Comets and Deep Impact Missions
A Comet is a a rock made of ice, gas and dust. It ussually has an orbit.
DATE SEEN - July 23, 1995
DISCOVERER - Alan Hale of New Mexico and Thomas Bopp of Arizona
SIZE - Was estimated to be 40 km (25 miles) across
An unusually large, bright comet was seen outside of Jupiter’s orbit. It’s intense brightness was due to its great, large size. Hale-Bopp holds the record for the longest period of naked-eye visibility.COOL FACT: It will not appear for another 2,400 years
DATE SEEN - July, 1862
DISCOVERER - Lewis Swift and Horace Tuttle
DESCRIPTION - As comet Swift-Tuttle moves closer every 120 years, it leaves behind a trail of dust which has the ingredients for fireworks. Some scientists predicted that Earth and Swift-Tuttle will hit into each other someday since their orbits closely intercept each other.
DATE SEEN - 1531 and 1607
DISCOVERER - Edmund Halley
SIZE - its 15-km (9-mile) nucleus sheds about 6 m (7 yards) of ice and rock into space.
DESCRIPTION - Edmund Halley predicted that the orbit of the comet was 76 years. Unfortunately Halley died 1742 and Edmund Halley never got to see if his prediction. The comet returned on Christmas Eve in 1758 and will come back in the inner solar system at 2061.
COMET SHOEMAKER-LEVY 9
DATE SEEN - July 16 to July 22; clues --- March 31, 1993 ; discovered
DISCOVERER - Carolyn and Eugene Shoemaker and David Levy
SIZE - 2 km (1.2 mi) in diameter
DESCRIPTION - It collided with the planet Jupiter. The impact created atmospheric plumes (thousands of kilometers high) that showed hot "bubbles" of gas.
COOL FACT - Moves 134,000 mph
DATE SEEN - January 30, 1996
DISCOVERER - Yuji Hyakutake from Japan
SIZE - 1.6 to 3.2 km (1 to 2 miles)
DESCRIPTION - Astronomers have calculated its orbit and believe that the last time it was in the inner solar system was 8,000 years ago. Its orbit will not bring it near the Sun again for about 14,000 years.