China News Agency, Beijing, August 11 (Reporter Sun Zifa) As the largest known celestial body in the asteroid belt of the solar system, the latest exploration and research of the dwarf planet Ceres has discovered that it is an ocean world.
Springer Nature’s international academic journals "Nature-Astronomy", "Nature-Earth Science", and "Nature-Communications" recently published 7 scientific research papers on the planetary science of the "Dawn" probe close to Ceres. , The second extended observation of Ceres by the "Dawn" mission shows that Ceres is an ocean world and may be geologically active in the recent past, which provides further understanding of the history and formation of this dwarf planet.
The "Dawn" probe was launched 11 years ago. The picture shows the "Dawn" asteroid probe flying in space (computer composite image)
The "Dawn" probe orbited Ceres from 2015 to 2018 until it ran out of fuel. In the final orbiting phase, the "Dawn" probe was only 35 kilometers from the surface of Ceres. The probe’s main observation point is the 20 million-year-old Occator crater, where the probe has discovered bright deposits of brine from the planet’s interior.
In a paper published in "Nature-Astronomy", Carol Raymond of the California Institute of Technology and his colleagues analyzed the high-resolution gravitational data and images sent by the "Dawn" and found that Oka There is a large brine reservoir deep at the bottom of the Tuo crater. They believe that the reservoir may have been under the influence of the forces that caused the formation of the crater, and moved, causing these bright salt deposits on the planet's surface.
In another paper, Maria Cristina De Sanctis and colleagues at the National Institute of Astrophysics in Italy reported the presence of hydrated chloride salts in the center of the largest bright area in the center of the Okato crater. Due to the rapid dehydration of these salts, the author believes that these brines may still be gushing out, which means that there may still be salty liquids inside Ceres.
The picture shows the theoretical path of water molecules on Ceres drawn by scientists. Image source: NASA official website
In the other two papers of "Nature-Astronomy", Ryan Park of the California Institute of Technology and his colleagues studied the crustal composition of Ceres; Andreas Natus of the Max Planck Institute for Solar System Research in Germany Nathues and colleagues pointed out that Ceres started a period of active ice volcanoes about 9 million years ago, and it ended only recently.
In a paper published in "Nature-Earth Science", a study by Britney Schmidt and colleagues from the Georgia Institute of Technology in the United States showed that the hills of the Okato Crater may be caused by the impact of the ice when the flowing water was frozen. Forming. This shows that not only Earth and Mars, Ceres has also experienced active freezing hydrological phenomena in recent geology.
In two papers published in Nature Communications, Paul Schenk and his colleagues found that the water- and salt-rich mud-like impact of lava on Ceres is different from that on Mars, and the scale is also different. Not as good as Mars; US Jet Propulsion Laboratory Jennifer Scully and colleagues used research to show that the various bright deposits in the Okato Crater may have different sources. (Finish)