About 11 months ago, in March of last year, two American astronomers used the transiting “Zwicky Facility” in southern California to discover the “green comet”.
At the time of the discovery of this comet, it was located within the orbit of Jupiter, approximately 400 million miles (643 million km) from the sun, but it passed during the first of February, near the Earth.
And astronomical calculations revealed that this is the first approach in 50,000 years, which means that the last time he passed near the Earth, Homo sapiens were still sharing the planet with Neanderthals.
Is there an opportunity to witness this comet again, for those who missed watching the last approach, and why was this comet called green, and what is the story of its discovery?
These and other questions are answered by astronomer Bryce Bolin, a postdoctoral researcher at Goddard Space Flight Center and one of the comet’s discoverers, in an interview.
* Beginning: What is the story behind the discovery of this comet?
** In March 2022, we observed a faint object “about 25,000 times fainter than the dim stars that can be seen with the naked eye,” and that was about 399 million miles (642 million km) from the sun, or within the orbit of Jupiter, and we quickly reached That it has a distinctive tail, which proves that the body was, in fact, a comet and not an asteroid, because asteroids are rocky bodies, while comets consist of ice and dust particles that gradually evaporate as the comet approaches the sun, which creates a visible effect, and both types of bodies revolve around the sun.
By January 12, 2023, the comet had approached Earth by about 300 million miles (482 million km), and it became visible in the night sky near the constellation ‘Northern Corona’ as it approached the sun, and an explosion of solar particles called coronal mass ejection spread over the comet. He tore off part of his tail.
* And why was the first of February identified as the best time to see the comet?
** For professional observers, they didn’t have to wait until February 1. On January 12, they took a closer look at the comet as it approached its closest point to the sun (a phenomenon called perihelion), and at night On January 26 and 27, the comet was visible east of the constellation Ursa Minor, and on the 30th of the same month, the comet had a peak brightness of +4.6, which means that it was slightly brighter than the weakest objects visible to the naked eye, and the comet’s brightness increased even more as it approached. From Earth, by the first of this February, when the comet approached Earth, at a distance of 28 million miles (45 million km), and it was then near the constellation “Giraffe”, and a few days later, on the 5th and 6th of this month, the comet passed To the west of the star ‘Cappella’, then enters the constellation ‘Auriga’.
Was it possible to see this comet with the naked eye?
**This required an area with dark and clear skies, so if the area where you live has high light pollution, it cannot be seen with the naked eye.
Why was it called the “green comet”?
** The comet itself is not green, but its head glows green thanks to a fairly rare chemical reaction, and the glow likely comes from diatomic carbon (C2), a simple molecule made of two carbon atoms bonded together, when the incoming ultraviolet rays break From the sun this molecule, they emit a green glow that can last for several days.
* And for those who missed seeing this ‘green comet’, when will be the next occasion for its approach to Earth?
** The comet’s last trip was its first approach to Earth 50,000 years ago, which means that the last time it passed near Earth, Homo sapiens were still sharing the planet with Neanderthals, and we are not sure exactly to what extent The comet will travel after leaving the Earth behind this time, but it seems that it is on its way to leave our solar system completely, and therefore we may not see it again, and there is a possibility that the gravity of some unknown objects in deep space will change the orbit of the comet slightly, which will return it to a path that passes through our solar system, but if that happens, it will likely be millions of years before the comet approaches Earth again.
