Skip to Content
Space

The dwarf planet Ceres might be home to an underground ocean of water

The largest asteroid in the solar system seems to have a salty ocean of water sitting deep beneath its surface.
August 11, 2020
ceres water
ceres water
Highlights of the salt deposits at the Occator Crater on Ceres.NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Ceres, the largest asteroid in the solar system, seems to have liquid water seeping onto its surface, according to a new paper in Nature Astronomy. Data from NASA’s Dawn orbiter, the study suggests, show signs that it may be harboring an ocean deep underground. 

The background: Ceres, a dwarf planet located in the asteroid belt between Mars and Jupiter, was studied intensely by the Dawn orbiter from March 2015 to November 2018. In its final weeks, the orbiter came as close as 22 miles from Ceres’s surface and collected a tremendous amount of data about the dwarf planet’s chemical composition. Dawn found many sodium chloride deposits on the surface, which scientists thought likely came from liquid that had seeped up onto the surface and evaporated, leaving behind a salty crust.

What’s new: But there still remained a question of exactly how that liquid got there. In a new analysis of the high-resolution images Dawn collected during those last weeks, Italian researchers found that the liquid comes from an underground reservoir of briny water, 25 miles below the surface of the Occator Crater, that could measure hundreds of miles wide. The salts found on the surface are important in helping to maintain liquid water within an environment like Ceres. 

The findings are being published along with other papers looking into new insights into Ceres and the geology around its Occator Crater, which has a diameter of 57 miles (92 kilometers) and is roughly 20 million years old. Some of that research also teased the presence of water at the crater in other ways, like conical hills that are similar to icy mountains on Earth formed by pressurized groundwater, but the salt deposits offer the best evidence.

So what? The salt deposits are young—some just a couple of million years old. And the Dawn data shows that the dehydrated salts actually still have a bit of water in them. That suggests whatever geological activity is encouraging these deposits might still be happening, which would mean Ceres is still an active world.

Although salty water can be an extreme environment, the presence of an ocean suggests there might be more of these briny water reservoirs located elsewhere on the dwarf planet, raising hopes Ceres was once a habitable world—and might still be. 

Deep Dive

Space

Illustration of DART
Illustration of DART

NASA is going to slam a spacecraft into an asteroid. Things might get chaotic.

A new simulation shows that when the DART mission hits the target asteroid, it could send it spinning and wobbling in a dramatic way.

spacex starlink
spacex starlink

Who is Starlink really for?

The boom in LEO satellites will probably change the lives of customers who’ve struggled for high-speed internet—but only if they can afford it.

crew of Inspiration 4 mission
crew of Inspiration 4 mission

Netflix’s SpaceX docuseries misses the mark on Inspiration4

"Countdown" is an exclusive dive into the first all-civilian mission into orbit, but it spends too much time as a free advertisement for SpaceX.

Saturn colored rings
Saturn colored rings

Saturn’s insides are sloshing around

A new paper suggests Saturn’s core is more like a fluid than a solid, and makes up more of the planet’s interior than we thought.

Stay connected

Illustration by Rose WongIllustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at customer-service@technologyreview.com with a list of newsletters you’d like to receive.