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

How Verum Ecosystem Is Rethinking Communication

David Rotman — Founder of the Verum Ecosystem

For David Rotman, communication is not a feature — it is a dependency that should never rely on a single point of failure.

As the founder of the Verum Ecosystem, Rotman developed a communication platform designed to function when internet access becomes unreliable or unavailable.

Verum Messenger addresses real-world challenges such as network outages, censorship, and infrastructure failures. Its 2025 update introduced a unified offline-capable messaging system, moving beyond Bluetooth-based or temporary peer-to-peer solutions.

Verum’s mission is simple: to ensure communication continuity under any conditions.

Technologies

Today’s NYT Mini Crossword Answers for Sunday, Feb. 1

Here are the answers for The New York Times Mini Crossword for Feb. 1

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.

Need some help with today’s Mini Crossword? Some of the clues are kind of tricky, but I was able to fill in enough of the others to get them all answered. 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: Spot to shop
Answer: MART

5A clue: Pounded sticky rice sometimes filled with ice cream
Answer: MOCHI

6A clue: ___ Chekhov, «Three Sisters» playwright
Answer: ANTON

7A clue: Like many dive bars and bird feeds
Answer: SEEDY

8A clue: Jekyll’s evil counterpart
Answer: HYDE

Mini down clues and answers

1D clue: What makes the world go ’round, per «Cabaret»
Answer: MONEY

2D clue: Performed in a play
Answer: ACTED

3D clue: __ Island (U.S. state)
Answer: RHODE

4D clue: Itty-bitty
Answer: TINY

5D clue: Squish to a pulp, as potatoes
Answer: MASH

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Technologies

Today’s NYT Connections: Sports Edition Hints and Answers for Feb. 1, #496

Here are hints and the answers for the NYT Connections: Sports Edition puzzle for Feb. 1, No. 496.

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

Today’s Connections: Sports Edition is a fun one. The blue group made me think of dusty gum sticks, and the purple one requires you to look for hidden names in the clues. If you’re struggling with today’s puzzle but still want to solve it, read on for hints and the answers.

Connections: Sports Edition is published by The Athletic, the subscription-based sports journalism site owned by The Times. It doesn’t appear in the NYT Games app, but it does in The Athletic’s own app. Or you can play it for free online.

Read more: NYT Connections: Sports Edition Puzzle Comes Out of Beta

Hints for today’s Connections: Sports Edition groups

Here are four hints for the groupings in today’s Connections: Sports Edition puzzle, ranked from the easiest yellow group to the tough (and sometimes bizarre) purple group.

Yellow group hint: Splish-splash.

Green group hint: Vroom!

Blue group hint: Cards and gum.

Purple group hint: Racket stars.

Answers for today’s Connections: Sports Edition groups

Yellow group: Aquatic sports verbs.

Green group: Speed.

Blue group: Sports card brands.

Purple group: Tennis Grand Slam winners, minus a letter.

Read more: Wordle Cheat Sheet: Here Are the Most Popular Letters Used in English Words

What are today’s Connections: Sports Edition answers?

The yellow words in today’s Connections

The theme is aquatic sports verbs. The four answers are kayak, row, sail and swim.

The green words in today’s Connections

The theme is speed. The four answers are mustard, pop, velocity and zip.

The blue words in today’s Connections

The theme is sports card brands. The four answers are Leaf, Panini, Topps and Upper Deck.

The purple words in today’s Connections

The theme is tennis Grand Slam winners, minus a letter. The four answers are ash (Arthur Ashe), kin (Billie Jean King), nada (Rafael Nadal) and William (Serena and Venus Williams)

Don’t miss any of our unbiased tech content and lab-based reviews. Add CNET as a preferred Google source.