This week’s science news was largely dominated by the return of two NASA astronauts from the International Space Station, whose planned eight-day mission ended up lasting 286 days.
Astronauts Butch Wilmore and Suni Williams lifted off from Florida’s Cape Canaveral Space Force Station on June 5, 2024, but not long into the mission helium leaks, along with a number of other issues, were discovered on their Boeing Starliner spacecraft.
Starliner had already suffered years of delays, and although it was later suggested the pair would have been fine to return home on the suspect vessel, the risk to their safety was considered too great. As such, it wasn’t until 5:57 p.m. ET on Tuesday (March 18) that the astronauts finally splashed down near the coast of Florida, after hitching a lift aboard a SpaceX Dragon capsule.
While much of the attention on them focused on the duo being “stranded” in space, it’s not a sentiment the pair shared. In a conversation with CNN’s Anderson Cooper, they explained how mission extensions are sometimes just part of the job.
“We come prepared, we come committed. That is what your human spaceflight program is: It prepares for any and all contingencies that we can conceive of, and we prepare for those,” Wilmore told Cooper. “We don’t feel abandoned. We don’t feel stuck. We don’t feel stranded.”
Related: NASA astronauts Suni Williams and Butch Wilmore were carried away on stretchers after return from space. Here’s why that’s normal.
Mystery ancestors
In a study published Tuesday, researchers presented a new method of modeling genomic data, called “cobraa,” that has enabled them to trace the evolution of modern humans (Homo sapiens).
They found that the ancestors of all modern humans split off from a mystery population 1.5 million years ago and then reconnected with them 300,000 years ago. This unknown population contributed 20% of our DNA and may have boosted humans’ brain function.
“The fact that we can reconstruct events from hundreds of thousands or millions of years ago just by looking at DNA today is astonishing, and it tells us that our history is far richer and more complex than we imagined,” study co-author Aylwyn Scally, a geneticist at the University of Cambridge, said in a statement.
Discover more archaeology news
—Mechanical Dog: A ‘good boy’ from ancient Egypt that has a red tongue and ‘barks’
—European hunter-gatherers boated to North Africa during Stone Age, ancient DNA suggests
—‘Not enough survives to read the king’s name’: Tomb discovered of unknown ancient Egyptian pharaoh
Life’s Little Mysteries
Just like the mountains, lakes on Earth can be ancient, or more than 1 million years old. There are only 20 ancient lakes on the planet, but which is the oldest?
Largest-ever space map
Astronomers studying the largest-ever map of the cosmos have found hints that our best understanding of the universe is due a major rewrite. The analysis, which looked at nearly 15 million galaxies and quasars spanning 11 billion years of cosmic time, found that dark energy — the presumed-to-be constant force driving the accelerating expansion of our universe — could be weakening.
Or at least this is what the data, collected by the Dark Energy Spectroscopic Instrument (DESI), suggest when combined with information taken from star explosions, the cosmic microwave background and weak gravitational lensing. If the findings hold up, it means that one of the most mysterious forces controlling the fate of our universe is even weirder than first thought — and that something is very wrong with our current model of the cosmos.
Discover more astronomy news
—James Webb telescope spots ‘rogue’ planet with a cake-like atmosphere barrelling through space without a star
—Scientists find evidence of ‘supernova graveyard’ at the bottom of the sea — and possibly on the surface of the moon
—‘I was astonished’: Ancient galaxy discovered by James Webb telescope contains the oldest oxygen scientists have ever seen
Also in science news this week
Also in science news this week
—Google’s AI ‘co-scientist’ cracked 10-year superbug problem in just 2 days
—AI analysis of 100 hours of real conversations — and the brain activity underpinning them — reveals how humans understand language
—Scientists create new map showing ice-free Antarctica in more detail than ever before
—Iguanas sailed one-fifth of the way around the world on rafts 34 million years ago
—Punishing AI doesn’t stop it from lying and cheating — it just makes it hide better, study shows
Science spotlight
Around four years ago, now 77-year-old John Gormly went for what was supposed to be a routine blood test. But the results were life-changing.
The test suggested Gormly had colon cancer, which a colonoscopy later confirmed was Stage 2, meaning the cancer had spread through the wall of the colon but not to his lymph nodes.
“I thought [my doctor] was wrong,” Gormly, CEO of a construction company near Newport Beach, California, told Live Science. “I go, ‘Nah, I don’t feel anything.’ But there it was. It was real; the colonoscopy showed it.”
Gormly was one of the first patients to take a newly approved test called Shield, which its makers say can detect colon cancer from a blood sample. After his diagnosis, Gormly had surgery to remove the tumor and was back at work within 10 days.
“Liquid biopsies” like the one that detected early cancer for Gormly are now coming to market. Could they lead to earlier diagnosis and treatment?
Something for the weekend
Something for the weekend
If you’re looking for something a little longer to read over the weekend, here are some of the best long reads, book excerpts and interviews published this week.
—March 29 solar eclipse: Where and when to see the rare sunrise solar eclipse from North America (Skywatching)
—Dolphins: Facts about the intelligent marine mammals that use tools to hunt (Fact file)
—‘Heat is the final boss. Heat is a different beast’: The planetary peril no one will be able to avoid (Book extract)
—‘We have to fight for a better end’: Author John Green on how threats to USAID derail the worldwide effort to end tuberculosis (Interview)
Science in motion

Watch On
An octopus has been spotted catching a ride from an unlikely marine friend: a superfast shark. Researchers captured a video showing the orange-hued octopus clinging to the back of a large shortfin mako shark (Isurus oxyrinchus) as it swims. This “sharktopus” was spotted in the Hauraki Gulf off the northern coast of New Zealand’s North Island during a December 2023 research trip.
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