In News
- Recently discovered, Green Comet can be witnessed after nearly 50 thousand years and next expected to be seen after the same number of years.
About
- What is the ‘green comet’?
- It approached the sun in the middle of January 2023, it is now moving away from it, along its own orbit.
- The orbit indicates it 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.
- It is the most distant region of our solar system and Home of the Comets.
- Why the colour Green?
- 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.
- 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).
- 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.
- Distance from Earth:
- The green comet could be at a distance of 2.5 light minutes from Earth, meaning a “mere” 27 million miles.
- Naming:
- It will be closest to Earth in early February of 2023.
- Termed the C/2022 E3 (ZTF), the comet was named to refer to those who first spotted it – astronomers at the Zwicky Transient Facility (ZTF) in the US, in March 2022.
- Visible:
- Comets could be visible with telescopes and binoculars, and might even be visible to the naked eye under a clear night sky.
- Northern Hemisphere: Comet will be seen in the morning sky, as it moves swiftly toward the northwest during January 2023.
- Southern Hemisphere: It’ll become visible in the Southern Hemisphere in early February 2023.
- Specifically in India: In Indian skies, it can be spotted at 16° above the horizon in the Bootes constellation, when looking in the northwest direction.
- Gravity on Comets:
- 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.
- The remains of dust following this burning up, from a distance, look like a trail of light to humans on Earth.
- Comets, therefore, have often been seen giving out blue or whitish light, or even green.
- Uniqueness of Green Comet:
- It comes under the category of long-period comets, which take more than 200 years to orbit the Sun; the green comet is not easily spotted.
- With a highly elliptical orbit, the comet will head back to the Oort cloud and make its next appearance roughly 50,000 years later.
Source: IE
