A rare meteorite that exploded as a fireball over California’s Sierra foothills earlier this year has left scientists pondering the possibility of a similarly-sized object hitting Earth.
An international team of scientists, who announced their findings in a series of published papers in Friday’s edition of the journal Science, say the meteorite struck with the force of several atomic bombs. The high-speed, minivan-sized meteorite was likely much larger when it hit Earth’s atmosphere. Astronomers estimate that the meteorite weighed an estimated 100,000 pounds when it entered the atmosphere at about 64,000 miles per hour. The estimated speed makes it one of the fastest, “most energetic” reported meteorite since 2008, when an asteroid fell over Sudan.
While the meteorites discovery has left the astronomy community rejoicing, study co-author and University of California-Davis geology professor Qing-zhu Yin warned that the piece of cosmic rock could have struck Earth with disastrous results.
“If this were a much bigger object, it could have been a disaster,” said Yin. “This is a happy story in this case. “
The scientists learned that the meteorite formed about 4.5 billion years ago. It was knocked off its parent body, which may have been an asteroid or a Jupiter-family comet, roughly 50,000 years ago. The researchers say the meteorite is a major discovery for the astronomy community, noting its rare composition. According to the published report, the space rock is among the rarest type known to have hit the Earth — a carbonaceous chondrite.
Among the factors that may have saved a small California town from destruction is the fact the meteorite arrived at a record entry speed of nearly 18 miles per second, breaking apart at a record altitude of about 34 miles above sea level.
“The entry was very violent,” said Peter Jenniskens, a senior researcher at the Search for Extraterrestrial Intelligence Institute and the study’s lead author. “We think that’s why there were no big chunks, because this object came in with such a high speed.”
While the discovery is likely to present astronomers with an overwhelming amount of data concerning the early days of the universe, researchers expressed optimism concerning their ability to recover even more meteorites in the future.
For the first time, the Doppler weather radar network helped track the falling carbonaceous chondrite meteorite pieces, aiding scientists in the quick recovery of them, the study reports. Yin expects that the weather radar data in the public domain could greatly enhance and benefit future meteorite recoveries on land.
“For me, the fun of this scientific gold rush is really just beginning,” said Yin. “This first report based on the initial findings provides a platform to propel us into more detailed research. Scientists are still finding new and exciting things in Murchison, a similar type of meteorite to Sutter’s Mill, which fell in Victoria, Australia, in 1969, the same year Apollo astronauts Neil Armstrong and Buzz Aldrin returned the first lunar samples to the Earth. We will learn a lot more with Sutter’s Mill.”
While Meteorites similar to Sutter’s Mill have wrought destruction in the past, they are also thought to have delivered oceans of water to Earth early in its history.