Skip to main content

The bright spots on Ceres are made of salt, researchers say

The bright spots on Ceres are made of salt, researchers say

/

New information and new questions about the dwarf planet

Share this story

If you buy something from a Verge link, Vox Media may earn a commission. See our ethics statement.

We've been wondering about those bright, white spots on the dwarf planet Ceres ever since the Dawn spacecraft arrived there in March. Speculation was all over the map: many people's gut reaction said water ice, others fantasized about ice volcanoes (or Death Stars). With each passing month (and subsequent image release), the answer seemed to be some sort of salt. But scientists working with the spacecraft's measurements have remained relatively tight-lipped on the subject, waiting for Dawn to inch closer and closer to the surface of Ceres before making a call.

Today, two different papers were published in the journal Nature. One, led by Andreas Nathues from the Max Planck Institute for Solar System Research, claims that the bright areas (of which there are more than 100) contain a magnesium sulfate called hexahydrite. Over time, asteroids impacted Ceres' surface and exposed a subsurface layer made of briny water-ice, Nathues' team claims. The hexahydrite, a salty substance that's of the same ilk as Epsom salt, is just the residue that remains after the exposed water-ice evaporates.

The other paper sheds light on Ceres' origins. In it, the Dawn spacecraft's own science team make the case for the presence of ammonia-rich clays on Ceres. But unlike the bright spots being salt, this bit is more counterintuitive, and raises new questions. Ceres lives between Mars and Jupiter, but it may have formed in the outer Solar System

Ceres currently orbits the Sun in between Jupiter and Mars, but the presence of ammonia-rich clays hints that the 584-mile wide body might have formed in the outer solar system. This is because the ammonia ice that's found in the clay would have evaporated too quickly and probably wouldn't still be here had Ceres formed in the inner solar system. So it's likely that Ceres took a wrong turn somewhere and simply wound up stuck in the orbit we found it occupying. (And if that's not the case, then it may have formed nearby and accreted the ammonia-rich material as it drifted in from the outer solar system, the team says.)

One of the reasons why so many people guessed that the bright spots were made of ice was their apparent reflectiveness. But these spots (especially the now famous ones in the Occator crater, seen above in enhanced color) appear to be so bright in part because the rest of Ceres is very dark, similar in reflectiveness to asphalt. As of now, there is no concrete evidence of water-ice, but the scientists continue to look. Dawn is now in its closest orbit around Ceres, ringing the dwarf planet at an altitude of 240 miles, so more definite answers to these questions could come soon after the next set of observations, scheduled for later this month.

Today’s Storystream

Feed refreshed Sep 25 Not just you

E
Twitter
Emma RothSep 25
Rihanna’s headlining the Super Bowl Halftime Show.

Apple Music’s set to sponsor the Halftime Show next February, and it’s starting out strong with a performance from Rihanna. I honestly can’t remember which company sponsored the Halftime Show before Pepsi, so it’ll be nice to see how Apple handles the show for Super Bowl LVII.


E
Twitter
Emma RothSep 25
Starlink is growing.

The Elon Musk-owned satellite internet service, which covers all seven continents including Antarctica, has now made over 1 million user terminals. Musk has big plans for the service, which he hopes to expand to cruise ships, planes, and even school buses.

Musk recently said he’ll sidestep sanctions to activate the service in Iran, where the government put restrictions on communications due to mass protests. He followed through on his promise to bring Starlink to Ukraine at the start of Russia’s invasion, so we’ll have to wait and see if he manages to bring the service to Iran as well.


E
External Link
Emma RothSep 25
We might not get another Apple event this year.

While Apple was initially expected to hold an event to launch its rumored M2-equipped Macs and iPads in October, Bloomberg’s Mark Gurman predicts Apple will announce its new devices in a series of press releases, website updates, and media briefings instead.

I know that it probably takes a lot of work to put these polished events together, but if Apple does pass on it this year, I will kind of miss vibing to the livestream’s music and seeing all the new products get presented.


E
External Link
Emma RothSep 24
California Governor Gavin Newsom vetoes the state’s “BitLicense” law.

The bill, called the Digital Financial Assets Law, would establish a regulatory framework for companies that transact with cryptocurrency in the state, similar to New York’s BitLicense system. In a statement, Newsom says it’s “premature to lock a licensing structure” and that implementing such a program is a “costly undertaking:”

A more flexible approach is needed to ensure regulatory oversight can keep up with rapidly evolving technology and use cases, and is tailored with the proper tools to address trends and mitigate consumer harm.


Welcome to the new Verge

Revolutionizing the media with blog posts

Nilay PatelSep 13
A
Youtube
Andrew WebsterSep 24
Look at this Thing.

At its Tudum event today, Netflix showed off a new clip from the Tim Burton series Wednesday, which focused on a very important character: the sentient hand known as Thing. The full series starts streaming on November 23rd.


A
The Verge
Andrew WebsterSep 24
Get ready for some Netflix news.

At 1PM ET today Netflix is streaming its second annual Tudum event, where you can expect to hear news about and see trailers from its biggest franchises, including The Witcher and Bridgerton. I’ll be covering the event live alongside my colleague Charles Pulliam-Moore, and you can also watch along at the link below. There will be lots of expected names during the stream, but I have my fingers crossed for a new season of Hemlock Grove.


T
Twitter
Tom WarrenSep 23
Has the Windows 11 2022 Update made your gaming PC stutter?

Nvidia GPU owners have been complaining of stuttering and poor frame rates with the latest Windows 11 update, but thankfully there’s a fix. Nvidia has identified an issue with its GeForce Experience overlay and the Windows 11 2022 Update (22H2). A fix is available in beta from Nvidia’s website.