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.