Asteroid impacts are among the most feared of natural catastrophes. So estimating the risk they pose to humanity is an important task.
One method is to look at the number of impacts in the past and use this as a guide to the future. This isn’t entirely straightforward since the distribution of crater sizes we see today depends not only on the rate of impact in the past but also on the rate of disappearance via processes such as erosion, tectonic changes, obliteration by other craters and so on.
Nevertheless, various groups have measured the distribution of crater sizes and come up with estimates of future impact probabilities.
Today. William Bruckman and pals at the University of Puerto Rico at Humacao do exactly this kind of analysis but with a twist. They derive impact probabilities for Earth but also for Mars. Their conclusion is that astronauts visiting Mars for just a few years are likely to witness a significant asteroid impact.To read more, click here.