High-temperature plasma in comets and its electromagnetic radiation

The possible mechanism for the generation of high-temperature plasma (T greater than about 100,000 K) in comet heads due to collisions between cometary and interplanetary grains is examined. Calculations show that plasma balls generated in such collisions at small heliocentric distances (not greater than 1 AU) will emit X-rays (h/nu/ not less than 100 eV) with an intensity of greater than about 10 to the -14th erg/sq cm s. This leads to the conclusion that X-ray astronomy can be used in the study of dusty bright comets of Mrkos 1957d type at small heliocentric distances.