Wednesday brings a rare concentration of astronomical phenomena, a morning alignment of six planets, a partial solar eclipse before sunset, and the peak of the Perseid meteor shower in an ideally dark night.
Space enthusiasts will have their hands full today. Within the span of a single day, three separate celestial events are unfolding: an early-morning planetary alignment, a partial solar eclipse just before dusk, and the culmination of the Perseids during the night of August 12-13. The Adriatic Aerospace Association (A3) is inviting the public to use this date to bring science and technical culture closer to citizens.
The first act of the spectacle begins just before sunrise, when six planets line up along the ecliptic. The optimal time for observation is between half an hour and an hour before local dawn. Without any equipment, you can spot Saturn high in the sky, a reddish Mars, and Mercury and Jupiter near the eastern horizon. Uranus and Neptune require binoculars or a small telescope, with the help of star charts or mobile apps, according to A3.
Later in the day, just before sunset, the Moon will partially obscure the Sun's disk. While residents of northern and western Europe can count on a total eclipse, from Croatia only a partial covering will be visible, low on the western horizon. This position, A3 explains, allows for the effect of a "setting eclipse" during the golden hour.
In Zagreb and central Croatia, the partial phase begins at 7:25 PM, reaches its peak at 8:06 PM, and the Sun sets at 8:09 PM while still partially obscured. The end of the eclipse will not be visible because it occurs after the Sun has already disappeared below the horizon.
Experts emphasize that one must never look at the Sun without proper protection, neither with the naked eye, nor through sunglasses, smoked glass, or uncertified optical instruments. Only specialized filters bearing the ISO 12312-2 mark are permitted. Ignoring these measures can lead to permanent vision damage.
The final and most spectacular part of this celestial show follows during the night when the Perseids reach their maximum. Since this year's peak coincides with a new moon, moonlight will not interfere with observation, and even the smallest meteors will be visible in a completely dark sky.
According to A3 estimates, the zenithal hourly rate ranges between 80 and 100 meteors per hour. Although they can be spotted as soon as darkness falls, the most intense activity occurs after midnight and continues until dawn. No instruments are needed for observation, just look at the sky with the naked eye after your eyes adjust to the dark, which takes at least 20 to 30 minutes.
The association has appealed to local authorities to dim or turn off public lighting, especially decorative lighting on buildings and monuments, wherever it is safely feasible during that night. Besides improving observation conditions, reducing light pollution contributes to the protection of the nocturnal ecosystem, biodiversity, and human health.
While the eclipse in Croatia will be partial, Portugal is preparing for a much more dramatic sight. Around 7:30 PM in the Bragança region, a total solar eclipse will occur, day will turn into night for 25 seconds. The last time such a phenomenon was visible from mainland Portugal was in 1912.
A 100% obscuration of the Sun will only be experienced in the Montesinho Natural Park. The rest of the mainland will witness a deep partial eclipse with coverage ranging from 92 to 99 percent, while in the Azores and Madeira, that percentage will be significantly more modest, between 74 and 77 percent. The entire process begins at 6:33 PM and lasts until 8:23 PM.
Numerous public gatherings have been organized across Portugal. Centro Ciência Viva do Algarve is leading observations in Faro and Albufeira, while Centro Ciência Viva de Tavira, in collaboration with the municipality, is organizing an event at Praça da República. "During the activities, there will be a brief explanation of how solar eclipses occur, and discussions about the importance of scientific research and sky observation," the organizers say. Gatherings are also expected at Arraial and Barril beaches. In Porto, Time Out Market has prepared a themed cocktail called 'Eclipse,' and with its purchase, protective eclipse glasses are given away while supplies last.
After the eclipse, from 9:30 PM, the Portuguese will also be treated to the Perseid meteor shower. The most favorable observation period will be between 2 and 5 AM on August 13. Recommended locations include Dark Sky Alqueva in Alentejo, the Montesinho and Bragança area, and the Serra da Estrela and Peneda-Gerês mountains.
