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.

September 20, 1996
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Hurricane Fran's Approach
Credit: GOES-8 Satellite, NASA

Explanation: Two weeks ago Hurricane Fran, pictured above, struck the east coast of the United States. Hurricanes are huge swirling storms with cloud systems typically larger than a state. Tropical cyclones, called Hurricanes in Earth's Western Hemisphere and Typhoons in the Eastern Hemisphere, get their immense energy from warm evaporated ocean water. As this water vapor cools and condenses, it heats the air, lowers pressure and hence causes cooler air to come swooshing in. Winds can reach over 150 miles per hour and become very dangerous. Hurricane Fran, for example, killed more than 30 people and destroyed many million of dollars worth of property. Much remains unknown about cyclones, including how they are formed and the exact path they will take.

Tomorrow's picture: The Ecliptic Plane


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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA).
NASA Technical Rep.: Sherri Calvo. Specific rights apply.
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