The idea of an asteroid or comet impacting with planet Earth and causing a catastrophe for mankind has long been given a cold shoulder in scientific circles. But with the notion that the dinosaurs met their fate at the hand of a rather large space rock it does not seem so outlandish anymore. NASA has started monitoring near-earth objects, but is there really something we could do if one was heading our way? Astrophysicist and science writer Andrew May provides a delightful little primer on these questions with Cosmic Impact, injecting this oft-hyped topic with a healthy dose of realism.
Our planetary neighbour Mars has long fascinated us, and the idea of there being Martian life holds a strong grip on our collective imagination. NASA and others are becoming serious about sending people to Mars. Before we do so, astronomy professor David Weintraub would like to give you this readable history of our fascination with the Red Planet and the research that tries to answer the question: is there life on Mars? (Admit it, you were crooning that David Bowie song there).
If you have used a compass, you will know our planet has a magnetic North and South pole. You might even be aware that the geographical and magnetic poles are not exactly in the same location. The magnetic poles have a tendency to wander with time. They can even swap places, and we have evidence of a long history of such geomagnetic reversals in the rock record. But how does this happen? And what would the consequences be if this happened today? Earth’s magnetic field offers protection against radiation from outer space, primarily from the sun, so if this field weakens or changes, what will happen to us and our electrical infrastructure? Join science journalist Alanna Mitchell as she explores this topic and delves into the history of electromagnetism.