AFP, published on Monday 10 August 2020 at 19:36
The dwarf planet Ceres, whose mysteries scientists are struggling to unravel, could be “an oceanic world” where liquid water flows beneath its surface, according to a series of studies published Monday.
Since its discovery in 1801, Ceres has been considered a planet in its own right, then an asteroid and now a dwarf planet. But whatever its name, it has never ceased to intrigue scientists.
In 2015, after a journey of seven and a half years, the American probe Dawn was placed in orbit around this enigmatic sphere located between Mars and Jupiter, in the solar system. It was the first visit of an automatic vessel around such a celestial body.
With its diameter of about 950 km, Ceres represents the largest object in the asteroid belt. It takes the equivalent of 4.61 Earth years to circle the Sun.
Since the end of 2018, the Dawn probe, lacking fuel, has not transmitted anything to researchers, but the latter continue to analyze the incredible images and data it has collected. Work described Monday in seven studies published in the journals Nature Astronomy, Nature Geoscience and Nature Communications.
One of the famous mysteries of Ceres is the presence of more than 130 luminous zones on its surface, most of them associated with impact craters.
But in its final phase, Dawn orbited just 35 km from Ceres, focusing precisely on Occator, one of its 20 million year old craters.
According to the authors of one of the studies, led by Carol Raymond of the California Institute of Technology in the United States, a large reservoir of brine, an aqueous solution saturated with salt, is hiding under the crater.
In another article, Maria Cristina De Sanctis of the National Institute of Astrophysics in Italy and her colleagues report the presence of hydrated sodium chloride on the largest bright area of the Occator crater.
For Maria Cristina De Sanctis, “these results reveal that there is water in a liquid state under the surface of the planet” and that Ceres is “a kind of oceanic world, like certain moons of Saturn and Jupiter “.
“The material found on Ceres is extremely important in terms of astrobiology” because “we know that these minerals are all essential for the emergence of life,” she told AFP.