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Green comet

Astronomers recently spotted a comet using the wide-field survey camera at the Zwicky Transient Facility (ZTF) in the US, which is appearing near earth after nearly 50,000 years.

What are Green comets ?

  • Comets are frozen rocky or gas-filled objects that are remnants of the formation of the solar system.
  • The solid portions of a comet which is mostly water ice with embedded dust particles.
  • When near the sun, the icy cometary surfaces vaporise and emit large amounts of gas and dust, resulting in a massive atmosphere and tails.
  • The fluorescence of these gases, and especially the reflection of sunlight from the minute dust particles in the comet’s atmosphere and tail, is what gives these objects their visual impact.
  • Just like other bodies in space, comets also have orbits. They are sometimes pulled in close to the sun because of the sun’s gravity acting on them.
  • The orbit indicates this comet comes from the edge of our solar system, a distant reservoir of comets we call the Oort cloud.
  • The Oort cloud is thought to be a big, spherical region of outer space enveloping our sun, consisting of innumerable small objects, such as comets and asteroids.

What is the reason for the Green colour ?

  • Laboratory research has linked this green-like aura to a reactive molecule called dicarbon, which emits green light as sunlight decays it.