Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2006 May 9
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Rock Slab Growing at Mt. St. Helens Volcano
Credit: Dan Dzurisin, Cascades Volcano Observatory, USGS

Explanation: A new rock slab is growing at more than one meter a day on the Mt. St. Helens volcano in Washington, USA. The rock slab, growing since last November, now extends about 100 meters out from one of the volcano's craters. A recently made time lapse movie shows the rock slab growing. Pictured above, a helicopter examines the steaming hot rock slab late last month. Mt. St. Helens underwent a spectacular eruption in 1980 but has been undergoing a comparatively serene eruption since 2004 September. A new volcanic dome has been building which is now about 100 meters above the 1980s dome. The rock slab is visible from the Johnson Ridge Observatory on the erupting volcano.

Tomorrow's picture: cloudy sky


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