Artificial Comet

Comet, Artificial

 

a cloud of sodium vapor discharged from a space rocket at a certain point in its trajectory. It is used to facilitate optical observations of the rocket’s flight and to determine the parameters of its trajectory; it is also used for various scientific experiments. The sodium vapor, which is in an atomic state in the artificial comet cloud, intensely disperses sunlight of a certain wavelength, which permits the artificial comet to be observed using light filters even against a comparatively bright background of the sky. Artificial comets were formed during the flights of the first and second Soviet Luna space probes. At a distance of 113,000–150,000 km their brightness corresponded to the fourth-sixth stellar magnitudes. In order to form the artificial comets, the last stage of the launch vehicle was equipped with an evaporation device capable of vaporizing 1 kg of sodium in 5–7 seconds and ejecting the sodium cloud.

References in periodicals archive ?
The heavily instrumented Convair 990 jet had been used to study targets from Comet Kohoutek to terrestrial monsoons since the agency acquired it in 1973, and had photographed AMPTE's first artificial comet in December.
Enter A,PTE, the international suite of satellites (the Active Magnetospheric Particle Tracer Explorers) that made headlines two days after Christmas when it generated a cloud of barium ions in space to produce the first artificial comet (SN: 1/5/85, p.
Fortunately, Clear skies meant good viewing for the widespread observing teams (poor visibility had previously delayed the artificial comet experiment until the last possible day).