A fireball that fell to Earth in 2018 contains “pristine extraterrestrial organic compounds” that could help tell us how life was formed, scientists say.
The meteor arrived on Earth in January 2018, as a streaked fireball visible in the midwestern United States sky. Scientists were able to track it down using weather radar, and hunters collected the meteorite from the ground before its chemical composition was changed by exposure to liquid water.
Now the researchers say the material they recovered gives them the ability to explore rocks that might appear while still in space, but using the equipment they have on Earth.
They describe their first findings in a new article published in the journal Meteorites and planetary sciences.
“This meteorite is special because it fell on a frozen lake and was recovered quickly. It was very pristine. We could see that the minerals weren’t much altered and we later found that it contained a rich inventory of extraterrestrial organic compounds,” says Philipp Heck, curator of the Field Museum, associate professor at the University of Chicago and lead author of the new article.
“These types of organic compounds were likely delivered to early Earth by meteorites and may have contributed to the ingredients of life.”
When the fireball arrived, the researchers were able to track the pieces using NASA technology usually reserved for time tracking.
“The weather radar is meant to detect hail and rain,” Heck said. “These meteorite pieces fell in that size range, and so the weather radar helped show the meteorite’s position and speed. That meant we were able to find it very quickly.”
The first pieces were recovered by meteorite hunter Robert Ward, who found them on the frozen surface of Strawberry Lake in Michigan. He gave his discovery to the Field Museum, which began the research that culminated in the newly published paper.
That research showed that the meteorite was an H4 chondrite, which represents only 4% of the objects falling to Earth. But it was even more remarkable because it was detected so quickly that it remains relatively untouched by conditions on Earth.
This could help researchers in their quest to understand how the organic compounds that helped form life got to Earth. One possibility is that they were brought to the planet by similar meteorites, so studying such examples could help us understand if such a story is likely.
“Scientists who study meteorites and space are sometimes asked, do you ever see signs of life? And I always answer, yes, every meteorite is full of life, but terrestrial, the life of Earth,” says Heck.
“As soon as the thing lands, it becomes covered in microbes and life from the Earth. We have meteorites with lichens growing on them. So the fact that this meteorite was collected so quickly after it fell, and that it landed on ice rather than in the dirt helped keep it cleaner “.