NASA plans to crash a probe into this comet at 23,000 miles per hour, creating some celestial fireworks on the Fourth of July. The comet is shown in an image taken June 15 by Dr. William Keel, professor of astronomy, using a University of Alabama telescope.

TUSCALOOSA, Ala. – The University of Alabama’s physics and astronomy department will host a public sky viewing, featuring a NASA probe intentionally crashing into a comet, July 3 beginning at 9 p.m. in Gallalee Hall.

Gallalee Hall is located on the UA campus near the intersection of Hackberry Lane and University Boulevard in Tuscaloosa. The event is free and open to the public.

“Last time, ‘comet impact’ meant pieces of comet Shoemaker-Levy 9 crashing into Jupiter in the summer of 1994,” said Dr. Bill Keel, professor of astronomy. “This time, it is planned. In the early morning hours of July 4, NASA hopes to create some celestial fireworks by crashing part of its Deep Impact probe into comet Tempel 1.

“The spacecraft consists of two parts - the probe, which is the big lump of copper plus instruments and steering rockets, and a flyby section, which will sit back about 5,000 miles away and watch the impact and its aftermath using a pair of telescopes and auxiliary instruments,” said Keel.

Weather permitting; visitors will be able to see the comet, before the impact, through UA’s new 16-inch telescope.

“As seen from Tuscaloosa, the comet sets just about the time the probe reaches it at 12:52 a.m., counting the seven minutes required for the signals to reach Earth. So, we won't be able to see any effects directly,” said Keel. Live web video from NASA will be available in the Gallalee lecture hall through the time of impact.

“Whether there will be a major change in the comet depends on its structure, which Deep Impact is designed to examine,” said Keel. “How much dust is blown off the comet and how big a crater an 800-pound copper mass produces, as it strikes the surface at 23,000 miles per hour, will be seen by the other half of the spacecraft, watching from a safe distance. The event will also be scrutinized by space borne and ground-based observatories. If enough dust is blown off, the comet could brighten dramatically even as seen from Earth.”

For more information or questions about weather and event scheduling, please visit http://www.astr.ua.edu or call the department of physics and astronomy at 205/348-5050. Large groups are encouraged to call and give advanced notice so the department can plan accordingly.

The department of physics and astronomy is housed within the College of Arts and Sciences. The College is the University’s largest division and the largest public liberal arts college in the state with 6,600 students and 360 faculty. Students from the college have won numerous national awards including Rhodes Scholarships, Goldwater Scholarships, and memberships on the “USA Today” Academic All American Team.