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.

Here are other moons worth visiting in person

+8 more

See all photos

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

Facebook Brings Back Local Job Listings: How to Apply

One of Facebook’s most practical features from 2022 is being revived by Meta.

On the hunt for work? A Local Jobs search is being rolled out by Meta to make it easier for people in the US to discover and apply for nearby work directly on Facebook. The feature is inside Facebook Marketplace, Groups and Pages, Meta said last week, letting employers post openings and job seekers filter roles by distance, category or employment type.

You can apply or message employers directly through Facebook Messenger, while employers can publish job listings with just a few taps — similar to how you would post items for sale on Marketplace.

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

Facebook offered a Jobs feature before discontinuing it in 2022, pushing business hiring toward its other platforms. Its return suggests Meta is attempting to expand Facebook’s usefulness beyond social networking and to position it once again as a hub for community-driven opportunities.

«We’ve always been about connecting with people, whether through shared interests or key life events,» the press release states. «Now, if you’re looking for entry-level, trade and service industry employment in your community, Facebook can help you connect with local people and small businesses who are hiring.»

How to get started with Local Jobs on Facebook

According to Meta, Local Jobs will appear as a dedicated section in Facebook Marketplace starting this week. If you’re 18 or older, you can:

Tap the Marketplace tab on the Facebook app or website.
Select Jobs to browse available positions nearby.
Use filters for job type, category and distance.
Tap Apply or message the employer directly via Messenger.

Businesses and page admins can post jobs by creating a new listing in Marketplace or from their Facebook Page. Listings can include job details, pay range, and scheduling information and will appear in local searches automatically.

The Local Jobs feature is rolling out across the US now, with Meta saying it plans to expand it in the months ahead.

Technologies

Tesla Has a New Range of Affordable Electric Cars: How Much They Cost

The new, stripped-back versions of the Model Y and Model 3 have a more affordable starting price.

Technologies

Today’s NYT Strands Hints, Answers and Help for Oct. 22 #598

Here are hints and answers for the NYT Strands puzzle for Oct. 22, No. 598.

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

Today’s NYT Strands puzzle is a fun one — I definitely have at least two of these in my house. Some of the answers are a bit tough to unscramble, so if you need hints and answers, read on.

I go into depth about the rules for Strands in this story.

If you’re looking for today’s Wordle, Connections and Mini Crossword answers, you can visit CNET’s NYT puzzle hints page.

Read more: NYT Connections Turns 1: These Are the 5 Toughest Puzzles So Far

Hint for today’s Strands puzzle

Today’s Strands theme is: Catch all.

If that doesn’t help you, here’s a clue: A mess of items.

Clue words to unlock in-game hints

Your goal is to find hidden words that fit the puzzle’s theme. If you’re stuck, find any words you can. Every time you find three words of four letters or more, Strands will reveal one of the theme words. These are the words I used to get those hints but any words of four or more letters that you find will work:

BATE, LICE, SLUM, CAPE, HOLE, CARE, BARE, THEN, SLAM, SAMBA, BACK

Answers for today’s Strands puzzle

These are the answers that tie into the theme. The goal of the puzzle is to find them all, including the spangram, a theme word that reaches from one side of the puzzle to the other. When you have all of them (I originally thought there were always eight but learned that the number can vary), every letter on the board will be used. Here are the nonspangram answers:

TAPE, COIN, PENCIL, BATTERY, SHOELACE, THUMBTACK

Today’s Strands spangram

Today’s Strands spangram is JUNKDRAWER. To find it, look for the J that’s five letters down on the far-left row, and wind down, over and then up.

Quick tips for Strands

#1: To get more clue words, see if you can tweak the words you’ve already found, by adding an «S» or other variants. And if you find a word like WILL, see if other letters are close enough to help you make SILL, or BILL.

#2: Once you get one theme word, look at the puzzle to see if you can spot other related words.

#3: If you’ve been given the letters for a theme word, but can’t figure it out, guess three more clue words, and the puzzle will light up each letter in order, revealing the word.