Science is Fun Fridays!

 

Have you ever noticed a green slime blob on your walkway or lawn after it rains?

It's called nostoc, or troll's butter, and is a colony of cyanobacteria.  They can live in the water or on land, from the tropics to the poles, and they often form a symbiotic relationship with nearby plants.

They can photosynthesize, fix nitrogen, withstand being frozen and thawed multiple times, and absorb UV radiation.

They can also survive drying out, known as dessication.  It will turn a dark brown color, blending in with soil, so when it gets rehydrated it seems to appear out of nowhere.

If this looks disgusting to you, don't have any fat choy, a delicacy of Chinese cuisine, often enjoyed for the Lunar New Year.  It actually looks worse cooked.