It’s International Asteroid Day. The June 30th date was chosen to mark the anniversary of the Tunguska air blast over Siberia in 1908. This event occurred when an incoming meteor exploded in spectacular fashion as it met the Earth’s atmosphere. The resultant blast was so large that it would have registered 5.0 on the Richter scale! The UN decided to designate this day in the hope that we (as humans) would start to appreciate the threat that asteroids may play in our future. It is a certainty that an asteroid (or comet) is heading our way and unless we study them now – to work out what they’re made of and how they behave on their orbits around the Sun – we won’t know how to prevent one hitting us. It’s not just science fiction and Hollywood that has to deal with such scenarios (reference Armageddon and Deep Impact). Planetary Defence is becoming an increasingly important field of scientific research with aims to either divert or destroy space objects that might be heading our way in the future. OK, so we probably won’t need the likes of Bruce Willis and Ben Affleck playing ‘would-be’ space miners, but the chances are that we’ll send robotic spacecraft to do their job.
But I just want to point out how awesome asteroids are. They are some of the oldest objects in the Solar System and they hold many secrets about the formation of the planets. They even have the potential to tell us how Earth became the life-giving planet that it is today. The funny thing is that they are all different, taking on a multitude of shapes, sizes and compositions. We can’t just study one to find out about all of them. This is why we must go to look at more of them in space, otherwise we won’t be very well equipped to work out what to do if one is heading our way. At the same time, we’ll tease them into revealing some of their 4.5 billion year old secrets.
Anyway, it just so happens that June 30th coincides with me submitting the manuscript for my popular science book Catching Stardust. I hadn’t planned it this way, honest, the serendipity only occurred to me this morning. The final chapter of Catching Stardust deals with ‘Saving Planet Earth’; looking in detail at the various ways we plan to deal with space objects heading our way in the future. For now though, fear not, it looks like we’re safe for at least the next 100 years so there’s plenty of time to read my book and find out more before the big event!