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The largest comet in astronomical history is entering the solar system.
The National Aeronautics and Space Administration (NASA) announced on the 12th (local time) that comet ‘C/2014 UN271’ (hereafter, 2014 UN271) is currently entering the solar system.
An international research team led by Dr. David Jewitt, a professor of planetary science and astronomy at the University of California, Los Angeles, has published recent observations about the comet on the 12th of the international journal ‘Astrophysical Journal Letters’.
As measured by the Hubble Space Telescope, the central nucleus of the comet is 130 km in diameter, 50 times larger than a typical comet nucleus. It has a mass of 500 trillion tons, which is hundreds of thousands of times that of other comets close to the Sun.
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The comet is currently traveling at a speed of 35,400 km/h. By 2031, it is expected to return to the Oort cloud after approaching the Sun to about 1.6 billion km, slightly more than the distance between Earth and Saturn. The Oort cloud is a hypothetical group of celestial bodies that is said to be the origin of long-period comets, which Dutch astronomer Jan Oort announced as the origin of the long-period comet.
Astronomers view this as the starting point for all long-period comets and Halley’s comets entering the center of the solar system, as well as numerous Centaurus asteroids and Jupiter comets.
Comet 2014 UN271 was first accidentally spotted in 2010 from a distance of about 4.8 billion km. Since then, intensive observations have been made through ground and space telescopes, but it is too far away to determine the size of the nucleus surrounded by a coma of dust and gas.
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Then, on January 8, the research team used the Hubble telescope to observe the comet, which is about 3.2 billion kilometers from the sun, and took five pictures. Since it was impossible to look into the nucleus only with visible light images, data with increased light at the location of the nucleus was used. The result was obtained by removing light from the coma around the nucleus using a computer model and combining it with radio data observed with the ALMA telescope in the northern desert of Chile.
“The comet was thought to have a large nucleus because it was very bright even from a distance, but it was finally confirmed,” said Prof. “It’s been approaching the sun for over a million years in the Oort cloud, and it’s going back in the same amount of time,” he added.
Comets, on the other hand, are small bodies that regularly orbit the sun in elliptical or parabolic orbits. Unlike asteroids, which are composed of rocks (stones), comets are composed of ice and dust. Because of this, as the comet approaches the sun, its internal components melt, leaving behind a tail that glows with a green back.
By Yoon Tae-hee, staff reporter [email protected]