Comet K2 Is Heading Towards Earth This Week, NASA Says

An exciting night awaits sky-gazers on Wednesday. A gigantic comet is passing through our solar system simultaneously as the so-called supermoon in 2022, the largest and brightest full moon ever seen. The C/2017 K2 (PanSTARRS) comet, often known as K2, is thought to be between 18 and 100 miles wide. NASA astronomers predict that it will come closest to Earth on July 13 and be most visible on July 14.

In May 2017, the NASA Hubble Space Telescope made its first observation of the K2 comet, which was located 2.4 billion kilometers from the sun between the orbits of Saturn and Uranus. According to the space agency, the comet was the farthest a comet had ever entered the planetary zone. NASA added that the Oort Cloud, a spherical layer of frozen objects with a temperature of -440 degrees Fahrenheit, is thought to have given rise to the K2 comet. Our solar system's outermost part is where the Oort Cloud is situated.

According to NASA researchers, most long-period comets, which are meteors with orbital periods longer than 200 years, are thought to originate from the Oort Cloud. The gravitational expulsion of the city-sized comet of ice and dust from the Oort Cloud may have started a trip that will last millions of years and pass by the Earth.

(Photo : C messier via Wikimedia Commons)
Messier 81 group with comet C/2017 T2, visible to the right, on May 22, 2020. The photo is created by the stacking of 42 60s ISO 800 exposures in DeepSkyStacker. The comet appears slightly elongated due to its apparent motion against the deep sky objects

Comet K2 Would Be Challenging To See With Naked Eye Despite Size

Despite the comet's enormous size, it can first be difficult to see. On July 13, it will be the closest to Earth, but it will still be around two Earth-sun distances away.

"It would easily have been a naked-eye comet had it arrived half a year earlier or later," said Quanzhi Ye, an astronomer at the University of Maryland who specializes in comets, told Space.com.

The comet's undetermined size isn't the problem for skywatchers; rather, K2 will pass relatively close to Earth.

The problem is that the intrinsic brightness (or luminosity) of the comet is determined by its distance from our planet and the quantity of sunlight striking its surface, as professional comet observer John Noonan mentioned in the same Space.com report.

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Before using the Hubble Space Telescope, Noonan, a researcher at Auburn University in Alabama, examined cometary eruptions. He claimed that surface temperature and, more broadly, the rate at which surface ices sublimate (or instantly go from solid to gas) and produce dust are both connected to comet activity.

On its way from the chilly, far-off Oort Cloud, K2 was releasing carbon monoxide that raised a lot of dust as it sublimated when it was detected in 2017. However, when it approaches our world, the comet becomes less visible.

If its activity were to increase, K2 would still be a considerable distance from our sun at its closest approach. The amount of light reflected from the dust coma that reaches our telescopes on Earth depends on distance.

According to Noonan, the comet will be almost two Earth-sun distances (1.8 astronomical units) from our planet on July 13 when it makes its closest approach. That distance from the sun is far too great to produce many sublimation and brilliant dust-lifting events.

Even when K2 makes its closest approach to the sun in December, it will still be 1.8 astronomical units outside of Mars' orbit. He claimed that K2's performance is most likely subpar due to the combined poor distance and dust output.

How to See The Comet

You can look to open-access online observatories like the Virtual Telescope Project, which will hold viewing events this week, to witness the comet for yourself. A telescope can also be obtained, and you can start using an app like Stellarium to practice seeing objects immediately. As the comet gets closer, this program will also be able to direct your lenses in the appropriate directions.

According to CNET, C/2017 K2 will fly by Earth on Dec. 17 and then go to perihelion, the closest approach to the sun, before reentering deep space. The closer a comet gets to the sun, the more unpredictable its behavior becomes. It may suddenly become active and brighter or shatter and completely vanish from view.

Whatever happens, this trip may be our only opportunity to get to know the comet. Due to its extremely lengthy orbit, it won't return for a few million years.