Re:A large asteroid recently flew close to Earth
by astrodust on Monday January 09, 2017 @08:00PM
(#13361595)
K=mv^2 so a smaller asteroid going faster can do as much damage as a larger one moving more slowly.
Given the nature of orbital mechanics the speeds involved are usually staggeringly large. 20km/s sounds like a lot on a terrestrial basis, but in terms of inter-planetary motion that's downright pedestrian. The Earth itself travels 30km/s around the sun, a relatively leisurely pace as it takes a full year to complete but one orbit.
Something the size of a bus travelling at a high enough rate of speed could do tremendous damage. The Tunguska Event (https://en.wikipedia.org/wiki/Tunguska_event) is presumed to have involved an object between 60-190m in size, and that's a fairly tiny object to track at any distance, akin to trying to spot a football field.
Given the nature of orbital mechanics the speeds involved are usually staggeringly large. 20km/s sounds like a lot on a terrestrial basis, but in terms of inter-planetary motion that's downright pedestrian. The Earth itself travels 30km/s around the sun, a relatively leisurely pace as it takes a full year to complete but one orbit.
Something the size of a bus travelling at a high enough rate of speed could do tremendous damage. The Tunguska Event (https://en.wikipedia.org/wiki/Tunguska_event) is presumed to have involved an object between 60-190m in size, and that's a fairly tiny object to track at any distance, akin to trying to spot a football field.