In Puna de Atacama, a high plateau in northwestern Argentina, researchers uncovered a system of lagoons that contain living giant stromatolites, or layered rocks created by microbes.
In Puna de Atacama, a high plateau in northwestern Argentina, researchers uncovered a system of lagoons that contain living giant stromatolites, or layered rocks created by microbes.
Brian Hynek

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It’s impossible to know what Mars looked like billions of years ago, but one robotic explorer’s intrepid sleuthing is giving astronomers a peek into the past.

The NASA Perseverance rover just marked 1,000 days on the red planet. Percy has completed its investigation of an ancient river delta that fed into?a Martian surface feature called?Jezero Crater.

By studying and sampling rocks?since landing in February 2021, the rover has helped scientists piece together a timeline of?when a shallow lake filled the crater.

Now, the rover continues its quest to find signs of past life on the red planet. And a new discovery on Earth could provide scientists with an idea of what fossils may look like if they exist on Mars.

Once upon a planet

The giant stromatolites of Puna de Atacama represent the earliest fossil evidence for life on our planet, according to new research.
The giant stromatolites of Puna de Atacama represent the earliest fossil evidence for life on our planet, according to new research.
Brian Hynek

A previously hidden system of lagoons in Puna de Atacama, an arid plateau in northwestern Argentina, is providing a rare window into what ecosystems were like on early Earth billions of years ago.

Within the lagoons are living fossils called giant stromatolites, or layered rocks created by algae and minerals such as gypsum and rock salt.

The inhospitable environment of the high salt plains is often compared with Mars. But since the red planet was likely covered with lakes and perhaps an ocean billions of years ago, Mars may have once been more similar to Earth.

“If we’re going to find any sort of fossils on Mars, this is our best guess as to what they would be, because these are the oldest ones from the Earth rock record,” said Brian Hynek, a professor in the department of geological sciences at the University of Colorado Boulder.

Other worlds

Saturn’s moon Enceladus has long intrigued astronomers as an ocean world in our solar system that may support life.

Plumes of ice grains and water vapor rise from cracks in its thick, icy crust, hinting at the presence of a salty subsurface ocean. And now, a new analysis of data collected by NASA’s Cassini mission has revealed hydrogen cyanide, a molecule that plays a key role in the processes driving the origin of life.

What’s more, the research team found evidence that the moon has a chemical energy source driven by organic compounds.

Together, the presence of water, energy and the building blocks of life suggest that Enceladus might be the?best place to search for life beyond Earth.

Discoveries

This Bavarian sword was found in all its shimmering splendor, despite spending thousands of years in the dirt.
This Bavarian sword was found in all its shimmering splendor, despite spending thousands of years in the dirt.
Bayerisches Landesamt für Denkmalpflege

Some of the most exciting art and archaeological?finds of the year were both unconventional and unexpected.

History sleuths identified the man carrying a bundle of sticks on the cover of Led Zeppelin’s 1971 album commonly known as “Led Zeppelin IV.”

Researchers discovered the oldest known European shoes and unearthed a still glimmering Bronze Age sword.

And nearly 400-year-old murals emerged from behind a kitchen wall, while a?hidden hallway was found inside the Great Pyramid of Giza.

We are family

People who tend to rise early may owe some of the credit to Neanderthals, according to new research.

Neanderthals evolved while living at high latitudes in Europe and Asia for hundreds of thousands of years. Over time, our extinct relatives likely became better adapted to seasonal variations in daylight compared with early modern humans who lived closer to the equator in Africa.

This genetic legacy may have been passed on as humans migrated across the globe and encountered Neanderthals. It’s just?one of many Neanderthal genes that have been traced?from ancient DNA and discovered in modern human populations.

Across the universe

A new high-definition image from the NASA/ESA/CSA James Webb Space Telescope's NIRCam (Near-Infrared Camera) unveils intricate details of supernova remnant Cassiopeia A (Cas A), and shows the expanding shell of material slamming into the gas shed by the star before it exploded. The most noticeable colours in Webb's newest image are clumps of bright orange and light pink that make up the inner shell of the supernova remnant. These tiny knots of gas, composed of sulphur, oxygen, argon, and neon from the star itself, are only detectable thanks to NIRCam's exquisite resolution, and give researchers a hint at how the dying star shattered like glass when it exploded. The outskirts of the main inner shell look like smoke from a campfire. This marks where ejected material from the exploded star is ramming into surrounding circumstellar material. Researchers have concluded that this white colour is light from synchrotron radiation, which is generated by charged particles travelling at extremely high speeds and spiralling around magnetic field lines. There are also several light echoes visible in this image, most notably in the bottom right corner. This is where light from the star's long-ago explosion has reached, and is warming, distant dust, which glows as it cools down. [Image description: A roughly circular cloud of gas and dust with complex structure. The inner shell is made of bright pink and orange filaments studded with clumps and knots that look like tiny pieces of shattered glass. Around the exterior of the inner shell, there are curtains of wispy gas that look like campfire smoke. Around and within the nebula, various stars are seen as points of blue and white light. Outside the nebula, there are also clumps of dust, coloured yellow in the image.]
New details shine in the James Webb Space Telescope's image of the supernova remnant Cassiopeia A.
NASA/ESA/CSA/STScI

A new image taken by the James Webb Space Telescope has allowed astronomers their closest and most detailed look inside the remains of an exploded star.

It’s the second time researchers have used Webb to observe Cassiopeia A, a glowing supernova remnant in our galaxy.

Some of the newly spotted features include?ghostly light echoes, which look like the offspring of the massive cosmic cloud.

Separately, a team of researchers observed a mysterious, repeating fast radio burst from space that has a never-before-seen quirk: The phenomenon has a?frequency that sounds like a celestial slide whistle.

Curiosities

Settle in and embark on a journey with these unusual reads:

— Engineers are trying to solve a computer glitch on the 46-year-old Voyager 1 spacecraft, which has stopped sending back scientific data as it explores the?outer edges of our solar system 15 billion miles away.

— The massive, well-preserved?skull of a prehistoric sea monster was found?on a beach in southern England and will be detailed in a documentary presented by legendary naturalist Sir David Attenborough.

— Scientists have discovered an?unusual phenomenon that keeps Himalayan glaciers cool?despite warming global temperatures.

Like what you’ve read? Oh, but there’s more.?Sign up here?to receive in your inbox the next edition of Wonder Theory, brought to you by CNN Space and Science writers?Ashley Strickland?and?Katie Hunt. They find wonder in planets beyond our solar system and discoveries from the ancient world.