'Pristine' meteorite may provide clues to the origins of our solar system

It was found on a frozen lake after lighting up Michigan skies in 2018.

Meteorics & Planetary Science

A meteorite that lit up the night sky in the US Midwest in 2018 contains ‘pristine’ organic compounds that may offer clues to how life formed on Earth, according to researchers (via the Independent). It was spotted by motorists and others in several states after producing a fireball and loud explosion on January 18, 2018. Thanks to some quick thinking and action, the rocks were quickly in the hands of researchers before they could be contaminated.

Less than two days after it streaked across the sky, meteorite hunter Robert Ward found the first piece resting on the frozen surface of Strawberry Lake near Hamburg, Michigan. He was able to pinpoint the location by using NASA’s weather radar, as the meteorite chunks were similar in size to hail. He quickly got it to the Field Museum in Chicago, where curator Philipp Heck quickly set about studying it.

“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,” Heck said in a statement. “These kinds of organic compounds were likely delivered to the early Earth by meteorites and might have contributed to the ingredients of life.”

The researchers determined that it was a rare H4 chondrite meteorite, representing only four percent of those found on Earth. The initial analysis determined that it contained over 2,600 separate organic compounds that were still intact despite the intense heat created when it blazed through the atmosphere. They also found that it likely broke off 12 million years ago from its parent asteroid, which formed 4.5 billion years earlier.

A lot of scientists were able to probe the rock using different techniques, “so we have an unusually comprehensive set of data for a single meteorite,” said Heck.

While the meteorite was as clean as one that lands on Earth can be, scientists are especially anxious to get their hands on a truly pristine specimen from the source — space. That’s scheduled to happen in 2023. when the NASA spacecraft Osiris-REx is set to return to Earth after it successfully grabbed and stowed a chunk of regolith from the asteroid Bennu.