A green comet that took about 50,000 years to take a round of the Sun will come closest to Earth for the first time on February 2 since the Old Stone Age. This might also be the last time humans can witness the passing of the rare green comet, as it will never be sighted closest to the Earth due to its parabolic path. The C/2022 E3 (ZTF) comet is expected to be about 26 million miles from the Earth on February 2. This will be the closest the comet has been to the Earth in 50,000 years. Astronomers first spotted the comet last March. “Comet C/2022 E3 (ZTF) was discovered by astronomers using the wide-field survey camera at the Zwicky Transient Facility in early March (last year). Since then, the new long-period comet has brightened substantially and is now sweeping across the northern constellation Corona Borealis in predawn skies. It's still too dim to see without a telescope, though,” NASA said in a release on December 24. Comet Visible to Naked Eye to Approach Earth In January, February 2023; It Was Last Seen During Ice Age (View Tweet).
Earlier in the Upper Paleolithic or Old Stone Age era, it might have come closest to the Earth when humans were believed to have left Africa and settled in Asia and Europe, which contributed to the extinction of the Neanderthals. The Upper Paleolithic era was the period when the earliest known evidence of organised settlements, in the form of campsites and storage pits, was found. Artistic work blossomed, with cave paintings, carvings and engravings on bone or ivory. Comet Bigger Than Rhode Island is Headed Towards Earth; It's Fine, Says NASA.
On March 2, last year, astronomers Frank Masci and Bryce Bolin using the Zwicky Transient Facility (ZTF) at the Palomar Observatory in Southern California, came across an object that they initially identified as an asteroid, according to prominent astronomy website space.com. Subsequent observations revealed that this star-like object possessed a very tightly condensed coma, indicating that it was a comet. It was the third such object discovered in the fifth half-month (A, B, C, D, E) of 2022, so it received the designation C/2022 E3 (ZTF).
The latest orbital elements suggest that the comet is currently travelling on an orbital path with an eccentricity of 1.00027, or in other words, a parabolic orbit. Such an orbit is not closed, so after it sweeps around the Sun, C/2022 E3 will move back into deep space, never returning again. So, this will be the comet's last time to be seen closest to the Earth, the website said.

(The above story first appeared on LatestLY on Jan 10, 2023 11:56 AM IST. For more news and updates on politics, world, sports, entertainment and lifestyle, log on to our website latestly.com).