- A NASA spacecraft has discovered that a saltwater ocean lies deep below the surface of Ceres, a dwarf planet in the asteroid belt between Mars and Jupiter.
- New research shows that glossy salt deposits on the surface of Ceres were left behind by water percolated from underground.
- Ceres may once have early life, scientists say, because of its recent geological activity, the presence of water, minerals that contain ingredients for life, and a possible warm period in its past.
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A NASA spacecraft has just discovered a hidden ocean in our solar system.
The agency’s probe Dawn orbited the dwarf planet Ceres, which sits in the asteroid belt between Mars and Jupiter for three years, orbiting before it was fueled in 2018. At one point, Dawn traveled 22 miles, or 35 kilometers, above the surface of the small world. Scientists are still examining the data it collects, as it provides a close look at some bright regions on Ceres that have been scratching their heads for years.
Dawn already helped researchers learn that those shiny spots were covered in a compound called sodium carbonate, which is made up of sodium, carbon, and oxygen. That salt crust probably came from liquid that evaporated on the surface of Ceres.
A view of a spaceship artist Dawn flying past Ceres.
NASA / JPL-Caltech
But where the liquid escaped remained a mystery until Monday, when a series of papers finally said that salt water had percolated to the surface of the dwarf planet from an underground reservoir, about 25 miles deep and hundreds of miles wide.
“This elevates Ceres to ‘ocean world’ status,” Carol Raymond, chief investigator for the Dawn mission, told Reuters.
This places the dwarf planet in the company of Enceladus (an icy moon of Saturn) and Europe (an icy moon of Jupiter) – other worlds with oceans under the ground. Like her, Ceres is now a competitor to foreign life.
“The material found on Ceres is extremely important in terms of astrobiology,” Maria Cristina De Sanctis, a researcher at the Istituto Nazionale di Astrofisica in Rome, told The Guardian. “We know that these minerals are all essential for the emergence of life.”
The ocean of Ceres could be the relic of a warmer era
The clear regions that Dawn studied are located in the Occater crater of Ceres – the salt deposits are called the Cerealia Facula and Vinalia Faculae. They are just 2 million years old, and Dawn researchers think that the geological process that made them continues.
But the forces that allow Enceladus and Europe to maintain their oceans are not the same for Ceres. The other two ocean worlds feel a strong gravitational pull from their planets: As they orbit Saturn and Jupiter, those massive bodies stretch the moons, building friction that heats the moons from within.
A fracture network on the floor of the Occator crater, photographed by NASA’s Dawn spacecraft on July 26, 2018, at an altitude of about 94 miles, or 152 kilometers.
NASA / JPL-Caltech / UCLA / MPS / DLR / IDA
But in the case of Ceres, asteroid influence may have played a role.
“For the large deposit at Cerealia Facula, most of the salt was supplied from a slushy area just below the surface that was melted by the heat of the impact that formed the crater about 20 million years ago,” Raymond said. released in a NASA press release. “The impulse flow subsided after a few million years; however, the impact also created large fractures that could penetrate the deep, long-lived reservoir, allowing brine to continue percolating to the surface.”
In other words, asteroid effects may have kept the dwarf planet warm enough for liquid water to stay below its surface. Scientists think the groundwater they discovered via Dawn may be a surviving tube of a global ocean that freezes as Ceres cools.
In the short period when conditions were warm enough, life could have arisen.
“The chances of finding life in another world remain high,” NASA Director Jim Bridenstine said. Twitter. “Ceres is the latest proof that our solar system is full of ancient habitable environments.”
