Scientists now have the information they need to comprehend the cloud of dust from which the Solar System formed thanks to a piece of old space rock that crashed to Earth.
The unusual item, known as Erg Chech 002, contains an isotope that shows our Solar System may have been infused with radioactive material from recently burst stars near the conclusion of its development.
It provides a fascinating window into the solar environment that existed billions of years ago, demonstrating not only how meteorites may act as time capsules preserving historical secrets but also how those secrets can be used to better comprehend what we find in other space rocks.
Like all stars, the Sun was created from gas and dust. The solar nebula was a massive cloud floating in space, with a portion that was denser and would eventually collapse under the force of gravity to become a young star. As the star spun and developed, it sucked in more and more material. The remaining material disk was used to create the planets once the Sun had consumed its fair share of it.
We have a general understanding of what the nebula included. After all, it is what created our planet as well as all the other planets, rocks, and dust that are currently circling the Sun. But over the roughly 4.6 billion years since the Sun was only a little twinkling in a cloud of dust, a lot has changed chemically in many of those locations.
Contrarily, as meteorites and asteroids have mostly stayed unmodified and unaltered since their formation, it is believed that they provide a relatively clean sample of the Solar System at that time. We may investigate them to learn how they developed, when they did, and what kind of substance they were made of.
This brings us full circle to the unique and ancient meteorite known as Erg Chech 002. The stone, which was found in 2020 in the Erg Chech sand sea in southwest Algeria, has a peculiar andesitic composition connected to igneous activity, which suggests that it was originally a component of a planet that was forming early and whose development was halted.
Magnesium-26, a stable isotope of magnesium, is one of the elements it contains. Magnesium-26 is a decay product of the radioactive aluminum isotope aluminum-26, which is created when big stars have intense supernova explosions.
Despite having a half-life of only 717,000 years, aluminum-26 can be detected in materials and its breakdown products can be utilized to determine the age of the items where they are discovered.
This isotope clock has now been utilized by a group of researchers led by cosmochemist Evgenii Krestianinov of the Australian National University in Australia to deduce the distribution of aluminum-26 in the solar nebula.
Based on the ratios of the meteorite’s radioactive decay products, they determined the meteorite’s age. Their results agreed with earlier estimates of Erg Chech 002’s age, which is 4.566 billion years.
The scientists next made comparisons with other old meteorites with comparable rocky compositions that had been maintained well. Since Erg Chech 002 had substantially more aluminum-26 than the other meteorites, scientists deduced that aluminum-26 was not uniformly distributed across the nebula surrounding our Sun.
These discoveries, according to their interpretation, point to a late infall of star material into the solar nebula that brought with it recently formed radioactive isotopes, such as the aluminum-26 that was absorbed into the developing planet from which Erg Chech 002 originated.
According to earlier study, radioactive elements from supernova explosions were likely thrown into the newborn Solar System at the Sun’s birth. The research done by Krestianinov and his associates adds to our understanding of this puzzling period in ancient history.
The research has been published in Nature Communications.
