Summer Nights Reveal Mysteries

The night skies of warm summer months would mesmerise sky-watchers with planets, stars, constellations and copious celestial wonders residing all over the heavens. The red planet Mars could be marvelled at in the southwestern sky after sunset till late in the night. It would be marching in the comely constellation Cancer (crab) towards the western horizon and set by midnight. The dimly baffling Beehive cluster (M44) could be manifested magnificently near neighbouring Mars. It is pleasingly 520 to 610 light-years away. The mighty planet Jupiter can be admired in the western sky after sundown. It would be jolting through the consolingly compact constellation Taurus (bull) towards the horizon till late in the night and would be evanescent. The resplendent ruddy supergiant star Aldebaran (Rohini) could be applauded below Jupiter. It is practically 65 light-years away. Perplexing planets Saturn, Neptune, Venus and Mercury could be gloriously glimpsed, but with difficulty, for a terse time in the eastern sky. They fade away from the sky as the day would break. They could be discerned dramatically as they assemble below and adjacent to the confounding circlet asterism belonging to the sprawling V-mimicking constellation Pisces (fishes). Mercury would be embracing the eastern horizon and be imperceptible. Noble Neptune could be noticed nonchalantly after mid-month. The far-flung planet Uranus would be unseen during this month. It would dive below the western horizon during dusk and slide below the eastern horizon at dawn. It would be cavorting through the commanding constellation Taurus during daytime and be lost in solar glare. Venus arrives at its greatest eastern elongation from the Sun on 31 May. Viewing Venus could be thrilling and romantic. It hovers aloft in the eastern morning sky before sunrise. Parsing entities nearby the Sun through binoculars and telescopes or even with the naked eye should be strictly avoided for preventing possible permanent damage to eyesight.

The full moon would betide on 12 May (venerated Buddha Jayanti is celebrated on this day), while the inky new moon would befall on 27 May. The full moon would be distinguished popularly as the flower full moon because during this time of the year opulent, colourful spring flowers would appear in abundance. Awesome asteroids 4 Vesta and 9 Metis would be well placed for observation in the eastern sky after nightfall. They would ascend the southern sky and eventually dip decidedly in the western sky by midnight. They would be gliding through the congenial constellation Libra (scales) and boast of a terrific tight tryst with Earth (termed perigee) on 02 and 09 May, respectively. They could be chased convincingly as a petit pin of luminous light cheerfully across the sky. Two startling stars bejewel Libra. Green-tinged bright blue white dwarf star Zubeneschamali (dubbed northern claw) is quaintly 185 light-years away. Binary bizarre star Zubenelgenubi (Vishaka), meaning the southern claw, is queerly 75 light-years away. Orange star Zubenelakrab is puzzlingly 152 light-years away. The Babylonians had deemed Libra as the weighing instrument. In Greece it was reckoned as claws of constellation Scorpius (scorpion). Today it represents a universal symbol of balance, harmony and justice.

Alluring average Eta Aquarids meteor shower would enchant avid sky-gazers with sparkling shooting stars. The Eta Aquarids would exhibit up to 60 meteors per hour at its maximum, which would transpire this year from the night of 06 May till the morning of 07 May. The meteors are allegedly spawned by debris left behind by iconic comet 1P/Halley, which had fascinated comet hunters since ancient times. Regarding the nearest moon phase, the first quarter moon will crop up on 04 May. Afterwards, there will be the waxing gibbous moon in the post-midnight sky before it sets a few hours before dawn. So the sky during mornings around the predicted peak will be tenebrous and moonless for the 2025 Eta Aquariids. The so-called radiant will rise in the wee hours, climbing toward its highest venue at daybreak. So the hours before sunup will be the best time to inspect this shower. Although the moon will block out some of the fainter meteors this year, patient onlookers would still catch some effulgent ones. The shower could be enjoyed from dark precincts away from the city after midnight. The duration of the shower is generally from 15 April to 27 May. During this time period the earth is passing through the Eta Aquariid meteor stream in space. If the paths of the Eta Aquariid meteors are traced backward, they all seem to spring out from the chic cusp in the constellation Aquarius, which on the sky’s dome is tagged as the radiant of the meteor shower. It virtually aligns with the sombre star Eta Aquarii, and the meteor shower takes its name from this star. Eta Aquarii is one of the four stars making up the Y-shaped Water Jar asterism in the northern realm of Aquarius. The alignment of the radiant and the star is, of course, coincidental. Eta Aquarii is assuredly 170 light-years away (trillions of kilometres asunder), while the Eta Aquariid meteors burn up, whooping one hundred kilometres above Earth’s surface. However, as the shower’s radiant is elevated in your sky, more meteors could be relished. For the Eta Aquariids, the radiant soars atop in the night just before dawn. One can expect to savour most meteors during the sleepy morning hours. Halley’s Comet hurtles around the Sun almost every 76 years. It returned last in 1985/86. It has been scrutinised since the year 240 BCE. Presently, it is tumbling back toward the Sun at a speed of 0.9 kilometres per second. In December of 2023, the comet reached its farthest position from the Sun. After it was pulled inexorably by the Sun’s gravity, it curved around and is heading back toward the inner solar system again. Halley’s Comet will be back in 2061. Shimmering dregs from this comet could lambently light up the night. In old times comets were contemplated as harbingers of doom, destruction and bad luck. The repeated advents of Halley ’s Comet have helped to put an end to such saddening superstitions. Peculiar planetary nebulae nicknamed Saturn Nebula (NGC 70009) and Helix Nebula (NGC 7293) narrate the story of the lives and deaths of low-mass stars and emit waves across a broad swath of the spectrum. They are strangely 5,000 and 700 light-years away. Circa seven Earth-sized rocky exoplanets are zooming around the life-flourishing area of the ultra-cool star TRAPPIST-1 that is presumably 40 light-years away. These odd objects are hosted in Aquarius.

Signs and signatures of outlandish life have been detected and reportedly revealed recently, reasonably 124 light-years away from Earth in an ocean-covered world. Using data from the famed James Webb Space Telescope (JWST), astronomers, led by the University of Cambridge, have identified the chemical fingerprints of dimethyl sulphide (DMS) and dimethyl disulphide (DMDS) molecules. On earth, these molecules are produced primarily by living microbial organisms such as marine phytoplankton. They have been ascertained in the atmosphere of exoplanet K2-18b, which is located in constellation Leo. It is orbiting a striking red dwarf star in the habitable zone, which is considered the most promising place to find life-supporting planets. K2-18b is purely 2.6 times larger and avowedly 8.6 times more massive than Earth. It is perhaps blanketed in serene sea, thus being deftly defined as a Hycean world. The planet's temperature is similar to that of Earth, but it is revolving so close to its star that one year would count just 33 days. Earlier knowledge had divulged methane and carbon dioxide in its atmosphere. It was the first time that carbon-based molecules had been ferreted out on an exoplanet. The concentrations of DMS and DMDS in K2-18b's atmosphere are different than on Earth, where they are below one billionth part by volume. On K2-18b, they are estimated to be thousands of times more intense. Hycean worlds are a unique class of exoplanets possessing key ingredients for alien species with hydrogen-rich atmospheres and vast amounts of water. Further cognisance from the JWST is needed to confirm their results are reliable and not obtained inadvertently by chance. This disclosure could be the tipping point, where suddenly the fundamental question of whether we are alone in the huge universe is one of many complex conundrums we may capably answer.

(The author is an academician at NAST and patron of Nepal Astronomical Society or NASO)