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    Tuesday, April 16, 2024

    In praise of multiples

    The whole point of amateur astronomy is to stare at cool stuff in the sky millions, billions, and trillions - or in the moon's case, just thousands - of miles away. We can view dappled craters on a crescent moon, the rusty glow of Mars, Saturn's distinctive rings and the cloud bands on Jupiter, among other celestial bodies. The stars are just points of white light to the naked eye, but through a lens their colors emerge. Red giants, searing blue newborns, yellow suns, white dwarves.

    Stars come in many forms, too. Star clusters show where hundreds or thousands of stars hang together bound by one another's gravity, born from the same explosion of matter in the distant past. Many stars are pairs or triplets and orbit one another at various speeds.

    A particularly rewarding night with a telescope or binoculars will include a conjunction, like the one coming up before dawn on Monday, Aug. 18. Venus and Jupiter will appear to be almost touching in the pre-dawn sky just a quarter of a degree apart. Look in the east, the same direction as the sunrise.

    As an added bonus, the beehive star cluster will sit just one degree from the pair of planets. A glance with just your eyeballs will yield a pleasing sight of the two planets, which will look like extremely bright stars, but a telescope or binocs will take the sight to a whole new dimension and allow you to observe the beehive cluster. The stars in this cluster are pretty young - about 600 million years old - and the cluster itself lies quite close, compared to other star clusters, at roughly 600 light years.

    Two years ago, two planets were discovered orbiting separate stars in the Beehive Cluster. They were the first planets orbiting stars like our sun that were actually within a star cluster. Planets had been found in star clusters before, but they weren't orbiting sun-like stars - and in the ongoing quest to find other life in the universe, sun-like stars are key.

    As for the upcoming conjunction, Jupiter's cloud bands will be revealed through a telescope, as will Venus's blue hue and moonlike phases. Because Venus, like the moon, is between Earth and the sun it has phases like the moon: crescent, full, waxing, waning and gibbous. On Aug. 18 it should appear as a crescent.

    localuniverse@msn.com

    Sky calendar

    Aug. 10: Full moon. This is the closest and largest full moon of the year, an annual event hyped as a supermoon. In reality, it is only slightly larger and brighter than normal and the difference is almost unnoticeable.

    Aug. 12, 13: Perseids meteor shower. This is one of the best, producing up to 60 meteors an hour, many of them quite bright. The waning gibbous moon will block out some meteors, but the Perseids are so bright and numerous that it shouldn't rain on the parade. Best views will be after midnight from a dark location away from light pollution. Meteors will radiate from the constellation Perseus, but can appear anywhere.

    Aug. 18: Conjunction of Venus and Jupiter.

    Aug. 25: New moon. This is the best time of the month to observe faint objects like galaxies and star clusters because there is no moonlight to interfere.

    Aug. 29: Neptune at opposition. The blue giant planet will be at its closest approach to Earth and its face will be fully illuminated by the sun. However, its vast distance from Earth means it will only appear as a tiny blue dot in all but the most powerful telescopes.

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