Raindrops on Roses

3 January 2015

There’s a new video showing water droplets striking a bed of small glass beads. The result appears similar to impact craters from meteorites. In some ways this might seem rather childish and unscientific. There’s a common science demonstration where marbles are dropped into sand or mud to show how impact craters form. But in fact more advanced studies of impact craters often use similar experiments, just with more precision.

In the case of this work the team found that the water droplet impacts scaled with energy in much the same way that real meteorite impacts do. This is useful because it helps us frame the broad aspect of impact craters. Meteorite impacts are incredibly complex physical phenomena, so broad approximate models are necessary to get a handle on them. With these broad models we can look at things such as the lunar surface to estimate impact rates and the ages of craters. From this we can get an idea of the age and geologic activity of various planets and moons.

We’ve actually learned a great deal from studies such as these. Not just in terms of the specific aspects of craters, but also about periods of increased impact rates such as the late heavy bombardment. Combined with other evidence it helps us understand the history of our solar system.

So it might seem a little silly to drop water onto sand, but its actually serious science.