‘Green comet’ appearing close to Earth after 50,000 years
- January 25, 2023
- Posted by: OptimizeIAS Team
- Category: DPN Topics
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‘Green comet’ appearing close to Earth after 50,000 years
Subject :Science and Technology
Section: Space Technology
Context:
- The comet termed the C/2022 E3 (ZTF), is named to refer to those who first spotted it – astronomers using the wide-field survey camera at the Zwicky Transient Facility (ZTF) in the US.
Comets:
- Comets are frozen rocky or gas-filled objects that are remnants of the formation of the solar system.
- Due to their composition, characteristics and the path they move in, they tend to leave a light behind them.
Where do comets come from?
- The orbit indicates it comes from the edge of our solar system, a distant reservoir of comets known as 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.
- NASA terms it “the most distant region of our solar system” and “Home of the Comets”.
- The green comet could be at a distance of 2.5 light minutes from Earth, meaning a “mere” 27 million miles.
What is the ‘green comet’?
- Here, the comet itself is green (called the head of the comet) and emits a whitish light behind it (often called the tail of the comet).
- Comets have often been seen giving out blue or whiteish light, or even green.
- In this case, the green glow is thought to arise from the presence of diatomic carbon – pairs of carbon atoms that are bound together – in the head of the comet.
- The molecule emits green light when excited by the ultraviolet rays in solar radiation.
How rare is the green comet?
- They come under the category of long-period comets, which take more than 200 years to orbit the sun.
- As they have a highly elliptical orbit, these comets will head back to the Oort cloud and will appear again after 50,000 years.
Why do comets leave a trail of light behind them?
- 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.
- As they orbit near the Sun they heat up and spew gases and dust into a glowing head that can be larger than a planet.
- Due to their orbit near the sun, the remains of dust following this burnup, from a distance, look like a trail of light to humans on Earth.