An ancient piece of space rock that has landed on Earth is giving scientists the clues they need to understand the dust cloud that gave birth to the solar system.
One of the isotopes found in the rare object Erg check 002A indicates the presence of radioactive material scattered by recently exploded stars that filled our solar system at the end of its formation.
A fascinating look at the solar environment that existed billions of years ago not only shows how meteorites can act as time capsules that hold the secrets of the past, but that these secrets can also be used to better understand what we find in other space rocks.
The sun, like all stars, was born from gas and dust. The solar nebula was a dense cloud floating in space, the denser part of which collapsed under the influence of gravity, forming a young star, which, as it rotated and grew, merged into more and more material. After the Sun absorbed its saturation, the remaining disc of material entered into planetary formation.
We have a rough idea of what was in the nebula. After all, our planet and all the other planets, stones and dust drifting through the solar system were formed from it. But a lot has changed chemically in these places in about 4.6 billion years since the sun was just a glimmer in a cloud of dust.
In contrast, meteorites and asteroids are thought to represent a relatively primitive sample of the solar system when these bodies formed, as they have remained largely unchanged or changed since then. Thus, we can study them to find out when they were formed and what composition they consist of.
This brings us back to Erg Cech 002, a Pearless meteorite that is older than Earth. Discovered in 2020. Check if I want. In the Sand Sea in southwestern Algeria, the rock has an unusual andesitic composition associated with volcanic activity, suggesting that the object was once part of an early-forming planet whose development was halted early.
One of its elements is the stable magnesium isotope magnesium-26. Magnesium-26 is the decay product of a special radioactive isotope of aluminum, aluminum-26, which is formed during the violent death of supernovae of massive stars.
Aluminum-26 has a relatively short half-life of 717,000 years, but its decay products can be used to infer its previous existence in materials and calculate the age of objects in which it is found.
Now a team of scientists led by Australian National University cosmologist Yevgeny Kristianinov has used this isotope clock to infer the distribution of aluminum-26 in the solar nebula.
They calculated the age of the meteorite based on the ratio of its radioactive decay products. Their calculations were in line with previous estimates of the age of Erg Cech 002 at 4.566 billion years.
The team then compared it to other ancient, well-preserved meteorites with a similar rock composition. They found that Erg Cech 002 contains significantly more aluminum-26 than other meteorites, meaning that aluminum-26 is unevenly distributed in the solar nebula.
The results are believed to reflect a late fall of stellar material into the solar nebula, bringing with it newly formed radioactive isotopes, including aluminum-26, that were delivered to the nascent planet from which Erg Cech 002 originated.
Previous research suggests that the nascent solar system was flooded with radioactive material from supernova explosions during the birth of the sun. The work of Kristianinov and his colleagues is another piece of the puzzle in this strange period of our ancient history.
The study was published in natural communications.