Old Faithful and Jupiter
August 29, 2008
Old Faithful doesn't just erupt during the daytime hours or when Yellowstone National Park is thick with visitors. This photo was taken well after sunset last year as Old Faithful let off steam on schedule, and when Jupiter blazed in the southern sky. The Milky Way is clearly visible to the left of Jupiter.
Geysers form when water from rain water or melting snow seeps through the rock layers and is heated by the partially molten rock of magma chambers. As the sub-surface water reaches the boiling point, small bubbles of steam form in the geyser’s plumbing system, as these bubbles rise they expand. When a critical volume of steam builds up, the remaining water is rapidly forced from the geyser system. Old Faithful has an eruptive cycle of approximately 90 minutes, a typical eruption lasts from 2-5 minutes, expels between 3,700 and 8,400 gallons (14,000 and 31,800 liters) of boiling water, and reaches a height between 100 and 180 feet (30 and 55 m).