Technologies

Jupiter’s Moon Callisto Has a Whole Lot of Oxygen Scientists Struggle to Explain

A recent analysis finds up to 1,000 times more molecular oxygen than can be explained by prevailing theories about where it comes from.

Jupiter’s four largest moons are some of the solar system’s most compelling worlds. Io is dotted with active volcanoes, and Europa hides a subsurface ocean many want to check for alien life. Ganymede is the largest moon in the solar system, and Callisto is the system’s most heavily cratered object. Callisto is also home to an emerging mystery: The moon’s thick atmosphere holds a surprising amount of oxygen, and scientists aren’t sure why.

Observers have known about the presence of abundant molecular oxygen at Callisto for a while, with the working assumption being that the influence of Jupiter’s powerful magnetosphere could be knocking molecules of water, hydrogen and oxygen out from Callisto’s icy surface and into the atmosphere.

But when a team of researchers ran the numbers, they found that Jupiter’s magnetism can’t fully explain the amount of molecular oxygen around Callisto.

«There’s a huge discrepancy,» said Shane Carberry Mogan, lead author on a paper about the findings published late last month in the journal JGR Planets. «We were off by something like two orders of magnitude to even three orders of magnitude.»

For the layperson, that means there is 100 to 1,000 times as much molecular oxygen present in Callisto’s atmosphere as the scientists would expect to find if Jupiter’s magnetosphere stripping it out of the icy surface were the sole source.

The discovery of so much oxygen on an alien world may sound like a boon for the possibility that Callisto may support life, but the frozen world is probably far too cold for life as we know it. That said, plentiful oxygen could be useful in generations to cometo explorers who may be able to use it for fuel and life support while traveling around deep space.

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It isn’t clear what’s happening at Callisto to produce so much oxygen, but Carberry Mogan hopes to get a better understanding of processes active in the moon’s surface that may yield an explanation or clues.

«That’s probably Callisto’s most enigmatic feature is its surface,» said Carberry Mogan, who’s a postdoctoral researcher in planetary science at the University of California at Berkeley. «It’s supposed to be an icy body, but when you look at it, it’s mostly this dark surface, anywhere from millimeters to kilometers deep.»

It’s still up for debate whether Callisto’s surface is more rock or ice. The dark material on its surface could also be ice-rich, providing a plentiful source for the mysterious amount of oxygen in the atmosphere.

For help with the mystery, Carberry Mogan is looking to upcoming robotic missions like ESA’s Juice and NASA’s Europa Clipper, which may swing close enough to Callisto to gather new data that could shed light on the puzzle.

«It’s really perplexing,» he said. «The next step is to figure out why there’s this gap between the source [of oxygen] and the observation.»

Technologies

Ring Finally Goes Wire-Free for Its Latest 4K Video Doorbells

The launch of battery-powered versions of the company’s powerful AI doorbells has been highly anticipated.

Security company Ring on Wednesday announced a significant expansion of its video doorbell line, notably battery-powered versions of both its 4K and 2K models, priced from $80.

Both Amazon’s Ring and Google Nest debuted high-resolution video doorbells with new AI features in the fall of 2025. But they were wired only, and in my tests, I kept thinking, «I sure wish there were battery models available.»

Wireless video doorbells are far better for most front doors than models that require connecting to your existing doorbell wiring, which is often poorly positioned for a security camera. Mine, for example, is located on a wall beside my door that’s useless for any kind of video views, no matter how you angle a lens.

«Enhancing image quality in battery-powered doorbells means customers can enjoy reliable performance with the flexibility to install devices in a way that suits their space, whether renting or living in homes without existing wiring,» a Ring spokesperson said.

At first, I wondered whether the higher 4K resolutions and more advanced AI features would use too much power to support batteries. If so, Ring is the first to fix that issue with this suite of doorbells, including these models available for preorder right now:

Ring Battery Doorbell Pro — $250: This model offers up to 4K resolution and 10x zoom, and Ring says it features a redesigned internal architecture to support battery power.
Ring Battery Doorbell Plus (2nd-gen) — $180: This model includes a quick-release battery pack along with 2K video.
Ring Battery Doorbell (2nd-gen) — $100: This video doorbell includes 2K video, a 6x zoom and what Ring calls a «streamlined, rechargeable design,» which means you take the entire video doorbell to charge it, not just the battery — a design I greatly prefer, since Ring’s battery packs can get fiddly.

There’s also a new version of a Ring wired doorbell with 2K resolution, starting at $80. It wouldn’t be Ring without a plethora of doorbell devices to confuse newcomers, which is why I have a guide specifically for Ring video doorbells that will need some updating once I finish testing these new models.

