It is a tradition to look up to the sky on the night of August 10, to scrutinize the starry sky in search of falling stars and to make a wish and to hope. More than stars this is a swarm of meteorites, denominated Perseidi, which are nothing more than the debris left by the passage of the Swift-Tuttle comet, that passed close to the Earth in 1992. Its next encounter with our planet is planned for the year 2126, when, according to the forecasts, it will be visible with naked eyes. The coincidence of this astronomical phenomenon with the religious festivity of San Lorenzo is so unique to carry its name. In fact, this meteor shower is also known by the name of “tears of Saint Lorenzo”. But what is the connection between the roman martyr and the Perseidi?
Lorenzo, faithful witness to the Gospel
The Roman Martyrology thus describes the liturgical day of August 10: “Feast of Saint Lorenzo, deacon and martyr, that, desirous, as reported by Saint Leone Magno, to share the fate of pope Sixtus even in martyrdom, when he received the order to consign the treasures of the Church, he showed to the tyrant, making fun of him, the poor people that he had nourished and fed with goods begged for. Three days after he won the flames for the faith in Christ and in honour of his triumph, even the instruments of his martyrdom migrated into heaven. His body was buried in Rome in the cemetery of Verano, later honoured with his name”. In reality, we know very little of his life, if not a few anecdotes. It is certain that Lorenzo “died for Christ”, probably under the emperor Valerian, probably by means of the torment of the gridiron, on which it would have been laid and burned in the distant 258 A.D. A coincidence that has pushed the tradition to read in these stars the tears shed by the Deacon during his martyrdom. They would wander in heaven, descending on Earth every 10 August in remembrance of his death. From here the popular belief according to which all those who pray to the Saint by looking up at his “Tears” will see a their wish come true.
The Swift-Tuttle is a comet which is not dangerous for our planet, although very large: it has a diameter of almost 10 kilometres. To make a comparison, it measures approximately as much as the celestial body that over 65 million years ago collided with the Earth causing the extinction of the dinosaurs and causing a nuclear winter that lasted for centuries. The name of this meteor swarm is due to its trails: they, in fact, seem to come from the same quadrant of the celestial sphere, in this case the Constellation of Perseus. In reality, for convention, each swarm takes its name from the constellation from which the meteors seem to come. These space rocks, in the moment in which they impact with the terrestrial atmosphere, travel at about 214.365 kilometres per hour. The friction produces luminous trails (they can reach 20 kilometres in length), also visible with naked eyes in the clear blue summer sky, when they are approximately 97 kilometres from the ground. Usually, those of the Perseidi in contact with our atmosphere become as big as a grain of sand, larger rocks rarely survive the impact up to touch the ground.
How to observe them
What can you do in order to observe in the best way the “tears of Saint Lorenzo”? First of all, you must escape from the light. It is important to stand in areas where there are no buildings or other elements that cause interference with the sky as the meteors may arrive from any direction. It is recommended that you lie down, rather than sit, not only to be more comfortable but also to be able to observe a greater portion of the celestial sphere. When we observe the Universe, it is necessary to be patient: the human eye takes up to half an hour to get accustomed to the darkness and to capture the best moments of what occurs at night. It is not recommended to bring binoculars or telescopes: they allow you to observe only a small portion of the sky by reducing the chances of seeing a meteor. It is better to leave your eyes to freely move in any direction, possibly controlling often the north-east sector of the starry sky, zone from which they come. Finally, abandon the smartphones: their light disturbs the night vision even of those who are beside you, furthermore the eyes must then get used again to the dark. For one night, set aside notifications and WhatsApp messages and enjoy one of the most beautiful spectacles that nature offers us.