Physics Talk

https://commons.wikimedia.org/wiki/File:Impact_event.jpg In Part 1 ( phys-talk.blogspot.com/2020/03/planetary-defence-part-1-introduction.html ), I looked at the impacts of asteroids and comets and how to distinguish between them. The first step to protecting our planet from potentially dangerous asteroid and comet attacks is detection. This allows scientists to predict whether an object poses a threat to the Earth through orbit determination. If a hazardous near-earth object is found, the next step is the ‘implementation of measures to deflect or disrupt’ it. [1]   Detection The main method of detecting near-earth objects is through telescope observations. For instance, NASA currently supports ‘several ground-based observatories that scan the skies for asteroids’ (e.g. the Catalina Sky Survey in Arizona) [2] as part of its ‘Near-Earth Observation Program.’ At these observatories, the sky is scanned and images are taken where an asteroid, which reflects lig

E. Kolmhofer, H. Raab; Johannes-Kepler-Observatory, Linz, Austria (http://www.sternwarte.at) / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0) The Chicxulub Crater in Mexico, spanning over 110 miles in width, marks the spot where, 66 million years ago, 'an asteroid the size of a mountain' [1] struck the Earth. The asteroid travelled at a speed of around 40,000 miles per hour [1] before pummelling the planet with an 'explosive yield estimated at 100 trillion tons of TNT.' [1] This is 'two million times stronger than the most powerful man-made bomb’ [2] . The immense impact of the asteroid is believed to have caused mass extinction including that of the dinosaurs.  Although they are rare occurrences, scientists have tried to find ways to protect the planet from asteroid and comet attacks which could potentially have devastating consequences as shown by the dinosaur-ending event 66 million years ago.   Asteroids vs Comets Asteroids are