August, the month in which half of Spain takes its holidays, is a fantastic opportunity to retire to the countryside and complete a pleasant day in nature with a little observation of the night sky and the wonders that await. That is why we have prepared this little guide , so that you do not miss any of the main events of this month and so that, for that matter, you learn a little about them.
The August sky will feature the most famous meteor shower of the year: the Perseids . This meteor shower peaks around August 12 each year, making it the 13th this year . However, its racing cars can be enjoyed from several days before and up to several days after this peak of activity. The Perseids get their name from the constellation Perseus , for that is where they seem to come from when they appear in the sky. However, its origin is closer to Earth. This meteor shower originates from Comet Swift-Tuttle , an object about 25 kilometers in diameter that completes a particularly elliptical orbit around the Sun every 133 years . This comet leaves behind, as a result of its interaction with solar light and wind, a cloud of material , which is distributed throughout its orbit. Earth passes through this cloudlet each year in August , causing the Perseid meteor shower.
Comet Swift–Tuttle’s eccentric orbit brings it slightly closer than Earth in its path around the Sun and farther away than the orbits of Neptune and Pluto . The last time this comet passed through the inner solar system was in 1992 , when it was about 170 million kilometers from our planet (farther than the Sun). This event was not visible to the naked eye, but its effects could be seen in the increased activity of the Perseid meteor shower . The next time Swift–Tuttle passes close to Earth, it will be just 22 million kilometers away, in 2126 . This comet is undoubtedly the largest of all the objects that periodically approach Earth and if it hit our planet it would cause much greater destruction than that caused by the extinction of the dinosaurs 66 million years ago. However, its orbit has been studied and it is not expected that there may be a collision with the Earth for at least the next 2,000 years.
The Perseid Meteor Shower will coincide with the full moon (which will occur on August 12 at dawn). The presence of the satellite in the sky will make it extremely difficult to observe the fireballs , making this one of the worst occasions for their observation in recent years. The new moon will not be seen until August 27.
In addition to the Perseids we will have two interesting planetary oppositions . The first of them, the most visible, will be that of Saturn . A planetary opposition is the moment in the orbit of a planet or other body in the solar system, when it is at its closest distance from Earth . This greatly facilitates its observation. Saturn’s opposition will occur on August 14 , so the surrounding days will be perfect to observe it with the naked eye and to observe its rings with a modest telescope .
We will also have opposition from the asteroid 4 Vesta , one of the largest in the asteroid belt located between Mars and Jupiter. This asteroid will reach its opposition on August 22 , reaching an apparent magnitude of 6 . This will make it difficult to locate it with the naked eye, but we can enjoy it with good binoculars or a simple telescope .
During this month we can enjoy the typical summer constellations, such as the Lyre, the Swan or the Eagle , dominated respectively by the stars Vega, Deneb and Altair , which form the famous asterism of the Summer Triangle . Also other constellations, present the rest of the year, can be seen with particular ease (because of the weather rather than the conditions of the sky itself) such as the Great Bear and Minor Bear, Cassiopeia, Cepheus or the Dragon . Also Scorpio , with the bright red Antares and the trident of stars that seem to come out of it, or Sagittarius , with its characteristic teapot shape, are easily recognizable during these dates.
During this month we will also be able to observe a peculiar event , only available to those who have a mid-range telescope, capable of distinguishing shapes on the surface of Jupiter. Specifically, we will be able to see the shadow cast by two of the gas giant’s main moons crossing the upper layers of its atmosphere. On the 9th of August we will have the shadow of Ganymede , which will be joined by the shadow of Io for a couple of hours, before the first one leaves the place. A week later, on August 16 , we will have the opposite case, in which the shadow of Io will be joined by the shadow of Ganymede for a while. Both events will occur well into the early hours of the morning.
Reference:
109P/Swift-Tuttle Orbit, Minor Planet Center, IAU, Accessed July 2022.
