Asteroid Ryugu, a carbon-rich rock in close proximity to Earth, has yielded intriguing clues about its complex journey through the solar system. Recent analysis of grains collected from Ryugu suggests that this asteroid originated in the outer regions of the solar system, then migrated into the asteroid belt and eventually ended up near Earth. These results shed light on the tangled history of asteroids and emphasize their role as a valuable source of information about the solar system’s past.
Ryugu, classified as a Type C asteroid, is a common type of space rock containing large amounts of carbon and water. Ryugu is normally located in the Main Belt between Mars and Jupiter, but its orbit around the Sun deviates significantly from this region, indicating that it experienced a destructive event that moved it out of its original position.
Launched in 2014 by the Japan Aerospace Exploration Agency (JAXA), the sample return probe Hayabusa2 conducted extensive studies of Ryugu from 2018-2019 before returning to Earth in 2020. In addition to collecting samples, Hayabusa2 found that Ryugu is not a single solid mass, but rather a “debris pile” made up of smaller rocks held together by gravity.
Although Ryugu shares features with Main Belt asteroids such as Polana and Eulalia, recent studies of samples recovered from Ryugu have shown that some minerals within the debris have characteristics more closely resembling materials found in the outer solar system. In particular, the organic matter and oxygen isotopes found on Ryugu resemble those typically associated with comets originating from the outer regions of the solar system.
To further explore the findings, astrophysicist Rosario Brunetto and her collaborators at the University of Paris-Sarclay analyzed grains rich in olivine, pyroxene and amorphous silicates. These grains, the least affected by the asteroid’s water content, were examined using infrared spectrometry. The research team found that the infrared light reflected by these grains is very similar to objects from the outer solar system, including the Trojan asteroid Hektor, comet Hale-Bopp, and interplanetary dust likely of cometary origin.
Based on their findings, the researchers hypothesize that Ryugu’s primary parent body was a planetesimal, a potential precursor planet that originally formed in the outer solar system, absorbing materials from that region. However, an unknown disturbance prevented its growth, possibly causing it to fragment and move to the Main Belt, where it underwent a water-altered transformation.
The significance of the Ryugu asteroid lies in the fact that it provides valuable evidence of the evolution of the solar system. By studying its composition and origin, scientists can gain crucial insights into the history and dynamics of our celestial neighborhood.
“Analysis of grains from the asteroid Ryugu provides compelling evidence for its extraterrestrial origin and journey through the solar system. The complex history of this asteroid reveals the complex migrations and transformations that asteroids can undergo before ending up in their current locations.” – Rosario Brunetto, astrophysicist at the University of Paris-Sarclay.
Scientific and historical information:
– Asteroid Ryugu is a C-type asteroid, rich in carbon and water, typically found in the Main Belt between Mars and Jupiter.
– Ryugu’s orbit deviates from the Main Belt, suggesting that it experienced a destructive event that displaced it from its original location.
– The Hayabusa2 probe, launched by JAXA in 2014, conducted extensive studies of Ryugu in 2018-2019 and returned to Earth in 2020.
– Ryugu is made up of small rocks bound together by gravity, which is called a “debris pile.”
– Recent studies of samples recovered from Ryugu have shown that some minerals resemble those found in the outer solar system, including organic matter and oxygen isotopes associated with comets.
– Infrared spectrometric analysis of grains rich in olivine, pyroxene and amorphous silicates revealed similarities between Ryugu and objects in the outer solar system, such as the Trojan asteroid Hector, Comet Hale-Bopp and interplanetary dust likely of cometary origin.
– The researchers hypothesize that Ryugu’s primary parent body was a target planet that originally formed in the outer solar system but was destroyed and moved to the Main Belt, where it underwent a water-altering transformation.
“The results of analyzing grains collected from the asteroid Ryugu provide valuable insight into the complex history of asteroids and their importance as witnesses to the evolution of the solar system. This study expands our understanding of the
