On this occasion, however, the traditional excursion to the heart of Teide to enjoy the astronomical spectacle has had to be suspended for many. The pandemic and the heat have forced the island authorities to control the accesses and hundreds end up turning around without seeing a single star. And, the show was somewhat higher, where the cloud of the thermal inversion could not reach.
Once you have crossed the Mirador de Matanzos, millions of stars appear to the astonishment of the most skeptical. The sky is exquisitely clean, because the Moon, which evolves towards its first quarter, barely manages to break that endemic darkness that makes any canary proud.
The silence is overwhelming. So much so that when the first wake falls from the sky there is not a soul whose cheers resonate among the mountains, something that is far from what has happened in previous years, in which each shooting star is enthusiastically celebrated by the thousands of visitors who come to the Teide National Park in mid-August. Except for the rattle of the cars authorized by the Cabildo de Tenerife, which drip down and up the road, in that dark space it is possible to feel lonely and small. The immensity of the cosmos seems to crush any brave man who dares to lie down on the earth to contemplate such a splendid natural spectacle. And at the same time, the lack of overcrowding gives a perfect moment to silently think about what I want to ask of the stars.
Surprise before midnight
The first piece of the Swift-Tuttle kite arrives shortly before midnight. A surprise, no doubt, since the maximum activity of the meteor shower was expected to begin shortly after midnight. In its long journey through the dark Canarian sky it is possible to see the fire that surrounds it due to its contact with the earth’s atmosphere. Behind it it leaves a trace of an intense green color, due to its chemical composition. “When these stones detached from the comet enter the atmosphere, a chemical reaction is triggered,” explains Miquel Serra-Ricart, director of the Teide Observatory and scientist at the Instituto de Astrofísica de Canarias (IAC), who points out that this friction with the atmosphere excites its chemical elements. In this case, oxygen is the atom that generates that characteristic greenish color of the star’s tail. “It is an effect similar to that caused by the northern lights,” emphasizes the researcher, who, however, recalls that its origins are very different. In the case of the northern lights, it is particles that excite the Earth’s atmosphere, while rocks or pieces of ice that cause it during the Perseids.
The stars continue to fall, with a power and a recurrence that nothing reminds of the previous year. “This year we can see more than 100 meteors an hour while the previous year we did not reach 80,” says Serra-Ricart. This depends on many factors, such as that the Moon is hidden or that precisely the cloud of particles that the Swift-Tuttle has left is especially thick.
A time capsule
Every year around this time, the Earth passes through a cloud of matter that is part of the trail that the meteor leaves behind in its orbit around the Sun. “The Swift-Tuttle is one of the oldest comets we know of,” says the astrophysicist . In fact, that is the reason that this meteor shower is so famous and has generated so many myths around it. «Such an ancient phenomenon goes a long way. At first it was incomprehensible, since it seemed that the stars were falling, ”says Serra-Ricart. This circumstance is what has generated myths such as the one that shooting stars grant wishes or that they are still seized as Tears of San Lorenzo.
Its age is directly related to that of the comet, which has been circling the Sun for millennia. Every year the Earth makes a trip to the past when it encounters one of these clouds, since what it passes through is matter from which the meteor detached years ago. At the moment, the researchers estimate that the Earth may be passing through the small traces of the comet that correspond to those of 1,800 or 1,900, although the date is imprecise.
The restrictions have left part of the Canarian population with the bad taste of not being able to go to see this annual show in the usual location. But there is still time and alternatives to enjoy it. The greatest activity of the Perseids will last until tomorrow and the Earth will be passing through the great cloud of matter until August 24. On the other hand, there are other locations in the Islands from which you can see the fall of stars. “On any southern beach you can enjoy this astronomical spectacle”, as Miquel Serra-Ricart points out. In fact, the researcher encourages people to go to places other than the Teide National Park in the coming days, such as the municipality of Vilaflor, since they have better access, the sky is contemplated in them with the same neatness and they generate less impact on the natural environment.
Review the show
Thanks to the Energy Efficiency Laboratories (EELabs) outreach project, the Perseids show of this year 2021 can be remembered again. The video of the broadcast that the IAC made from the Teide Observatory has been hosted on the YouTube channel of sky-live.tv. This project studies the impact of light pollution on the natural areas of Macaronesia and ensures the protection of the darkness of its skies. | VP