Technologies

Huge ancient lake on Mars could be hiding fossilized signs of alien life

An ancient river delta at the site where NASA’s Perseverance rover landed might hold proof of past life on Mars.

Mars rovers may soon get a few new checkpoints to explore. Geologists say specific areas of an ancient river delta near where NASA’s Perseverance rover is stationed could hold fossilized evidence of extraterrestrial life.

Though they don’t expect to find any bug-eyed, green aliens, they do say vital organic compounds that suggest the presence of past life might exist there, waiting to be uncovered.

The crew of researchers behind the new study, published on Oct. 7 in the journal Science, dissected photographs taken by NASA’s recently landed Perseverance rover and uncovered ways that water flowed on Mars billions of years ago.

Their analysis unveiled spots on the arid orb that could house the highly sought-after biosignatures.

«We know that water was running on the surface at one point in the past, but we don’t know the duration of this activity,» said the study’s lead author, Nicolas Mangold, a geologist at the University of Nantes in France.

NASA’s Perseverance and the legend of Jezero

Once upon a time in space, Mars wasn’t a dry and dangerous world. It was covered in fresh rivers and lakes, a lot like those on Earth. And where there’s water, there could be life.

The vast bodies of H2O dried up eons ago as the formerly blue planet’s delicate atmosphere disappeared. This turned the environment into the inhospitable land we’ve come to know today.

Scientists have long been intrigued by the past existence of water on Mars. That’s why NASA sent Perseverance to traverse the planet in hopes of finding fingerprints of life. More specifically, they sent the rover to a huge crater called Jezero.

Believed to have once been flooded by water, the Jezero crater houses an ancient river delta — a delta that could be holding signs of alien life.

Deltas are landforms generated by rock and sediment swept up by a river’s flow. That stream often carries organic molecules and bacteria in its path, which means Jezero’s delta could easily contain an accumulation of such materials.

In other words, it could contain fossilized building blocks of life.

With that in mind, the study team’s proposed points of interest for locating evidence of life on Mars are all anchored by that delta. Initially, Mangold says, he hoped Perseverance would catch clear images of the spot, but unfortunately, Percy is a bit too far from the old river for that.

«Despite our disappointment,» he said, «we tried to look at the delta from a distance using our best cameras, and that gave really wonderful results.»

Clues from Kodiak

Surprisingly, the researchers didn’t find the prized areas just by analyzing Jezero’s main delta. They observed a nearby butte, or mound of rock, dubbed Kodiak. Kodiak is a part of the delta that’s slightly farther away.

«You can imagine that the delta was a little bit extended to the south and to the east, then erosion removed some of the material,» said Mangold. «But Kodiak is, by miracle, preserved.»

Kodiak serves as a geologic representation of the main river delta’s features. The stratigraphy, its rock layers, is relatively easy to see from afar, according to the researchers.

«By understanding the stratigraphy at Kodiak, it enables us to identify the deposits which are the most likely of interest for life preservation,» Mangold said.

He described the team’s first look at the photos as a «shock.»

«The first image is actually [one] where we can see boulders,» he said. «A delta fault … is not supposed to get some big boulders. It’s supposed to be consistent.»

Those boulders, he said, mean Jezero’s river delta is what’s called a Gilbert-type delta. These are formed with stronger water flow such as waves and tides, like that found in a lake. Thus, the team believes the river’s flow suddenly grew more intense during the course of its life.

«A big question for us,» Mangold said, «is to understand why there was this change of hydrological activity, because that is probably the signature of a change of climate.»

Kodiak also offered insight into how high the ancient body of water rose. Mangold says it would’ve been about 8,202 feet (2,500 meters) high, based on striations of rocks in the butte. That elevation varied over time, he says, which is also consistent with the idea the river advanced into a lake.

«That kind of observation is really key,» he explained. «Because it shows that there was a lake in Jezero, no doubt about that … in addition, the change from horizontal bedding to the faults, which are deep in layers, indicates the past water level.»

In the end, all this knowledge led Mangold’s team to isolate places where remnants of life could be found — deeper layers of Kodiak that likely have mud-dominated residue as well as sand grains. These types of sediments have been known to contain organic, life-sustaining molecules.

«Kodiak is not easily accessible by the rover because it’s a bit vertical facing,» Mangold noted.

«But we have identified some locations on the main delta fault where we can access similar types of layers. Those locations are some of our preferred targets for future rover travels.»

Technologies

Bishop Takes Rook: You’ll Be Able to Learn Chess on Duolingo Soon

The course is in beta now but will be available to everyone in a few months.

«Hola, ajedrez» means «Hello, chess» in Spanish. You’ve always been able to learn Spanish on Duolingo. And you’ll be able to learn and practice chess on the language learning app soon. Duolingo announced on April 22 that beta testers can practice the centuries-old board game in Duolingo now, and others will be able to learn the game on the app in a few months.

Chess will be the first new Duolingo course since the app began offering math and music lessons in 2023. And Duolingo hopes that to bring the classic board game to more people of all experience levels.

Duolingo chess lessons aim to be friendly to beginners

I spoke with a Duolingo rep about the upcoming lessons. He said the company wants to continue expanding what people can learn through the app, and chess was an early contender.

Chess is «one of those things that … any age group can learn … but then also something that takes the 10,000-hour theory to really master,» Edwin Bodge, a senior product manager with Duolingo, said. «We thought it would fit with the Duolingo medium really well.»

