Beginning March 24, 1997 the Navy and White Sands Missile Range will begin launching a series of four NASA sponsored sounding rockets to look at Comet Hale-Bopp. The launches will all take place between 8 and 9 p.m. and should be visible from surrounding communities.
Comet Hale-Bopp was discovered on the night of July 22, 1995 by two independent observers -- Dr. Alan Hale of Cloudcroft, N.M. and Tom Bopp of Glendale, Ariz.
Hale grew up in Alamogordo and graduated from high school there. He attended the U.S. Naval Academy and eventually came back to New Mexico to earn his Ph.D. in astronomy from New Mexico State. He is currently the director of the Southwest Institute for Space Research.
On the night of the discovery he was looking at two known comets with his own 16 inch reflector telescope when he stumbled on the new visitor to the solar system.
Bopp on the other hand, is an avid amateur astronomer who does not even own a telescope. On the night of the discovery he was with friends for an evening of star gazing when he discovered the fuzzy light of the comet using a borrowed telescope.
According to Hale a typical comet is a chunk of ice averaging five to 10 miles across. In addition to the water ice in a comet there is usually frozen carbon dioxide (dry ice), carbon monoxide, methane and tiny dust particles. In the 1950´s the idea of a comet being a "dirty snowball" was popularized.
In deep space the comet is nothing more than a chunk of ice. As it enters our solar system, the Sun´s heat turns frozen gases and water into gases which peel off. Many of the dust particles also flake off. This cloud of molecules and dust surrounds the comet and gives it its fuzzy appearance as it reflects sunlight. It is called the "coma."
Hale says the tail of the comet is formed when the solar winds of high energy particles from the Sun´s surface hit the coma and blow the material away from the comet.
Comets are really pretty common, but big bright ones are not. According to Hale on any given night a couple of dozen comets may be visible to astronomers with large telescopes. He says there is about one a year which is visible to the naked eye and one per decade which is really obvious to non-astronomers.
The rocket launches at White Sands are timed to view Hale-Bopp as it passes only 85 million miles from the Sun. It will reach "perihelion," it closest approach to the Sun, on March 31.
The experiments will be launched shortly after sunset on two-stage Black Brant sounding rockets. The payloads will reach altitudes from 175 to 240 miles and will land back on the missile range following a parachute decent.
The instruments being flown will look at the ultraviolet light from the coma and tail of Hale-Bopp. These observations cannot be made on Earth because the atmosphere blocks the light. Each experiment will have about five minutes for data collection.
The rocket launch dates, times and university affiliation are:
March 24, 8:15 p.m. launch, University of Colorado;
March 25, 8:45 p.m. launch, University of Wisconsin;
March 29, between 8:05 and 8.37 p.m. for launch, Southwest Research Institute, San Antonio, Tex.;
April 5, 9 p.m. launch, John Hopkins University.