The climate is changing. So are we. On What On Earth, you’ll explore a world of solutions with host Laura Lynch and our team of journalists. In 1970, 20 million people showed up to fight for the environment on the first Earth Day. More than five decades later, is it time for this much tamer global event to return to its radical roots?  OG organizer Denis Hayes recounts how – amidst other counterculture movements at the time – his team persuaded roughly one in ten Americans to take to the streets. As he approaches 80, Denis offers his singular piece of advice to the next generation of cli ..read more

Old canned salmon provides a record of parasite infection To study marine ecosystems from the past, scientists picked through canned salmon dating back more than four decades to measure levels of parasites in the fish. Natalie Mastick, a postdoctoral researcher in marine ecology at Yale University, said she found the parasite load in two species of salmon increased in their samples between 1979 - 2021. She says this suggests their ecosystems provided more of the hosts the parasites needed, including marine mammals, which could reflect an increasingly healthy ecosystem. Their study is in the jo ..read more

Seeing a black hole’s magnetic personality Scientists using the Event Horizon Telescope have produced a new image of the supermassive black hole at the centre of our galaxy. And this image is a little different: it captures the powerful magnetic fields that are acting as the cosmic cutlery feeding mass into the singularity. Avery Broderick is part of the Event Horizon Telescope team, he’s also a professor at the University of Waterloo’s Department of Physics and Astronomy, and associate faculty at the Perimeter Institute for theoretical physics. Decoding how chickadees maintain a mental map o ..read more

Archaeologists identify a medieval war-horse graveyard near Buckingham Palace  We know knights in shining armor rode powerful horses, but remains of those horses are rare. Now, researchers studying equine remains from a site near Buckingham Palace have built a case, based on evidence from their bones, that these animals were likely used in jousting tournaments and battle. Archeologist Katherine Kanne says the bone analysis also revealed a complex, continent-crossing medieval horse trading network that supplied the British elites with sturdy stallions. This paper was published in Science A ..read more

How animals dealt with the ‘Anthropause’ during COVID lockdowns (1:04) During the COVID lockdowns human behaviour changed dramatically, and wildlife scientists were interested in how that in turn changed the behaviour of animals in urban, rural and wilderness ecosystems. In a massive study of camera trap images, a team from the University of British Columbia has built a somewhat surprising picture of how animals responded to a human lockdown. Cole Burton, Canada Research Chair in Terrestrial Mammal Conservation at the University of British Columbia, was part of the team and their research was ..read more

Why a detective is studying blood spatters in zero-gravity There hasn’t been a murder on the International Space Station — yet. But Crime Scene Investigator Zack Kowalske has been studying how blood spatters in microgravity so that when someone does commit the first astro-cide, he’ll be able to use science to figure out whodunit. Kowalske sent a blood substitute for a ride on a parabolic microgravity flight to study how the absence of gravity changes how it moves, and discovered that surface tension takes over to shape how the blood splatters. The research was published in the journal Forensi ..read more

Nature’s nurturing side — disabled primates thrive in the wild with community support Survival of the fittest for primates in the wild often includes them going out of their way to accommodate those with physical disabilities. In a study in the American Journal of Primatology, scientists reviewed 114 studies of a wide range of non-human primates that spanned more than nine decades. Brogan Stewart, a PhD candidate from Concordia was part of the team that found that more often than not, the physical disabilities arose as a result of human activities, and in the face of those pressures, primates ..read more

We now know what happened to a supernova discovered by a Canadian 37 years ago (0:58) A mystery about the ultimate fate of an exploding star has been solved. Canadian astronomer Ian Shelton discovered the new bright light in the sky back in February 1987, and recognized it as the first supernova to be visible to the naked eye in 400 years. In a new study in the journal Science, astrophysicist Claes Fransson from Stockholm University, confirmed that the remaining cinder collapsed into a super-dense neutron star. A vibrating pill makes pigs feel full (10:30) There’s a lot of interest in weight ..read more

Atlantic ocean circulation edging closer to potentially catastrophic climate tipping point The stability of much of the world’s climate depends on ocean currents in the Atlantic that bring warm water from the tropics north and send cool water south. New research in the journal Science Advances confirms what scientists have long feared: that we are on course to this tipping point that could cut off this important circulation pattern, with severe consequences. René van Westen from Utrecht University, said if we reach this critical threshold, it could plunge Europe into a deep freeze, disrupt rai ..read more

Blue whales are genetically healthy but are breeding with fin whales, study suggests (1:03) Researchers have sequenced the genome of a blue whale that washed up in Newfoundland in 2014, and used it to do a comparative study of North Atlantic blue whales. A team led by Mark Engstrom, curator emeritus at the Royal Ontario Museum found that despite their small population, the whales are genetically diverse and connected across the north Atlantic, but that on average blue whales from this group are, genetically, about 3.5 per cent fin whale. The work was published in the journal Conservation Genet ..read more