The Morning Glory Pool in Yellowstone National Park, USA, on 23 August 2012. Credit: Joseph Shaw, Montana State University

Researchers at Montana State University (USA) and Brandenburg University of Applied Sciences (Germany) have come up with an explanation for the beautiful colours of hot springs in Yellowstone National Park in the USA.

They created a simple way to calculate the colours that can even visually recreate how the pools appeared years ago, before tourists began to drop coins into the pools while making wishes. (The metals in the coins affect the appearance.)

“What we were able to show is that you really don’t have to get terribly complex – you can explain some very beautiful things with relatively simple models,” said Joseph Shaw, a professor at Montana State University and one of the researchers.

The team calculated how each pool absorbs, scatters and reflects the light, taking the microbes (tiny organisms made up of just single cells) in the pools and the weather conditions into account.

Shaw said that the researchers might collaborate with biologists in the future, as the colours may provide a way to monitor the pool microbes.