The long, puzzling dwarf planet Ceres, in reality the first named asteroid, has surface features that are much more complex than previously thought. Or at least that’s the conclusion of a recent paper given at the recent European Geosciences Union 2026 General Assembly in Vienna.

New data analysis from NASA’s Dawn mission points to a surface with steep slopes, fractures, and albedo variations complicating crater identification.

In fact, Ceres has perplexed astronomers since its discovery in 1801 by Italian astronomer Giuseppe Piazzi. Yet in 2006, it was controversially reclassified as a dwarf planet, primarily due to its large size and differentiated interior. That is, unlike most asteroids, Ceres has a core, a mantle, and a crust. Some astrobiologists posit that the dwarf planet may have even once developed primitive microorganisms.

Even if so, Ceres was never an astrobiological Valhalla. About a quarter of the size of our moon, Ceres itself only spans about 960 km in diameter. But due to its unique internal history and composition, it remains scientifically compelling.

Toward the end of the Dawn mission, a detailed re-examination of the gravity field in the Occator crater region revealed a gravity anomaly at a depth of some 50 km, Alicia Neesemann, a remote sensing analyst and planetary scientist at Freie Universitat Berlin, told me in Vienna.

This anomaly indicates the presence of less dense material, interpreted as a subsurface reservoir of brines (salty water), says Neesemann. These brines likely ascended through subsurface fractures created by the Occator impact and erupted at the surface, with their remnants visible today as the evaporite deposits Cerealia Facula and Vinalia Facula, she says.

The Occator impactor slammed into Ceres an estimated few million years to 20 million years ago creating an irregular crater some 92 km wide.

By a wide margin, Occator is the youngest crater of its size on Ceres, says Neesemann. The exposure of these carbonate deposits such as the cryovolcano Cerealia Facula is the result of a young, large impact coinciding with a subsurface brine reservoir, she says.

Ceres has this unique high-water content of about 25 percent.

After Dawn visited Ceres and after we analyzed all the data, it became clear that it might have had a subsurface ocean in its past, says Neesemann.

Bright Surface Deposits

The bright deposits of Cerealia Facula within Occator Crater on Ceres are key indicators of recent endogenic activity, most likely linked to cryovolcanic and hydrothermal processes and the presence of subsurface brines, Neesemann and her co-authors write. Constraining the absolute model age of these deposits is essential for understanding the geologic evolution of Occator and the thermal history of Ceres, they note.

A salty subsurface brine pocket lowers the freezing point of water, so that water could still ascend to the surface, says Neesemann. It’s ice and water driven volcanism that could have reached the surface, she says.

How does cryovolcanism differ from regular volcanism?

Classic volcanism that happens under very high thousand degree temperatures, BUT on Ceres, cryovolcanism takes place at temperatures well below zero. A cryovolcano is usually volcanism based on water and salt water mixtures, and not on based on silicates or iron.

Such large impacts generate a lot of heat which often creates impact melt in the subsurface. This is likely responsible for allowing this brine water to ascend to the surface in the form of cryovolcanic eruptions.

*NASA image of the Occator crater on the dwarf planet Ceres which has been rotated to change the position of the shadows and eliminate the crater illusion. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA via Wikipedia*

Could microfossils on Ceres still be preserved?

In the unlikely scenario that microorganisms had formed within the brine pocket at 50 km depth, I would expect them to have been mechanically destroyed or chemically altered beyond recognition during ascent and surface exposure, says Neeseman.

Ceres’ surface continues to be bombarded by smaller meteorites in an ongoing process known as impact gardening. It’s analogous to how our Moon’s surface has been pulverized into a fine, powdery regolith.

Even so, Neesemann is part of a topography working group for a potential NASA JPL Ceres sample return mission equipped with an orbiter and lander.

The orbiter will first take even higher resolution images than the Dawn mission, says Neeseman. That’s because we really need to know, if it’s safe to land on these bright deposit areas, she says.

But Neesemann remains confident about such a mission.

As she points out, Ceres’ surface gravity is 5.7 times less than the Moon. But it’s still significantly higher than that of asteroids like Bennu or Ryugu, on which successful landings have already been achieved.

So, sampling Ceres would be more akin to a planetary mission than a typical asteroid sample-return mission, says Neesemann.

