Comet Leonard's last journey can be observed on December 12

The comet Leonard (C/2021 A1), which is heading towards the Sun, will be visible to the naked eye on December 12, an event that will be accompanied by a shower of stars, informed experts from the Institute of Astronomy of the UNAM. IA researcher and science popularizer, Julieta Fierro Gossman, explained that comets are frozen objects with different types of rocks, which contain data from the edges of the solar neighborhood.

Leonard comes from an envelope far out in the solar system, called the Oort Cloud, whose objects, unlike planets (which move in the same plane and follow elliptical orbits), can come from any direction. "Studying comets tells us what our early solar system was like when it was still a cloud of gas that later contracted and flattened to form the larger planets and the Earth," added Fierro Gossman.

The expert member of the Mexican Academy of Language explained that they shine as they approach the Sun because the ice they contain goes directly from solid to gas; that is, it sublimates, forming clouds that flash and can be seen at greater distances; they give rise to the so-called cauda, which always points in the opposite direction to our star.

Leonard C/2021 A1, which will make its last journey, was discovered by astronomer Greg Leonard, with the help of the Mount Lemmon Observatory (Arizona, United States), in January 2021, when it was beyond Mars. So far there are more than 1,600 observations made by experts that allow us to accurately calculate its trajectory and possibilities of return.

The maximum point of approach to Earth will be when it is 35 million kilometers away, which will occur on December 12, a situation that should not cause concern to the population. It will be at that moment when Mexico will have the best view of the object. Subsequently, it will be possible to observe it on January 15, approximately 30 minutes after sunset.

Fernando Avila Castro, also an IA researcher, agreed with Julieta Fierro and added that although it was said that it could return in 70,000 or 75,000 years, recent calculations reveal that it will be the last time it will cross the sky close to the sun. The promoter of the so-called Dark Skies Law commented that from December 5 or 6 it will be located in the east, approximately an hour and a half before sunrise; from December 12, towards the west; the best moment will be shortly after sunset.

If the forecasts are fulfilled, it will be possible to observe it with the naked eye in a dark place; however, in the cities, it will require a telescope due to light pollution, said the researcher. The astronomer detailed: "We can say that it is a unique opportunity because, after its passage through the closest point of the Sun, it will be ejected out of the solar system. The interaction with the different planets of the Sun has modified the orbit of this comet and, practically, we are going to say goodbye to it".

In addition to the observation of Leonard, he commented, it will be possible to appreciate the Geminids star shower, after midnight, of which 60 to 80 meteors per hour are expected. He also suggested a dark place for its sighting. Avila Castro emphasized that the main observation would be during the night of Sunday 12 when both phenomena will reach their maximum splendor.

The experts recalled that comets offer unique natural spectacles that are not usually predicted with certainty because several are observed when they are close to the solar neighborhood, although now satellite equipment, such as NEOWISE, began to detect them.