The asteroid Ceres, once thought to be just a huge orbiting rock between Mars and Jupiter, has slushy volcanoes and seawater beneath its surface that could have formed underwater underground, suggests new research .
The research is part of seven Ceres studies using data from the spacecraft of NASA Dawn robots, published Monday in the journals Nature Astronomy, Nature Geoscience and Nature Communications. Two of the studies indicate that a bright spot on the large crater of the Occator of Ceres was caused by the outflow of salt water from the fractures in the rotten crust.
That suggests that Ceres has buried saltwater reservoirs and may even have an ocean floor.
“Ongoing activity in Occator brings additional and independent evidence for a deep layer of brine, and Ceres has been upgraded to the land of the ocean worlds,”; wrote Die mission scientist Julie Castillo-Rogez of NASA’s Jet Propulsion Laboratory in Pasadena, California, in a general publication published in Nature Astronomy.
Although Saturn’s moon Enceladus and Jupiter’s moon Europe are thought to have subsurface oceans, they are both warmer than the almost-frozen saltwater reservoirs at Ceres. But the frozen dwarf planet Pluto could also have a subsurface ocean, and new Ceres studies could have implications for future investigations of magical worlds, he said.
The Ceres, currently nearly 200 million miles from Earth, are the largest object in our system’s basic aster belt. It is about 600 miles across, with enough gravity to pull it into a rough sphere.
Under the rules of the International Astronomical Union, which makes Ceres a dwarf planet – perhaps the only dwarf planet closer than Pluto.
The NASA Dawn probe was launched in 2007 and spent many years traveling on the asteroid belt with its slow but extremely efficient ion engine. From 2011 to 2012, it orbited the asteroid Vesta – the second largest object in the asteroid belt at 320 miles.
Dawn arrived in Ceres in 2015 and studied it until 2018, orbiting within 25 miles of the asteroid surface before it ran out of fuel.
Early Ceres studies using Dawn mission data suggested it had an outstanding saltwater layer, and the latest study reinforced that idea, Jet scientist scientist Carol Raymond told Jet. Propulsion Laboratory, the leading author of one of the studies.
“The more data we get, the clearer it becomes that there is geologic activity,” Raymond said. “Some liquids have come to the surface quite recently.”
Another study led by planetary scientist Maria Cristina De Sanctis of the National Institute of Astrophysics in Italy identified the bright spot on the Occitor crater as containing a form of sodium chloride – table table – salt salt – chemically bind to molecules of water.
That chemical form quickly passed, leading scientists to conclude that it was “very recent” in geological time, De Sanctis said.
“It could have been 100,000 years ago, or a thousand years ago, or even last week,” he said.
Another study translated some other bright areas in Ceres as evidence of “cryovolcanoes” allowing freezing salt water from crust reservoirs to drip to the surface.
Taken together, studies suggest that Ceres is an active world – although it is extremely cold, with temperatures of almost minus 100 degrees Fahrenheit in sunlight.
Buried reservoirs, more than eight times saltier than the oceans on Earth, are thought to start about 25 miles below the crust and have temperatures of about minus 31 degrees Fahrenheit – warm enough to have consistency of muddy mud, but too cold for life to thrive.
But Ceres is more interesting than anyone expected, and scientists are pushing for a second investigation to follow Dawn into the asteroid.
“I enjoyed watching Vesta and I was sad to go to Ceres, because I thought it was dark and boring,” De Sanctis said. “But no – it’s really exciting.”
The idea that Ceres had a buried saltwater layer is controversial, however, and some scientists think the latest studies are not conclusive.
“There is no solid evidence for a previous ocean in Ceres based on the papers,” said geochemist planet Mikhail Zolotov of Arizona State University in Tempe.
“The presence of hydrated silicates and local salts on the surface suggests contact with water-rock in the history of Ceres, but not necessarily an ocean,” he said in an email. “Even if there is an ocean, it should be undressed early in Ceres history.”
But others are hotter on the idea.
“I have always been convinced that Ceres holds subsurface fluid,” said astrophysicist Steven Desch, also of Arizona State University.
“These papers … prevent the compositions of liquids and the order in which they are released on the surface,” he said in an email. “This is a fascinating detailed timeline of brine-driven cryovolcanism in Ceres.”