While the Neanderthal comet continues to approach the Earth, with its passage expected on February 1st, today a 'sister' is dangerously heading towards the Sun: it is comet 96P/Machholz, whose journey was filmed by the telescope space station Soho of NASA and the European Space Agency (ESA).
The event is out of the ordinary, since the comet will pass very close to our star, at about 18 million kilometres: for comparison, Mercury, the innermost planet of the Solar System, orbits at about 58 million kilometres, while Comet Neanderthals (C/2022 E2 ZTF) passed 166 million kilometers.
The approach to the Sun of comet 96P/Machholz taken by the Soho space telescope (source: Spaceweather.com)
Most of the comets that are found to come this close to the Sun are very small, about 10 meters in diameter, and therefore evaporate quickly.
But comet 96P/Machholz, named in honor of its discoverer Don Machholz (an amateur astronomer who died last year), measures about 6 kilometers, making it large enough to survive the extreme heat it will encounter today.
But the peculiarities of this comet do not end there: its chemical composition and the inclination of its orbit in fact cast many doubts on its origin.
This celestial object could have formed in an extremely cold region of our Solar System, beyond the orbit of Neptune, or its characteristics could be due to repeated close encounters with the Sun. But there is also a third, more intriguing hypothesis: the comet could come from beyond the confines of the Solar System.
That's why the Soho observatory will take advantage of this new passage to obtain as much data as possible: "96P is a very atypical comet, both in composition and in behavior", explains Karl Battams of the Naval Research Laboratory (NRL) in Washington, " therefore we are running a special observation program with Soho.”