A 'fireball' space rock that smashed into a frozen lake in America holds the key to the origins of life on Earth, according to new research from scientists.
The six-foot meteor streaked over the States nearly three years ago, lighting up the sky as it travelled at around 30,000mph before breaking up 20 miles above the ground and cracking into the frozen lake in Michigan.
Using weather radar, scientists were able to locate the meteor pieces, collecting them before the chemical makeup got changed by liquid water.
New analysis published in Meteoritics & Planetary Science says the pristine organic compounds may shed fresh light on how life was kick-started, with the belief that the building blocks of DNA were carried to Earth on meterorites.
Lead author Professor Philipp Heck, a curator at the Field Museum, Chicago, said: "This meteorite is special because it fell onto a frozen lake and was recovered quickly.
"It was very pristine. We could see the minerals weren't much altered and later found that it contained a rich inventory of extraterrestrial organic compounds.
"These kinds of organic compounds were likely delivered to the early Earth by meteorites and might have contributed to the ingredients of life."
Meteorites - which are space rocks that have fallen to Earth after asteroids collide in outer space - appear as 'fireballs' or 'shooting stars' as they travel though Earth's atmosphere.
Heck continued: "Weather radar is meant to detect hail and rain. These pieces of meteorite fell into that size range, and so weather radar helped show the position and velocity of the meteorite. That meant that we were able to find it very quickly."
Less than two days after the meteor landed on 16 January 2019, the first piece was found by meteorite hunter Robert Ward on the frozen surface of Strawberry Lake near Hamburg, Michigan.
It was donated to the Field Museum, where Heck and a graduate student called Jennika Greer could study it.
Greer said: "When the meteorite arrived at the Field, I spent the entire weekend analysing it, because I was so excited to find out what kind of meteorite it was and what was in it.
"With every meteorite that falls, there is a chance there is something completely new and totally unexpected."
The team were quickly able to determine that it was a rare type of meteorite known as an H4 chondrite, but it is particularly exceptional as it was collected so quickly and has been so well analysed.
Greer continued: "This meteorite shows a high diversity of organics, in that if somebody was interested in studying organics, this is not normally the type of meteorite that they would ask to look at.
"But because there was so much excitement surrounding it, everybody wanted to apply their own technique to it, so we have an unusually comprehensive set of data for a single meteorite."
While scientists don't know for sure how the carbon-containing organic compounds responsible for life got here, one popular theory is that they came to Earth on meteorites - as it's possible some of these organic compounds first formed in an asteroid that later fell here.
Heck said: "Scientists who study meteorites and space sometimes get asked, do you ever see signs of life?
"And I always answer, yes, every meteorite is full of life, but terrestrial, Earth life. As soon as the thing lands, it gets covered with microbes and life from 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."
Using a wide variety of analytical techniques and samples from different parts of the meteor, the researchers have been attempting to get more of a complete picture of the minterals it contains.
Greer said: "You learn a lot more about a meteorite when you sample different pieces. It's like if you had a supreme pizza, if you only looked at one little section, you might think it was just pepperoni, but there might be mushrooms or peppers somewhere else."
Heck added: "This study is a demonstration of how we can work with specialists around the world to get most out of the small piece of raw, precious piece of rock.
"When a new meteorite falls onto a frozen lake, maybe even sometime this winter, we'll be ready. And that next fall might be something we have never seen before."
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