Meteorite that landed in Botswana tracked to its birthplace in the asteroid belt

Some notes here from the report I find very interesting. "2018 LA originally measured about 5 feet (1.5 meters) in diameter and had been zooming around in space for about 22 to 23 million years before crash-landing on Earth, the team determined. The rock was traveling about 37,280 mph (60,000 km/h) before entering the planet's atmosphere, according to the ANU statement. "

My observation. This is the CRE age obtained on the meteorite. Given 4 Vesta orbital period of about 3.63 years, this object could orbit the Sun for some 6.336 million revolutions before hitting Earth based upon the CRE age. We have the radiometric age provided too, "The oldest known materials found in both Vesta and in the meteorite are zircon grains that date back to more than 4.5 billion years ago, during the early phase of the solar system," Onken noted."

My observation. 4 Vesta in 1 billion years could complete 275 million revolutions around the Sun, so many more in 4.5 billion years. We also have a date for an impact event on 4 Vesta too in explaining the origin of the meteorite.

"Despite both being HED meteorites, though, Motopi Pan and Sariçiçek differed in several ways. For instance, the team estimated that the material in both meteorites likely solidified on Vesta's surface about 4.563 billion years ago, but phosphate grains in Motopi Pan showed evidence of having melted in more recent history, while Sariçiçek did not bear these markings. This hinted that Motopi Pan formed close to the center of a large impact event that took place about 4.324 billion years ago, the team concluded. They suspect that the same event formed a giant dent, known as the Veneneia impact basin, on Vesta's surface. "We now suspect that Motopi Pan was heated by the Veneneia impact, while the subsequent Rheasilvia impact," which occurred later and partially obscures the Veneneia impact basin, "scattered this material around," Jenniskens said. "Because the team tracked the rock from space all the way down to the impact site, they were able to calculate a very precise orbit that is consistent with an origin near Vesta, providing one of the best links we have between an asteroid and meteorites," Ashley King, a planetary scientist at the Natural History Museum who was not involved in the work, told The Guardian. The team described their findings in a new study published in the journal Meteoritics and Planetary Science."

My observation. So we have a CRE age 22 to 23 million years old, another age 4.563 billion years old for when the meteorite solidified on 4 Vesta surface, and an impact event 4.324 billion years ago. Based upon the meteorite CRE age, the object may orbit some 6.336 million revolutions around the Sun before hitting Earth. The meteorite as part of 4 Vesta, could complete at least 275 million revolutions around the Sun in 1 billion years, many more given the other dates provided too, before hitting Earth and analyzed today.

I was glad to read this meteorite report because details like this are not commonly reported (in my opinion). It shows how dating the age of the solar system works as well as methods used to reconcile different ages obtained when found on these objects today (meteorites).
FYI. I did a bit more digging into this report. Here are some additional notes.

The impact and recovery of asteroid 2018 LA,, this is a very detailed study paper on the meteorite showing various isotope ages and CRE age obtained.

On the Pre-impact Orbital Evolution of 2018 LA, Parent Body of the Bright Fireball Observed Over Botswana on 2018 June 2,

Vesta fragments from v6 and 3:1 resonances: Implications for V-type NEAs and HED meteorites,

My observation. These earlier studies are important to the discussion posted 28-April-2021 on the meteorite 2018 LA. The v6 resonance is out near 2.1 au according to the paper attached (14 pages). reported on this meteorite find along with other sources on 28-April-2021. The research paper (very detailed) shows the v6 resonance is used to explain the origin of this meteorite along with some other characteristics as coming from 4 Vesta asteroid and then hitting Earth only recently. The CRE age of about 23 million years compared to the radiometric ages reported is very intriguing. Meteoroids in the v6 resonance and 2018 LA orbiting near 1.4 au (thus an NEO before hitting Earth), are all short lived bodies in the heliocentric solar system (commonly reported <= 10 million years) and do not have stable orbits over billions or many millions of years. So different ages obtained via radiometric methods and CRE ages must be reconciled with the 4.56 billion years old solar system age. The Vesta fragment paper's Conclusions section shows how difficult it is to reconcile various CRE ages with the very young dynamical time found for the v6 resonance and 3:1 resonance, typically 2 million years or less for these small bodies in the asteroid belt region to remain stable.

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