Scientists have found salt minerals in samples of the asteroid Ryugu. This suggests that salt water once existed in its parent body.
Ryugu is a typical 900-meter near-Earth asteroid. Between 2018 and 2019, it was explored by Japan’s Hayabusa-2 mission, which took a sample of its matter and then successfully delivered it to Earth.
Even before scientists began studying Ryugu samples, they suspected that samples might contain substances not normally found in meteorites. These are highly water-soluble materials that can easily react with moisture in the Earth’s atmosphere and are difficult to detect unless examined in their pristine state.
The assumption was confirmed. While examining the samples, a team of researchers from Kyoto University found evidence of salt deposits containing sodium carbonate, halite and sodium sulfates. Their presence suggests that liquid salt water once existed in Ryugu’s mother body.
Experts believed the asteroid was once part of a much larger object that existed about 4.5 billion years ago, shortly after the formation of the Solar System. This parent body must have been heated by radioactive decay, creating an environment with hot water below 100°C.
The salt minerals found in the Ryugu samples were formed in highly saline water and under liquid-limited conditions. Scientists believe that as the cracks carried salt water out into space, or as the mother body cooled, there was less and less of it until it finally evaporated or froze.
The discovery is significant because it provides new evidence for the role that water played in the development of planets and moons in the outer Solar System. Scientists believe that there are still subsurface oceans in the interior of many of them. Sodium carbonate and halite are expected to be found in surface sediments on Ceres, in water plumes from Saturn’s moon Enceladus, and on the surface of Jupiter’s moons Europa and Ganymede.
Recall that the study of a sample of the substance of another asteroid Bennu also showed that in the past it could be part of the water world.
According to Phys.org
