Here is a great astronomy website for some fun this weekend called Down2Earth. You input some parameters and then simulate an asteroid impact (onto Wales no less). You can select the asteroid’s size, speed, density and target material (water or two types of land).
I decided to see what would happen if a 5km asteroid hit the Earth at high speed and landed in water. I’ve been kind and given the asteroid a ‘dense rock’ constitution rather than solid iron.
The above image shows the size of the resulting crater compared to Wales. I’ve centered it on the unfortunate, small town of Builth Wells. Poor buggars. As you can see, the crater is somewhat large!
The crater’s depth is enough to sit several Empire State Buildings inside it. You can also compare the size of the crater to several other famous landmarks.
The site also returns several facts and figures, including the kind of damage that would be caused at different distances from the impact site. As you can see here, the damage would be felt across the UK and Europe. This isn’t even the biggest or densest asteroid that can be simulated.
Go and try it out! Down2Earth can also be used in Spanish and German. It was created by some fellows (not me!) who can often be found lurking in the John Barrowman and David Tennant suites of Cardiff University.