Enthusiastic astronomers may soon see comet C/2017 K2 (PANSTARRS), which was initially discovered in the distance in 2017, fly-by Earth on 24 July this year. At the time, the comet, known as K2 for short, was the furthest active comet ever discovered. The megacomet Bernardinelli-Bernstein, discovered last year, recently took over as the leader.


Comets are icy snowballs that orbit the sun and are composed of frozen gases, rock, and dust. When frozen, they grow to the size of a sizeable town. When a comet’s orbit brings it close to the Sun, it heats up and ejects gas and dust into a massive, blazing head that is bigger than most planets.

A comet receives enough heat while in orbit around the sun to cause the ice on its surface to melt. Thousands of kilometers from the comet’s nucleus, the tail develops and can reach great lengths. Because different wavelengths of light are reflected and absorbed by atoms differently, comet dust tails are often blue-green in color.

When will Comet K2 make its closest approach?

K2 is noteworthy for activity even when compared to one superlative. It is more common for comets to awaken near Jupiter’s orbit, considerably closer in, as opposed to when the comet first started spewing gas and dust in the far outer solar system.

Five years later, the icy body is finally drawing within reach of Earth and its enthusiastic astronomers. K2’s closest approach to our planet will be on July 14, and it will get closest to the sun on Dec. 19.

Assuming K2 survives the heated journey and continues to brighten, EarthSky predicts people with small telescopes will be able to spot the sojourner soon.

EarthSky writes, “It should brighten to magnitude 8 or even 7, still too dim for the unaided eye”.

Sharp-eyed viewers can usually spot stars of magnitude 6 in dark-sky conditions with no aid. In the case of this comet, you will also need areas away from light pollution to spot it with a telescope.

EarthSky suggests, “The darker the skies, the better the contrast will be”.

According to EarthSky, professional observatories may be able to determine the size of the comet’s nucleus when it gets closer to Earth. The nucleus of K2 was initially estimated by the Canada-France-Hawaii Telescope (CFHT) to be between 18 and 100 miles (30 and 160 kilometers) across; however, Hubble Space Telescope scans revealed it may only be 11 miles (18 km) across at most.

Earlier Comet K2 Observations

The coma (or fuzzy atmosphere) of the comet likely contains oxygen, nitrogen, carbon dioxide, and carbon monoxide, all of which turned from solid to gas as the comet warmed, according to Hubble photos from 2017.

As suggested by an archival search of CFHT imagery, K2 was active at least as far back as 2013, when it was between the orbits of Uranus and Neptune, NASA said at the time.

Astronomers say all predictions for comet activity are, however, subject to change. Comets are prone to falling apart or brightening unpredictably when the draw close to the intense heat and gravity of our sun.

But, that characteristic makes them all the more interesting to astronomers who want to understand how comets are put together.


Are Comets Potentially Hazardous as Asteroids?

The majority of asteroids and comets in our solar system are not dangerous to Earth. However, one of those objects has an orbit that crosses that of Earth for every thousand or so other objects, raising the probability of a collision in the future.

Because the energy produced by a cosmic impact grows with the square of the arriving object’s speed, a comet might have nine times more destructive force than an asteroid of the same mass.

Also Read: Spectacular Rings around a Black Hole Captured: What are they actually?

If the comet is 10 kilometers across or larger, the resulting devastation to the ecosystem will be so severe that a mass extinction, in which most living things perish, will take place (if the impact carries an energy of more than about 100 million megatons).

The fly-by of Comet K2, one of the most remarkable cosmic phenomena, will present a chance to scientists and space fans who are waiting and watching. In the coming days, researchers will have more information about the comet at their disposal.

And there is no reason to panic and jump out of your skin. Astronomers say K2 might not be a threat to you this time. All you need to do is watch for it when it comes close on July 14, 2022.

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