A comet discovered by discovered by astronomers using the wide-field survey camera at the Zwicky Transient Facility at the Palomar Observatory in Southern California in March 2022 is approaching us this month to a point where it might just be visible with the naked eye.
After analysing the comet’s orbit, astronomers at the observatory determined it has an orbital period of 50,000 years, meaning it last came to the inner solar system during the Upper Palaeolithic period, or Old Stone Age, when Neanderthals or very early Homo Sapiens roamed the Earth. Moreover, due to the shape and angle of the comet’s orbit, this in fact will be the last time C/2022 E3 comes close to our planet.
Comet C/2022 E3 (ZTF) is predicted by the researchers who studied its trajectory to reach its perihelion – the closest it gets to the sun, on 12 January. According to Space.com, at this stage, the comet will be around 166.4 million km away from the sun, which is usually not enough to make a comet visible with the naked eye.
Comets are made of a frozen gases core, which starts to expand as it gets closer to the sun. As it expands, some of the gasses are released, along with dust. These glow in the sun’s light, forming the tails of comets. In theory, the closer the trajectory passes by the sun, the brighter the comet and more likely to be visible with the naked eye.
In the case of C/2022 E3 however, astronomers still believe it might just be visible to the naked eye when it gets closer to Earth. On 1 February, the comet will reach its perigee, the closest point to our planet, passing by at a distance of 42 million km. It is between perihelion and perigee that the comet “could become only just visible to the eye in dark night skies”, according to NASA.
The comet has two tails, one made out of dust, brighter, but shorter, and a longer dimmer one, made of ions, stretching across a 2.5-degree wide field-of-view. Whether it will be visible to the naked eye or not remains to be seen. A few lucky people in places not affected by light pollution and enjoying a clear sky might just bee able to do that, otherwise, binoculars or a telescope should do the trick. For those who still want to see C/2022 E3 pass by, but from the comfort of their own home, the Virtual Telescope Project will live stream the occurrence starting 13 January, 4:00 am GMT.