The chance of witnessing the spectacle is low, but not impossible. On December 18, C/2021 A1 will pass very close to the planet and two days later the trail of dust could be visible from Earth.
Every world in the solar system can, on occasion, receive debris left behind by comets in space and the phenomenon can cause spectacular light showings. These are the meteor showers, visible even from Earth. This year it could be Venus' turn to be hit by interplanetary material. An article published on the preprint server arXIV.org and sent to The Astronomical Journal also gave a date: after mid-December. The meteor shower could also be visible from our planet, although the probability is low.
Meteor shower on Venus
On Dec. 18, the recently discovered comet C/2021 A1 (Leonard) will pass just 4.34 million kilometers from Venus. Two days later, the planet will be in a position to be grazed by comet Leonard's dust trail. Meteor showers on Earth occur when our planet crosses the path of debris left behind by a comet's multiple passes over the centuries. Some of these "showers" are larger and richer than others depending on the amount of debris. In the past, for example, there have been incredible phenomena, such as the Leonid meteor shower of 1833, when 100,000 meteors per hour were seen falling from the sky.
The 1833 event was the largest recorded on Earth but not in the Solar System. In 2014, a close encounter between Mars and comet C/2013 A1 (Siding Spring) resulted in an incredible 108,000 meteors per hour raining down on the Red Planet. Only indirectly observed, the fall of interstellar material caused the meteors to produce a layer of metallic material in the Martian atmosphere. The Siding Spring passage was a less common type of rain that occurs when a long-period comet, which only rarely enters the inner solar system, passes incredibly close to a planet. In this case, it flew within 140,000 kilometers of Mars. A similar scenario could happen in the case of Venus.
The published paper indicates that the chance of seeing meteors hitting the atmosphere of Venus is very low but not impossible. The main factor for observing such a show will depend on how far the comet is from the Sun. This will also need to be rich in extremely volatile ice. Researchers are continuing to study the encounter in which some events could be visible from Earth and especially because it could be an opportunity to observe in detail a comet tail.
While the meteor shower may not be visible from Earth, on December 12, one could observe with the naked eye or binoculars the passage of Leonard before the encounter with Venus. Meanwhile, current missions to the Solar System's second planet are investigating whether its atmosphere was livable in the past.