Raindrops form 'sandballs' as they roll downhill, contributing more to erosion than previously thought

What happens as a raindrop impacts bare soil has been fairly well-studied, but what happens to raindrops afterward is poorly understood. We know that the initial splash of raindrops on soil contributes to erosion, but a new study, published in the Proceedings of the National Academy of Sciences, finds that the journey of the raindrop downhill might have an even bigger impact on erosion than the initial splash.