Yellowstone Grand Prismatic — Aerial Rainbow Spring

Description

Grand Prismatic Spring is the largest hot spring in the United States and the third largest in the world, and its concentric colour rings — caused by different species of heat-tolerant bacteria (thermophiles) growing at different temperature zones from the boiling centre outward — are visible from space but most dramatic from a direct overhead perspective that is impossible from the accessible boardwalks at ground level. This image was made from a research aircraft under a Yellowstone National Park aerial photography permit at 300 metres altitude directly above the spring: the deep blue centre is too hot (87°C) for any biological activity; the concentric rings of yellow Synechococcus, orange Chloroflexus, and red Oscillatoria thermophile mats ring the spring in colours that are genuinely as saturated as they appear in the photograph, with no post-processing enhancement. The steam rising from the spring creates a partial obscuration of the red outer ring.