When I asked why people would use Duolingo over other chess learning sites and tools, Bodge said a lot of other chess content is geared toward advanced users, not newcomers. «We really saw a great opportunity to try and cater to more of a beginner, medium (player) and try and increase access to the game,» he said.

The chess lessons are slightly different from others you might find on Duolingo, like Spanish and math, but the progression system is similar. And from what Duolingo showed me, the lessons really do start at square one, or A1 on a chessboard.

Chess lessons feel similar to other Duolingo lessons

When you start, Duolingo asks how much you already know about chess, like in other lessons on the app. Duolingo will then adjust the lessons according to your response. If you say you’re brand-new to chess and have no knowledge of the game, early lessons will focus on how each piece moves before moving on to capturing other pieces and checking the king. Other lessons are similar to mini-puzzles where you might be asked to capture different pieces using a single piece, like your knight or rook, in four moves or fewer.

You can access hints for each lesson, but if you get something wrong, your opponent will react to show you you’ve left a piece open for capture, like in a real match. And if you keep getting something incorrect, Duolingo will show you what to do. «If you get it wrong multiple times, eventually we’ll show you an arrow that shows you exactly where to move,» Sammi Siegel, a software engineer with Duolingo, said.

If you are subscribed to Duolingo Max and make a mistake in a language lesson, the app can explain the mistake — and what the right solution is — with a feature called Explain My Answer. However, that feature won’t be available with the chess lessons for now. It’s not always easy to explain why something is right or wrong in chess because there are so many millions of different moves.

«We want to get better at fuller explanations,» Siegel said. «There is some mix of AI and model training that we’re hoping to use to better explain why a certain move is wrong.» Because there are so many moves in chess, it’s possible to make moves that could be correct but aren’t the best options. In such instances, Duolingo will show a banner that lets you know that a move isn’t wrong but isn’t necessarily the best move.

Duolingo also said each section represents a range on the Elo rating system, the method by which a chess player’s skills are calculated. As you progress, your lessons will be tougher and more challenging. This is similar to the CEFR language proficiency levels attached to the different language sections in the app.

You’ll also have the opportunity to have «mini-matches» or full-on games against Duolingo’s chess coach, Oscar. These matches will scale in difficulty to challenge you as well, so you aren’t facing a grandmaster-level chess player after your first week of playing the game. But that doesn’t mean you can slack off and play sloppily. If you make a mistake, like leaving your queen open to capture, Oscar will take advantage and leave you scrambling to recover.

While playing against Oscar is good practice, you won’t be able to face off against other players when these chess lessons launch. But Duolingo said matches against other people are something they are looking into, so you might be able to play against a friend over the app in the future. «One of the big reasons why we’re doing this is we think we can get a whole generation of people interested in chess,» Bodge said.

Duolingo’s new chess lessons are now available in the beta version now and will start rolling out on iOS in English in May. Duolingo said it is working to bring these lessons to Android devices and more languages in the coming months.

For more on Duolingo, check out how well the free version prepared me for a trip to Italy and our review of the language learning app. You can also check out our best language learning apps.

Technologies

Today’s NYT Mini Crossword Answers for Sunday, April 27

Here are the answers for The New York Times Mini Crossword for April 27.

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.

Today’s NYT Mini Crossword isn’t too much of a stumper. A lot of words contain A and E, for some reason. Need some help with today’s Mini Crossword? Read on. And if you could use some hints and guidance for daily solving, check out our Mini Crossword tips.

The Mini Crossword is just one of many games in the Times’ games collection. 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 at those Mini Crossword clues and answers.

Mini across clues and answers

1A clue: Outdoor spot to people-watch, maybe
Answer: STOOP

6A clue: Big name in health insurance
Answer: AETNA

7A clue: Broadway theater helper
Answer: USHER

8A clue: Easy to understand
Answer: CLEAR

9A clue: When many show up to a job interview
Answer: EARLY

Mini down clues and answers

1D clue: What «salsa» literally means
Answer: SAUCE

2D clue: Electric car maker since 2003
Answer: TESLA

3D clue: «… in one ear and out the ___»
Answer: OTHER

4D clue: Tatum ___, youngest-ever Oscar winner (at age 10, for Best Supporting Actress)
Answer: ONEAL

5D clue: Defensive maneuver in fencing
Answer: PARRY

How to play more Mini Crosswords

The New York Times Games section offers a large number of online games, but only some of them are free for all to play. You can play the current day’s Mini Crossword for free, but you’ll need a subscription to the Times Games section to play older puzzles from the archives.

Technologies

Today’s NYT Connections: Sports Edition Hints and Answers for April 27, #216

Hints and answers for the NYT Connections: Sports Edition puzzle, No. 216, for April 27.

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.

Connections: Sports Edition might be a breeze, as long as you know your sports-league commissioners. Read on for hints and the answers.

Connections: Sports Edition is out of beta now, making its debut on Super Bowl Sunday, Feb. 9. That’s a sign that the game has earned enough loyal players that The Athletic, the subscription-based sports journalism site owned by the Times, will continue to publish it. It doesn’t show up in the NYT Games app but now appears in The Athletic’s own app. Or you can continue to play it 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: Dunk it.

Green group hint: Get it moving.

Blue group hint: They run the leagues.

Purple group hint: Like house, kind of.