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An image of Perseverance taken by a rocket-powered ‘sky crane’ as it lowered the rover onto Mars’s dusty surface on 18 February.Credits: NASA/JPL-Caltech
Spectacular video of rover’s Mars landing
Humanity just got a front-row seat to a Mars landing, thanks to a high-resolution, full-colour video of the Perseverance rover descending into Jezero Crater on 18 February. Watch the drama of the spacecraft’s jaw-dropping final descent, from the 21.5-metre-wide parachute billowing overhead to the final moments when the rover’s six corrugated wheels touched down on the red, rock-studded surface. “These videos are the stuff of our dreams,” says mission engineer Al Chen.
Done right, contact-tracing apps work
The evidence is mounting that contact-tracing apps for smartphones can help to prevent COVID infections and are a valuable public-health tool. Researchers in the United Kingdom estimate that every 1% increase in users of the British COVID-19 app — as long as it has a user base of at least 15% of the population — reduces the number of infections by 0.8–2.3%. And the apps seem to shorten the time taken to identify people who need to quarantine, particularly for contacts who don’t live together. But to succeed, these apps need adequate political backing and to be properly integrated into public-health systems.
Life-size kangaroo is Australia’s oldest art
A kangaroo painted in red ochre in a rock shelter in remote northwestern Australia is at least 17,100 years old — the oldest rock art yet dated on the continent. It’s difficult to determine the age of Australian rock art because the region’s ancient artists didn’t tend to use organic materials that can be radiocarbon dated. In this case, researchers analysed fossilized mud-wasp nests laying over and under the art. Alongside the kangaroo, the richly decorated cave includes images interpreted as a boomerang, a reclining human figure and a 3-metre-long snake.
Go deeper with the News & Views article by anthropologist and archaeologist Paul Taçon (Nature Human Behaviour | 5 min read)
Reference: Nature Human Behaviour paper
Organoids mimic postnatal brains
Clusters of stem cells grown in the laboratory, if cultured long enough, will turn into brain-like structures with similarities to newborn brains. Previously, researchers assumed such structures, called brain organoids, could only mimic fetal brain development. But the new research demonstrated that after 250 to 300 days in culture — around the same amount of time a fetus needs to prepare for birth — the organoids started expressing the same genes that brains of newborn babies do. They lack a real brain’s electrical activity, blood vessels, immune cells and sensory inputs, but other features, such as their methylation patterns, show striking similarity. The researchers suggest the organoids can be used to study brain disorders, such as schizophrenia. “Things that, before I saw this paper, I would have said you can’t do with organoids … actually, maybe you can,” says developmental geneticist Madeline Lancaster.
Reference: Nature Neuroscience paper
Features & opinion
Closing in on a complete human genome
Advances in sequencing technology mean that scientists are on the verge of finally finishing an end-to-end human genome map, 20 years after the first draft of the human genome was published. “This wasn’t just doing it for the sake of doing it,” says genomics researcher Karen Miga of the Telomere to Telomere (T2T) consortium, which is poised to complete the odyssey that began with the release of that first draft sequence. “It was because I think there’s some really cool biology there.”
How we won March Mammal Madness
The science-outreach tournament March Mammal Madness involves a tongue-in-cheek bracket of animal ‘battles’ that takes place on social media. The event’s organizers share a detailed account of how they combine humour and scientific rigour to inspire engagement with animal behavior and the natural world.
