florida. “However, this could be an important source of extremely valuable material.”