Samples from Ryugu prove the truly delicate and long-lived nature of the rubble-pile asteroid
Two new studies of samples brought back from the rubble-pile asteroid Ryugu by the Japanese probe Hayabusa-2 have found that the asteroid not only was never heated above 86 degrees Fahrenheit, it also contained dust grains older than the solar system itself.
The evidence from the first study, completed by Japanese scientists, suggested that:
- 1.Asteroid Ryugu accreted some components that originated in the outer Solar System and contained abundant water and organics. The asteroid then traveled to the inner Solar System.
- 2.Organics associated with coarse-grained phyllosilicates may serve as one of the potential sources of water and organics to the Earth.
The second study, using samples provided to American scientists, found two tiny dust grains that must have come from the material that existed before the formation of our solar system.
The team detected all the previously known types of presolar grains—including one surprise, a silicate that is easily destroyed by chemical processing that is expected to have occurred on the asteroid’s parent body. It was found in a less-chemically-altered fragment that likely shielded it from such activity.
This is not the first discovery of presolar grains, but their delicate existence in Ryugu confirms the conclusions of the first study, that Ryugu had to have formed in the outer solar system and then migrated inward over eons.
The second study also reviewed the make-up of the sample and concluded that Ryugu appears to most closely match the family of carbonaceous Ivuna-type (CI) chondrites, thought to be among the most primitive asteroids known, of which very few have been studied because of they rarely survive the journey through the Earth’s atmosphere.
Two new studies of samples brought back from the rubble-pile asteroid Ryugu by the Japanese probe Hayabusa-2 have found that the asteroid not only was never heated above 86 degrees Fahrenheit, it also contained dust grains older than the solar system itself.
The evidence from the first study, completed by Japanese scientists, suggested that:
- 1.Asteroid Ryugu accreted some components that originated in the outer Solar System and contained abundant water and organics. The asteroid then traveled to the inner Solar System.
- 2.Organics associated with coarse-grained phyllosilicates may serve as one of the potential sources of water and organics to the Earth.
The second study, using samples provided to American scientists, found two tiny dust grains that must have come from the material that existed before the formation of our solar system.
The team detected all the previously known types of presolar grains—including one surprise, a silicate that is easily destroyed by chemical processing that is expected to have occurred on the asteroid’s parent body. It was found in a less-chemically-altered fragment that likely shielded it from such activity.
This is not the first discovery of presolar grains, but their delicate existence in Ryugu confirms the conclusions of the first study, that Ryugu had to have formed in the outer solar system and then migrated inward over eons.
The second study also reviewed the make-up of the sample and concluded that Ryugu appears to most closely match the family of carbonaceous Ivuna-type (CI) chondrites, thought to be among the most primitive asteroids known, of which very few have been studied because of they rarely survive the journey through the Earth’s atmosphere.
