Perseids 2020: keys to enjoying the meteor shower

The best times to observe the Meteor Shower are the early mornings from 11 to 12 (Tuesday to Wednesday) and from 12 to 13 (Wednesday to Thursday) of August.

Let’s enjoy during these nights the most popular shower of shooting stars of the year. The best times to observe the Perseids are the early mornings from 11 to 12 (Tuesday to Wednesday) and from 12 to 13 (Wednesday to Thursday) of August.

The Moon will be in the last quarter phase and, at the beginning of the night, it will not be an impediment to see the shooting stars. To see them we only need a place protected from artificial light, a sky clear of clouds, and a little patience. Settle in comfortably, and without haste, looking at the sky in a dark place and enjoy the show.

EARLY MORNINGS ON THE 12TH AND 13TH: RAIN AT MAXIMUM

This month of August is relatively favorable for observing the Perseids as its maximum occurs while the Moon is in the last quarter phase. In the early mornings of August 12 and 13, the Moon will rise at around 1:30 am (peninsular time), so we can take advantage of the time from dusk until the Moon begins to illuminate the sky from the east. And at any time of the night, we can also locate one by looking at the darkest areas of the sky (with our back to the Moon).

The number of observable Perseids per hour is highly variable. In a very dark place and with the radiant high above the horizon it can exceed a hundred. However, the number of meteors observed per hour can vary very quickly depending on the density of fragments in the comet’s wake, so specific predictions about specific numbers of meteors depending on the day and time are difficult to make and are often affected. of high uncertainty.

The highest activity of the Perseids (measured in the number of meteors per hour) will be reached in the early mornings of Tuesday 11 to Wednesday 12 August and from 12 to Thursday 13. At those times, the number of observable meteors per hour looking towards the Zenit may exceed one hundred.

PERSEIDS UNTIL THE END OF THE MONTH

Although its peak time occurs on the nights of August 11-13, the Perseids usually begin to be seen around July 23 and end around August 22. However, as the days progress, from the 13th the activity of the Perseids will decrease. But the Moon will also lose prominence because each day it will rise later and more diminished until the new moon is reached on the 19th. For this reason, the observation of the meteors can give very good results also from the 13th, according to the nights get progressively darker.

WHAT ARE THE PERSEIDS?

Shooting stars are not stars, they are particles lost by comets. Indeed, as comets describe their orbits around the Sun, they are throwing into space a trail of gases, dust and debris (rocky materials) that remain in an orbit very similar to that of the parent comet.

Each periodic comet, throughout its repeated turns around the Sun, thus forms a ring in which innumerable fragments are found. When the Earth, in its orbital motion, encounters one of these rings, some of the rocky fragments (meteoroids) are trapped by its gravitational field and fall at high speed through the atmosphere forming a meteor shower. Friction with atmospheric gases calcines and vaporizes meteors, which appear bright for a fraction of a second, forming what are popularly called shooting stars.

The height at which a meteor becomes bright depends on the speed of penetration into the atmosphere but is usually around 100 kilometers. However, the high brightness and high transverse velocity of some meteors cause a spectacular effect, giving the observer the illusion that they are very close. Meteoroids with a mass of less than a kilogram are completely calcined in the atmosphere, but the largest and densest (rocky or metallic inconsistency) form meteorites: calcined remains that fall on the ground.

MEMORIES OF A HULKING COMET

As every year around this time, the Earth, on its way around the Sun, passes through an area populated by rocky fragments that are thrown by the periodic comet 109P / Swift-Tuttle every time it visits this region every 133 years.

The Swift-Tuttle is the largest object that regularly visits us: its massive nucleus reaches 26 kilometers in size. The Perseids were particularly active in 1992, the year this comet passed close to the Sun. The comet’s next approach to the Sun (its next perihelion) will be in the year 2126.

The Perseids are visible from across the Northern Hemisphere in midsummer. The speeds of these meteors can exceed 50 kilometers per second (180,000 kilometers per hour). Their high activity, together with the favorable atmospheric conditions for observation during the boreal summer, make the Perseids the most popular meteor shower, and the most easily observable, of those that take place throughout the year.

In order of importance of their activity, on average, the Perseids constitute the third meteor shower of those that occur in the year. Both the Quadrantids (visible in January) and the Geminids (in December) tend to generate more meteors per hour. Although they show a more irregular behavior, the Leonids (in mid-November) are usually as spectacular as the Perseids.