Small raindrops, less than 1 millimeter in size (less than one-sixteenth of an inch), retain a roughly rounded shape because of surface tension, but drops can collide into each other as they are falling and form bigger raindrops. So, the water molecules in raindrops cling together, in their round little community, until… Farewell, Cloud Country The water molecules stick together because they are more attracted to bonding with each other than they are to bonding with air. Raindrops form into this shape because of the surface tension of water, which is sometimes described as a 'skin' that makes the water molecules stick together.

The drops sitting up here are like little globes of water, nearly round and spherical.

Way up high in the atmosphere, dust and smoke particles suspended in clouds create places where moisture can settle and form into drops. This short video explains how a raindrop falls through the atmosphere and why a more accurate look at raindrops can improve estimates of global precipitation.ĭownload this video in HD formats from NASA Goddard's Scientific Visualization Studio A Drop is Not a Drip

Transparent raindrop pattern