Published: June 22, 2005

Note to Editors: Sommers-Bausch Observatory will be closed to the public during the evening on July 3, but reporters and photographers are welcome.

CU-Boulder's Fiske Planetarium will be open Sunday, July 3, at 11 p.m. for the public to watch as a probe from NASA's Deep Impact spacecraft slams into a comet millions of miles from Earth.

The collision between Comet Tempel 1 and the probe launched from the Deep Impact spacecraft, built by Ball Aerospace & Technologies Corp., is expected to happen at 11:52 p.m. MDT. The planetarium event is free and open to the public.

The planetarium will be tuned into NASA Television, which will be broadcasting live images of the collision, according to Doug Duncan, director of the University of Colorado at Boulder's Fiske Planetarium and Sommers-Bausch Observatory. The images from NASA TV, taken by a camera on board the Deep Impact spacecraft, will be broadcast onto the planetarium dome.

Fiske Planetarium will have telescopes set up on the front lawn for public use and will direct skygazers on where to look. Visitors also are encouraged to bring their own telescopes. The Sommers-Bausch Observatory will not be open to the public Sunday evening.

The collision, which will happen about 83 million miles from Earth, is expected to cause a sizable crater in the comet, allowing researchers to peer inside and learn more about the makeup of comets, according to Duncan. The impact of the table-size probe and the comet, which will be traveling about 23,000 miles an hour, will be bright enough for viewers on Earth to see with a telescope or binoculars.

"For those people who don't have a telescope, or who just want to watch this event, come to Fiske Planetarium and see what the spacecraft is seeing as it happens," said Duncan.

Planetary scientists from CU-Boulder will be available at the planetarium on July 3 to answer visitors' questions about comets and stargazing. The scientists will include Duncan; Josh Colwell, a research associate at CU-Boulder's Laboratory for Atmospheric and Space Physics; and Bob Pappalardo, an assistant professor in the astrophysical and planetary sciences department.

The Deep Impact spacecraft was launched on Jan. 12, 2005.

The planetarium also will host a "Deep Impact Crash Party" on July 4 from 9 a.m. to noon. Festivities will include a live broadcast of NASA's post-impact press conference and activities for children.

For more information about Fiske Planetarium and other shows and programs it offers, call (303) 492-5002 or visit the Web site at .