Resolution plus an intelligence upgrade

Ring’s ordinary subscriptions of the Ring Protect plan give you cloud video storage and intelligent alerts for people, packages and vehicles, which are important but not really advanced AI. But spring for the $20-per-month Ring AI Pro cam, and this new generation of cameras opens up other capabilities.

Ring’s AI features include AI video descriptions, so if you get an alert, you can also get a summary of what the doorbell saw, including people and activities. A similar feature lets you search your video history with specific terms, such as «bike,» «truck» and so on. You also get the beta version of Ring’s Familiar Faces feature, which can ID logged faces of people who approach.

If these AI features make you uneasy and you’d rather protect your privacy, the best option is to avoid a subscription altogether or choose a lower-tier plan that gives you cloud storage without AI.

I also have a guide on how to turn off Ring’s detection and data-sharing features that might make you nervous, so you can keep what you like while ditching what you don’t.

Technologies

Today’s NYT Mini Crossword Answers for Thursday, March 26

Here are the answers for The New York Times Mini Crossword for March 26.

Looking for the most recent Mini Crossword answer? Click here for today’s Mini Crossword hints, as well as our daily answers and hints for The New York Times Wordle, Strands, Connections and Connections: Sports Edition puzzles.

Baseball is back! You’ll see baseball images patterned throughout today’s Mini Crossword grid, and when you solve the puzzle, they’ll spell out a certain word. Play ball! Er, read on for all the answers. And if you could use some hints and guidance for daily solving, check out our Mini Crossword tips.

If you’re looking for today’s Wordle, Connections, Connections: Sports Edition and Strands answers, you can visit CNET’s NYT puzzle hints page.

Read more: Tips and Tricks for Solving The New York Times Mini Crossword

Let’s get to those Mini Crossword clues and answers.

Mini across clues and answers

1A clue: Degrees for boardroom execs
Answer: MBAS

5A clue: «___ want for Christmas …»
Answer: ALLI

6A clue: What Hamlet holds while giving his «Alas, poor Yorick!» speech
Answer: SKULL

7A clue: Wild, as an animal
Answer: FERAL

8A clue: Sphere
Answer: ORB

Mini down clues and answers

1D clue: Word after «match» or «mischief»
Answer: MAKER

2D clue: Bit of writing on a book jacket
Answer: BLURB

3D clue: Penne ___ vodka
Answer: ALLA

4D clue: Window ledge
Answer: SILL

6D clue: Bay Area airport, for short
Answer: SFO

Technologies

McDonald’s KPop Demon Hunter Meals Include Bright Purple Nugget Sauce

The Derpy McFlurry mixes popping boba pearls and berry sauce into a soft-serve dessert.

McDonald’s has seen success with themed combo meals, including its holiday Grinch Meal. Now, the fast-food chain is capitalizing on Netflix’s Oscar-winning animated film, KPop Demon Hunters, with new upcoming menu items and both a breakfast meal and a lunch/dinner offering. Let’s hope you like the color purple.

The HUNTR/X Meal, named for the K-pop girl group in the movie, is a 10-piece chicken McNuggets meal that includes a medium drink and three special menu items.

Ramyeon McShaker fries come with a small bag of soy, garlic, sesame and spice seasoning, along with regular McDonald’s french fries. You sprinkle the seasoning into the provided bag, dump in the fries, shake it all up and eat.

The meal includes two new sauces for the fries and nuggets. Hunter sauce is a sweet chili sauce mixing notes of chili, garlic and pepper. But my favorite item on this new menu is Demon sauce, a bold mustard sauce with some heat and a bold purple color. There’s just not enough dark purple food out there.

There’s also a new dessert, the Derpy McFlurry, which blends creamy vanilla soft serve with berry-flavored popping boba pearls, served with a swirl of wild berry sauce. McDonald’s named it for the supernatural feline, Derpy Tiger, from the movie.

If breakfast is your bag, the new morning meal is the Saja Boys Breakfast Meal, named for the movie’s boy band.

It includes a Spicy Saja McMuffin sandwich, which is a sausage McMuffin with egg and a spicy Saja sauce, hash browns and a small drink.

Both meals come with a photocard for one of the bands and a Derpy card. The Derpy card includes a QR code you can scan to unlock online content about the film.

The full KPop Demon Hunters menu should be available at participating McDonald’s beginning March 31.

The McDonald’s Grinch meal (and its accompanying patterned socks) sold out quickly, so KPop Demon Hunters fans may want to mark their calendars and nab a meal when they are released.