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Images from the first month after DART’s asteroid collision. Each frame is the average over an entire night’s observations. The Didymos asteroid system is in the centre and stars appear as streaks.Credit: University of Canterbury Ōtehīwai Mt John Observatory/UCNZ
Spacecraft knocked 1 million kg off asteroid
The asteroid that was deliberately hit with NASA’s Double Asteroid Redirection Test (DART) spacecraft last September lost one million kilograms of rock, gained a 10,000-kilometre-long debris tail and now completes its orbit 33 minutes faster than before the collision. A detailed analysis of what happened when DART smashed into the Great-Pyramid-sized asteroid Dimorphos has revealed how successful this first test of planetary defence really was. The spacecraft hit a spot close to the asteroid’s centre and caused a large spray of rubble to fly outwards, which maximized the impact’s force and added momentum.
Reference: Nature papers 1, 2, 3, 4, 5
A racing heart spurs anxiety
Anxiety can cause the heart to race — and the reverse is also true, according to a study in mice. When researchers artificially raised the rodents’ heart rate, the animals became less willing to explore their environment, suggesting they were more anxious. Switching off the brain circuitry involved reduced the mice’s anxiety. It’s not clear whether the same body–brain loop plays a part in acute fear or chronic anxiety, but the finding could have implications for treating anxiety in humans. “You can’t just look at the brain if you want to understand fear,” says neuroscientist Sarah Garfinkel.
Read neuroscientists Yoni Couderc and Anna Beyeler’s expert analysis of the discovery in the Nature News & Views article (5 min read, Nature paywall)
How to stop bird flu becoming a pandemic
After avian influenza killed a girl in Cambodia last week, fears are rising about the virus’s potential to spark a human pandemic. It’s hard to say whether this will actually happen, says veterinary pathologist Thijs Kuiken. Versions of the H5N1 influenza virus have been circulating in birds for about 25 years, but the discovery of a variant that transmits between mink increases the risk that the virus could start spreading in humans. Scientists say it’s important to keep tracking the disease’s spread in birds and keep an eye on people who work in the poultry sector. Because drugs and vaccines against H5N1 are already available, a bird flu pandemic would probably be more manageable than COVID-19.
Ancient humans sat out ice age in Spain
European hunter-gatherers holed up in what is now Spain to escape the last ice age, which covered large parts of the continent with glaciers for several millennia. Researchers analysed DNA from 356 individuals who lived in Europe and western Asia between 35,000 and 5,000 years ago. The humans who had sought out the warmer climate on the Iberian Peninsula repopulated Western Europe after the deep freeze ended. This explains how a genetic signature that first showed up in 35,000-year-old remains popped up again in populations tens of thousands of years later — a fact that had remained a mystery until now.
Read anthropobiologist Ludovic Orlando’s expert analysis of the discovery in the Nature News & Views article (7 min read,paywall)
References: Nature paper & Nature Ecology & Evolution paper
UK scientists could soon rejoin EU funding
UK researchers are optimistic that they will regain access to the European Union’s €95.5-billion (US$101-billion) Horizon Europe funding scheme, after a Brexit agreement on the status of Northern Ireland was reached earlier this week. The United Kingdom will rejoin as an ‘associate’ country, which gives scientists the same level of financial access as before Brexit but no say in what research fields will be prioritized in the programme’s next iteration. A couple of political hurdles remain, but the most difficult might be rebuilding the collaboration networks that have atrophied over the past few years, says science-policy researcher James Wilsdon.
Features & opinion
Why it’s so hard to copy the IPCC
When it comes to getting decision makers to pay attention to science, there are few better examples than the Intergovernmental Panel on Climate Change (IPCC). Yet there are no similar advisory bodies for other global challenges such as inequality or food security, and not for want of trying. The way the IPCC came to be — with many government climate scientists among its founders — cannot easily be replicated, explains a Nature editorial. “The world might never again see a research assessment on the scale that the IPCC pioneered, but that is far from the only way for policymakers to access — and act on — scientific evidence.”
Did climate change cause mass cow deaths?
Last year, millions of cows across India became infected with a highly contagious virus that causes lumpy skin disease — the first outbreak of the disease in the country. Researchers say that climate change could have been a factor in the emergence of the virus, which spreads through flies. More than 150,000 cows died across India, half of them in the northern state of Rajasthan. The state’s milk production crashed by 21%, at the same time as resident farmers were struggling with failing crops. Warm, humid climates support the disease-carrying insects’ reproduction, and Rajasthan has seen a gradual increase in heavy rainfall days and average temperatures over the past few decades. “It’s difficult to attribute the cause of lumpy’s spread to solely climate, but climate definitely played a role,” says veterinary epidemiologist Rathish R.
How to check your curriculum’s diversity
“Simply expanding reading resources is not enough,” write psychologists Sakshi Ghai, Lee de-Wit and Yan Mak after they revealed a striking lack of voices from under-represented groups and regions in their university’s undergraduate psychology reading material. The team has four recommendations for others wanting to do similar audits: tailor the definition of diversity to your field, start by dissecting the curriculum’s foundational courses, gather diversity data while remaining aware of its limits, and place people from minority ethnic groups at the heart of the audit.
