Comet ISON Starts Sublimation, Turns Green

The nucleus of comet ISON, a.k.a, the comet of the century, appears green in its recent images, which points toward the comet getting livelier as it gets closer to our Sun. The comet has started experiencing the process of sublimation.

Sublimation refers to the process of solid matter transforming directly into gas.

This celestial guest has been putting up an interesting fireworks display in the sky and treating the stargazers. This Sun grazing comet will pass by the perihelion of the Sun. The comet is expected to be about 730,000 miles above the surface of the Sun on Nov. 28 and Earth will be able to see it by early December. ISON is expected to stay strong and remain intact even after passing by the Sun.

As it gets closer to the Sun, the sublimation rate of the comet increases. The Sun's heat will envelope this dust-bleeding, cold comet in a temporary atmosphere comprising of dust, ammonia, carbon dioxide and other gases.

This heating also leads to the production of two more colorless, poisonous gases called diatomic carbon and cyanogens, according to a Universe Today report.

The toxic Cyanogen gas smells like almonds, and comprises of a carbon atom and nitrogen atom. The other gas, Diatomic, on the other hand, stinks and consists of 2 carbon atoms. Both these gases trigger light green illumination.

This comet was discovered by two Russian astronomers named Artyom Novichonok and Vitali Nevski from International Scientific Optical Network (ISON) and hence, the  name ISON. These astronomers spotted the comet with the help of a 0.4-meter (16 in) reflector.