The Sky This Month, August
Cosmic Fireworks, Venus’s Evening Out and More!
“It’s beyond imagination until you actually get up and see it and experience it and feel it.”
- Willie McCool
Ever since the beginning of evolution of mankind till this very moment, there has never been a single day that the heavens above have failed to astonish us. Every single star out there has a million-year-long story to tell us and there are a billion of them. It is all up to us to unveil those stories.
However, the cosmos excites us occasionally by performing some feats and tricks, making it even more easier for us to acknowledge its beauty. So, let’s wait no further and explore the series of astronomical phenomena that await us this month!
Partial Solar Eclipse - August 11th
At some point in our childhood, most of us would have believed that a giant snake would engulf the Sun and the Moon occasionally and let them out after some time. This time, it’s not going to engulf, but just take a bite out of our Sun! Check out the sky at around 9:00 AM UTC to witness the wonderful sight of a partial solar eclipse. Anyway, only the people from northeastern Asia, north Europe and northern North America are fortunate enough to observe the eclipse. Disappointed? Don’t be, as there are many more breathtaking events coming up.
Perseids Meteor Shower - August 12th,13th
Brace yourselves, as Perseus, the son of Zeus commands the night sky with the splendid view of a meteor shower. This August, get ready to behold the sight of the best meteor shower of the year, the Perseids Meteor Shower. The meteor shower’s peak will be visible on the nights of August 11th and 12th and the early hours of August 13th. Set up your sky-watching equipment ready, settle down facing the northern sky in a less light polluted area and wait patiently to have the best view of the meteor shower.
Wait, a meteor shower? Sounds interesting, right? So, what exactly are they and how do they occur?
The space is filled with cosmic debris, or meteoroids. Numerous meteoroids hit the Earth every second, but most of them go unnoticed as they are merely the size of grains of sand. So, they disintegrate due to the atmospheric friction and get mixed up in the atmosphere as dust particles and probably never touch the earth’s surface. The size of meteoroids ranges from as small as a grain of sand to a few meters across. When bigger meteors hit earth’s atmosphere, they get heated up and burn, letting out radiant sparks in the night sky.
The Earth occasionally passes by the orbits of certain comets. Swift-Tuttle is one among them. With a 16-meter-wide nucleus, it is the largest known object that repeatedly passes by the Earth. It last approached Earth in 1992 and is expected to pass by again in 2126. Every year, our planet passes through the debris it leaves behind. The meteoroids from this debris hit the Earth’s atmosphere every year in the period from mid-July to August, peaking in mid-August. These meteors appear to be originating from the constellation Perseus, thus the name Perseids.
Venus at greatest elongation - August 17th
Deriving its name from the Roman goddess of love and beauty, Venus is indeed a beautiful sight in the night sky. It is the second brightest object in the night sky, with an apparent magnitude of -4.3, only next to the moon. Venus reaches its greatest eastern elongation on August 17th, 2018. Look for it in the sky after the dusk fades, at an angle of about 33⁰ above the western horizon. It will slowly sink towards the horizon and goes below at around 9:00 PM IST.
So what exactly is elongation?
A planet’s elongation is the angle subtended by the planet and the Sun at the center of the Earth. The greatest elongation of an inferior planet (a planet whose orbit is inside the Earth’s orbit) occurs when this planet’s position is at tangent to the observer on Earth. At its greatest elongation, an inferior planet appears to be at the farthest position from the Sun. If an inferior planet is visible after sunset, it is nearer to its greatest eastern elongation. If it is visible before sunrise, it is nearer to its greatest western elongation.
Full moon and Mercury at greatest western elongation - August 26th
About a week from now comes the Wolverine’s favorite day in the month - the full moon. But wait, that’s not all. Mercury, the fastest racer of our solar system (often referred to as the Swift Planet) reaches its greatest western elongation on the same day. However, it would be a little difficult to spot the little planet as it will rise just around 11⁰ above the eastern horizon, right before dawn (around 4:45 AM IST).
So that’s what the cosmos has to offer us this August. Mark your calendars and keep exploring the skies!
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Poster by Sanghamitra Vijay Anand.
