Galaxy over Silex Spring
Named after the Latin and French word for flint or chert, a form of cryptocrystalline silica formed in a variety of ways, including biologically mediated ones (see http://tinyurl.com/d578uuz
). It is often deposited by hot springs as they emerge into the light of day, since the temperature drop forces the silica out of solution. This form of deposit is known as sinter, and the bottom of the pool is lined with it. The water is heated by the deep seated magma gently burbling under Yellowstone National Park, that heats the rocks which it percolates through. A simple food chain is based on the thermophile bacteria that live in these hot waters, exploiting chemical and temperature gradients in order to eat. How many such simple ecologies are present in the galaxy above is a matter for conjecture…..but probably many.
Image credit: Dave Lane via EPOD