30th June sees the anniversary of the largest impact by an object from outer space in recent times. The impact over Tunguska in Siberia flattened over 2000 square kilometres of forest in 1908 and the destruction was caused by a body estimated to be around 40 metres in diameter producing a shockwave with energy around 1,000 times that of the Hiroshima bomb. In more recent times, a large fireball was captured on CCTV systems and cameras on car dashboards on a February morning in 2013 over the Russian city of Chelyabinsk in the Ural mountains. 88 seconds after the fireball a large shockwave injured over 2000 individuals mainly from flying glass. The body responsible for the Chelyabinsk was around half the size of the Tunguska body at 17m in diameter.
The Solar System is home to many pieces of rock and ice that orbit the Sun like our own planet. Occasionally some of the smaller rocks cross the orbit of Earth or come a little too close and an impact occurs. Thousands of these asteroids and comets are known to astronomers but many remain undiscovered. From the fossil record it is clear to see the threat that these objects can cause with the major impact event at the Cretaceous – Tertiary (K-T) boundary resulting from an asteroid impact resulting in the extinction of around 70% of all species including famously the Dinosaurs.
Andy Exton of Hidden Horizons will be giving a lecture on the evening of 30th June at Woodend and the talk coincides with Asteroid Day. Asteroid Day is supported by many scientists across the globe and aims to educate and raise awareness of the threat that these bodies pose to Earth. The talk will cover the impacts over Tunguska and Chelyabinsk along with some other famous examples, the projects that are currently detecting these objects, those in planning and the mitigation methods should an impact be predicted. Attendees will also have the chance to examine up close a number of meteorites; lumps of rock that have fallen to Earth that are dated at around 4.5 billion years old.
Places are limited for the talk at a cost of £5 per head. Booking can be made online via our Eventbrite listing.