Southern Hemisphere

Dr Neil deGrasse Tyson's has attracted one of the world's largest online followings with his fascinating, widely accessible insights into science and our universe. He joined Jim Mora to discuss his… Audio

Blistering cold weather in America has made some parts of the country almost 20 degrees colder than Antarctica. As Bridget Burke reports, it's so cold that people are being told not to breathe too… Video, Audio