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Scientists say the record-breaking Pacific North-West heatwave of recent weeks must have been caused by human induced climate change, but as Geert Jan van Oldenborgh explains to Roland Pease, despite a herculean effort to analyse the event in just a week, the precise mechanism to cause such an extreme and sudden event is so far bewildering climate modellers, exceeding even worst expectations.

Looking to the skies, Rosita Kokotanekova of the European Southern Observatory and colleagues have been getting excited about the discovery of a comet maybe twice as large as any observed before. Being so big, it has been spotted much further out from the sun and – if the best telescopes can be convinced to join the fun – will provide astronomers a chance to observe the core of the comet before the solar heat induces a gaseous coma to form as it nears the point in its orbit closest to the sun. It will be around for the next decade before continuing its several million year journey around our mutual star.

But it won’t get terribly close to earth, at least not as close as lumps of an asteroid that fell onto a driveway in the UK earlier this year. Dr Ashley King of the UK’s Natural History Museum is leading a consortium of scientists (benefitting from a rapid research grant by the UK’s STFC) who have now officially classified it and named it. The Winchcombe meteorite is a CM carbonaceous chondrite, meaning it represents the unspoilt early building blocks of the solar system. Falling like 4.5 billion year old leftover celestial lego, only a few are known around the world but perhaps none have been in scientists hands in such a short period of time, continuing its pristine survival.

Dr Pablo Tsukayama has published a preprint paper announcing a new variant of interest in the ongoing evolution of the SARS-CoV2 virus. Now named by the WHO as the Lambda variant, it seems it has driven the pandemic for much of this year in Peru – as much as 80% of cases – and large fractions of the outbreak elsewhere in South America. But as Pablo suggests, the reason we don’t know as much about it as for example the Alpha or Delta variants is likely because it hasn’t thus far affected the countries best equipped to do the analysis. Maybe that could change.

Standing takes less energy than walking, so why does it feel more tiring? At least, it does for CrowdScience listener Nina. She can march for hours without getting tired, but her legs and feet get achy after just a short time standing still.

It’s one of three walking-themed questions CrowdScience is tackling this week. Taking inspiration from our active listeners, Marnie Chesterton walks up a hill with Caroline Williams, author of a new book about why humans are designed to move. We find out how our whole system – body and brain – works better when we’re walking, compared to standing still. We’re probably set up this way because of our evolutionary history: hunting and gathering needed us to be ‘cognitively engaged endurance athletes’.

We stop for a break.. but is it true that we shouldn’t sit down to rest during a walk? Our listener Sarah is a keen hillwalker but likes to take the weight off her feet every now and again. Her hillwalking friends disapprove, saying she should rest on her feet. Is this a myth CrowdScience can bust?

And finally a question from listener Matteo: is walking or running better for your health? Numerous studies show significant benefits to both forms of exercise, but in the end, the best kind of exercise is the one you’re motivated to do.

Image: Wildfires in Lytton, British Columbia
Credit: ProPics Canada Media Ltd/Getty Images

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