Look Up for A Brilliant Comet Now - Cosmic Fireworks at Play
The asteroid-hunting afterlife of the Wide-field Infrared Survey Explorer (WISE) mission discovered the Comet NEOWISE in March. The comet, which is only going to return after 7,000 years, will be closest to earth between July 22 and July 23.
For keen stargazers and astronomy enthusiasts in our country, this is an exciting time. A brilliant comet is lighting up the sky for some free cosmic entertainment.
“A new object was reported to Minor Planet Center (MPC) on March 31, 2020, by NEOWISE spacecraft that is routinely scanning the sky for near-Earth objects. Observations that followed, mostly done by amateur astronomers, confirmed that the object is showing cometary activity and their observations allowed MPC to compute the orbit and issued an online publication announcing the discovery of a new comet in April 2020. The new comet received a designation C/2020 F3 NEOWISE.” - Dr Peter Veres, an astronomer at Minor Planet Center, Harvard-Smithsonian Center for Astrophysics, USA.
Comets are ‘dirty snowballs’ which orbit our sun. In short, they consist of a lot of dust and ice. When the comet comes near the sun, the ices sublimate due to the heat of the sun and dust particles trapped in solid ice get released. This produces the beautiful tails that we associate with comets.
“NEOWISE is a big excitement this year - it is among the few brightest comets over the past 20 years or so. I would encourage anyone in the mood of seeing a comet to go outside and take a look,” reminds Dr Quanzhi Ye, research scientist at the department of astronomy, University of Maryland, USA.
This comet is about 5 km in diameter. That means it has enough water to fill millions of Olympics-sized swimming pools. At the moment, it is whizzing past us at a whooping 231,000 km per hour, which is about twice the speed at which the Earth travels around the sun.
“This is one of those rare occasions when we are lucky to witness the passage of an object from the original building blocks of our solar system. Determining the composition of comet NEOWISE will shed light on the composition of the original planetesimals that participated in the formation of solar system planets, and reveal the chemical structure of Sun's primordial nebula,” explains Dr Nader Haghighipour, a professor of astronomy at Institute for Astronomy, University of Hawaii, USA.
For the past several weeks, many top astronomers have been studying the past, present and future orbit of this comet using various numerical integration software tools and powerful supercomputers.
“Comet C/2020 F3 (NEOWISE) is definitely a "dynamically old" comet; with this expression, astronomers mean that the orbital period of the comet is not as large as would be required for the comet to come directly from the Oort cloud. Thus, the current passage of this comet in the planetary region is not its first one,” clarifies Dr Giovanni Valsecchi, an orbital dynamics expert at INAF, Rome, Italy.
This comet is only going to return after 7,000 years. So now is the best time for us to enjoy this free cometary show. On 23 July, this comet will be closest to the Earth at a distance of about 103 million km.
“It became apparent that the comet's orbit and its geometry would make this comet bright and easily observable from Earth. In the following weeks, the comet developed a dust tail and became gradually brighter. In the last two weeks of June 2020, the comet became naked-eye visible and observable early in the morning, before the sunrise,” remarks Dr Veres.
On a less cloudy night and far from light polluting city lights, all of you have to do is follow this skymap pointer from NASA (see simple sky map attached). You can find the comet near the famous constellation Big Dipper or Ursa Major. In a remote location, if it is pitch dark and when the sky is clear, one can see this comet with the naked eye. However, if you have some basic binoculars or a small telescope, the experience will be even more magical.
“In the second half of July 2020, the comet moved to the evening sky and became very bright, easily visible by a naked eye. With its curved dust tail spanning several degrees pointing opposite the direction of the Sun, it is the brightest comet on the sky since 1996-1997 when Hale-Bopp was in the sky. Currently, it is visible in the constellation of Ursa Major (Big Bear), between the asterisk of Big Dipper and horizon, ideally one or two hours after the sunset. Comet will get closest to Earth on July 23 and will start to get dimmer and start to depart the inner part of the Solar System,” adds Dr Veres.
Luckily this comet has no chance of colliding with the Earth and does not pose any danger to our planet. Hence you can be reassured that this comet is not bringing any bad omen during this challenging time. It is just a pretty celestial treat for us to enjoy during these gloomy times.
So go out and enjoy the free cosmic fireworks because you won’t be around when this comet visits us again (after 7,000 years)! Don’t miss this chance!
(The author is an affiliated astronomer at IMCCE, Paris Observatory, France)