A record summer temperature in Siberia is an indication of major changes in the Arctic climate. Changing weather patterns there have a knock on effect for other parts of the planet says Climatologist Steve Vavrus

Chile appeared to get Covid-19 under control, but in reality the virus was spreading uncontrollably through poor areas, As we hear from our correspondent in Santiago Jane Chambers, the lockdown has tightened but cases continue to rise.

And could mass testing using new saliva tests help control or even end the epidemic? Epidemiologist Julian Peto tells us about his plan which is designed to contain the virus within individual households and stop community spread.

Experiments to investigate dark matter have produced some tantalising results, Physicist Laura Manenti says it’s not confirmation of detection, but potentially close.

If you put one person’s blood into another person , sometimes it’s fine and sometimes it’s a death sentence.

French physician Jean-Baptiste Denis discovered this when he performed the first blood transfusion back in 1667. He put the blood of a lamb into a 15-year boy. The teenager survived but Denis’s third attempt killed the patient and led to a murder charge.

In 1900, Austrian doctor Karl Landsteiner discovered the reason for this lottery – blood types. The red blood cells in our bodies are decorated with different marker molecules called antigens. These define us as A, B, AB or O blood type. And this is just one of 38 different systems for classifying our blood. CrowdScience listeners have discovered that we aren’t the only animal with blood types and want to know more.

Dogs have 12 different blood groups, so how do they cope when they need a transfusion? CrowdScience meets some very good dogs who donate a pint to the pet blood bank in return for a toy and a treat. Each pint saving up to 4 other dogs’ lives.

We also hear how examining our blood types can tell us more about our links to our ape-like cousins and how the human species spread around the world. And what about the future of blood types – can we use science, and animal blood to get around the problems of transfusions?

(Image: Rural Scene in Verkhoyansk. Credit: Dean Conger/Corbis via Getty Images)