Science Update - Ancient Supernovae and Ducks
Phil - As happens at this time every week, we're now going to go over the ocean to hear Bob and Chelsea's Science Update. This week they're going to be spotting ancient supernovae and hearing how the ancestor of modern birds may well have looked a bit like a duck.
Bob - This week for the Naked Scientists we'll discuss some spectacular bird fossils that scientists have dug up in China. But first, if you had lived in the year 1006 instead of 2006, you couldn't have missed the bright star that suddenly appeared one night in May. It was a supernova, and civilisations in Asia, Europe and the Middle East recorded it for posterity. Now Chelsea tells us that someone in North America may have noted it too.
Chelsea - The 1006 supernova was briefly the brightest object in the sky after the sun and the moon. Now astronomers have found rock art in Arizona that might be an ancient record of it. John Barentine of the Apache Point Observatory in New Mexico says the design chipped into the rock is an eight-pointed star next to a wavy line that looks like a scorpion. The 1006 supernovae would have appeared next to the constellation Scorpius.
John - There's a little bit of western bias in seeing Scorpius among the figures on this rock, but it's a pattern of stars that has a long history. It goes back 1000s of years at least in the Middle East and Eastern Mesopotamia. It turns out that in many parts of the world that are in arid climates where you would find scorpions, the figure of stars that we know called Scorpius was identified with that animal.
Chelsea - He says that we can never be sure of the artist's intentions but chemical dating could resolve whether the rock art was in fact created a millennium ago.
Bob - And now to rewind even more, it may be that all modern birds from robins to owls to ostriches evolved from duck-like ancestors. An international team of palaeontologists working in China recently discovered five new fossils of a 110 million year old ancestor of modern birds called Gansus yumenensis. Jerry Harris of Dixie State College in Utah says it probably looked and acted like today's loons and grebes.
Jerry - It has several similar features in its skeleton that show that it had a similar lifestyle of diving under water and swimming. They also had webbed feet. In some of our specimens it had skin preserved and showed that it had webbing down to the end of its toes so we know it was a water-based bird. When you put the skin and feathers back on it, you'd probably have a hard time telling the difference between it and a loon or a grebe, especially from a distance like you mostly see them in a lake today.
Bob - He says Gansus is probably not a direct ancestor of modern birds; probably more like a super-great grand uncle. He adds that it may have been a tasty dish for the dinosaurs.
Chelsea - Thanks Bob. Next week we'll learn about a love hormone that seems to soften marital spats. Until then, I'm Chelsea Wald.
Bob - And I'm Bob Hirshon for AAAS, the Science Society.