Scientists Crack 4.6-billion-year-old Space Mystery Using Asteroid Dust – The Daily Galaxy –Great Discoveries Channel

Scientists analyzing asteroid Ryugu’s ancient grains have uncovered a long-lost magnetic force that may have shaped the outer solar system. Could this discovery rewrite what we know about planet formation?Tiny grains collected from the asteroid Ryugu have given scientists a new window into the magnetic forces that shaped the outer solar system over 4.6 billion years ago. By analyzing these ancient particles, researchers have uncovered evidence that a weak but persistent magnetic field may have played a critical role in the formation of gas giants like Jupiter and Neptune, influencing how planetary material coalesced in the early solar system.According to a recent study published in AGU Advances, a team of scientists from MIT, Caltech, and Harvard examined the magnetic properties of Ryugu’s dust grains, which were returned to Earth by Japan’s Hayabusa2 mission.The asteroid Ryugu is believed to have originated in the distant reaches of the early solar system before being drawn into the asteroid belt between Earth and Mars. In 2020, Japan’s Hayabusa2 mission successfully returned samples of Ryugu’s surface to Earth.Scientists had been eager to examine these pristine space grains, hoping they would hold clues about conditions in the early solar system.The team analyzed the samples for traces of ancient magnetic fields, searching for signs that a nebular field existed beyond 7 astronomical units (AU)—the region where gas giants formed.Previous studies had confirmed that the early inner solar system was shaped by a strong magnetic field, which helped direct gas and dust toward forming planets like Earth, Venus, and Mars. However, whether this force extended to the outer planets remained a mystery.Using a magnetometer, the researchers “rewound” the magnetic history stored within Ryugu’s grains. Their findings revealed that if a nebular magnetic field existed in the outer solar system, it was extremely weak—no more than 15 microtesla (compared to Earth’s current 50 microtesla).“This nebular field disappeared around 3 to 4 million years after the solar system’s formation, and we are fascinated with how it played a role in early planetary formation,” explained Elias Mansbach, the study’s lead author.Despite its faint strength, this force would have been sufficient to attract gas and dust, contributing to the growth of massive planetary bodies like Jupiter and Saturn.The research team compared their results to other meteorites believed to have formed in the outer solar system. One sample, known as an ungrouped carbonaceous chondrite, exhibited a weak magnetic field of around 5 microtesla, consistent with Ryugu’s data.This suggests that even the most distant regions of the solar nebula may have been influenced by magnetic forces, contradicting older models that assumed these outer zones lacked significant magnetic activity.“We’re showing that, everywhere we look now, there was some sort of magnetic field that was responsible for bringing mass to where the sun and planets were forming,” said Benjamin Weiss, an MIT planetary scientist and co-author of the study.Comment Save my name, email, and website in this browser for the next time I comment.

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