Sources

EGU26 Neeseman

Alicia Neesemann

To vote in person, Californians, you have until Tuesday at 8 p.m. to get to a voting center and cast your ballot in the California 2026 primary election.

Here’s what else you need to know about in-person voting for what has been a volatile, surprising election.

You can register to vote on election day. Here’s how

You can still register to vote on or before election day as a “conditional voter” through the same-day voter registration process.

Eligible citizens who need to register or re-register to vote within 14 days of an election can complete this process at a county elections office, polling place or vote center.

Your submitted ballot will be processed and counted once the county elections office has completed the verification process.

Where to find in person voting near you

You can find your nearest polling place from the California secretary of state’s website here.

In Los Angeles County, you can use the county’s vote center locator on the registrar-recorder/county clerk’s website here.

Hours of operation for vote centers

From May 23 to June 1, in-person voting centers are open from 10 a.m. to 7 p.m.

On June 2, election day, vote centers are open from 7 a.m. to 8 p.m. across the state.

You can submit your vote-by-mail ballot at a vote center

If you filled out your vote-by-mail ballot, walk into a vote center and ask a poll worker where you can submit your mailed ballot.

You can drop off a ballot for someone besides yourself as long as you’ve been authorized to do so and you’re not getting paid on a per-ballot basis, according to the secretary of state.

What to bring to your polling place as a first-time voter

In most cases, you’re not required to show identification to a polling place worker before casting a ballot.

However, if you are voting for the first time after registering to vote by mail and did not provide your driver’s license number, state identification number or the last four digits of your Social Security number on your registration form, you may be asked to show a form of identification at the polls, according to the secretary of state.

In this scenario, you’ll need to bring both of the following:

• a driver’s license or state identification number
• the sample ballot booklet you received from your county elections office

Other acceptable forms of identification include:

• your passport
• your student identification showing your name and photograph
• a utility bill
• a bank statement

A complete list of acceptable forms of voter identification to use when voting in person for the first time can be found here. If you have any questions, you can call the secretary of state’s toll-free voter hotline at (800) 345-8683.

What regular voters should bring to the vote center

The League of Women Voters of California, a nonpartisan organization that works to protect and expand voter rights, advises that you bring to the voting center the ballot that was mailed to you.

If you didn’t bring your mailed ballot, some counties will require you to vote using a provisional ballot that will be counted once elections officials check that you are eligible.

• Check in with your local county elections office to understand your county’s policy. In Los Angeles County, you can call the registrar-recorder/county clerk’s office at (800) 815-2666 for more information.
• If you live in a “Voter’s Choice” county — where voters can choose how, when and where to cast their ballot — you can get a regular ballot at any voting center. Participating counties include: Alameda, Amador, Butte, Calaveras, El Dorado, Fresno, Humboldt, Imperial, Kings, Los Angeles, Madera, Marin, Mariposa, Merced, Napa, Nevada, Orange, Placer, Riverside, Sacramento, San Benito, San Diego, San Mateo, Santa Clara, Santa Cruz, Sonoma, Stanislaus, Tuolumne, Ventura, and Yolo.

Checking in at a vote center in Los Angeles County

Local elections officials say you can save time checking in at the vote center by scanning your “quick check-in code,” which verifies your voter registration.

The code can be found on your mailed sample ballot and vote center postcard. Take either of those hard copies to the vote center.

You can also get the check-in code by verifying your voter registration here. You’ll need to input your last name, birth date, the house number of your residential address and your ZIP Code. For assistance call, (800) 815-2666, Option 2.

How to vote in Los Angeles County

After checking in, a poll worker will lead you or point you to an available digital ballot marking device.

How to use the digital ballot marking device:

1. On the touch screen, you will click on the “tap to begin” button and then choose your preferred language.
2. You’ll then be prompted to insert your ballot. The screen will say “ballot loaded,” and then you’ll begin the voting process. If you’re having any trouble, flag down a poll worker for help.
3. On the next screen, click on the “I want to start voting” button to make your ballot selections.
4. To see every option for each race or measure, click the “more” button at the bottom of the screen.
5. After clicking on your selection, click the “next” button to get to the next question.
6. Once you’ve completed your ballot, you’ll be able to review your selections; you can hit the “back” button to make any changes.
7. You’ll then hit the “Yes, I am ready to print” button, and your ballot will print. You can also review the printed ballot before turning it in.
8. Follow the instructions of your poll center to submit your printed and completed ballot.