by Geoff Chester, USNO Public Affairs | 08 June 2021 Messier 51, the "Whirlpool Galaxy" in Canes Venatici, with companion galaxy NGC5195 imaged 2021 May 8 from Mollusk, Virginia with an Explore Scientific AR102 10.2-cm (4-inch) f/6.5 refractor and a Canon EOS Rebel T2i DSLR. The Moon returns to the evening sky this week, waxing through her crescent phases as she springs up from the western horizon. Look for her very thin crescent close to bright Venus in the twilight of the evening of the 11th. Two nights later Luna passes near Mars to the east of the stars Castor and Pollux in Gemini. She ends the week near the bright star Regulus in the constellation of Leo. New Moon occurs on the morning of the 10th at 6:52 am Eastern Daylight Time. This particular New Moon also produces one of the year’s two solar eclipses. This one will be an annular, or “ring of fire” eclipse, with the central path crossing the arctic regions from Hudson Bay to northwestern Greenland, then across the pole to eastern Siberia. Here in Washington the Sun will rise shortly after greatest eclipse, with about 70% of his disc covered by that of the Moon. As Old Sol rises higher the Moon will slip farther to the east, and the eclipse, such as it is, will end 45 minutes later. Locations farther north and east will have better views, but only the partial phases will be visible from the United States. Maximum obscuration will be visible from northern Minnesota and the Upper Peninsula of Michigan, but even at these locations the Sun is only partially obscured. As with any solar eclipse, I cannot over-stress the need for proper eye protection. If you observe with the unaided eye you can look safely for a few moments right at sunrise, but your best bet is to use a pinhole projector or “eclipse glasses” one the Sun climbs a few degrees. If you are using a telescope or binoculars, cover the objectives with an approved solar filter. We are now entering the two-week “season” of phenomena associated with the summer solstice. We will see the year’s earliest sunrise here in Washington on the morning of the 14th, when the Sun peeks over the eastern horizon at 5:42 am EDT. By the time of the solstice itself Sunrise will be a minute later, but the times of sunset will continue to creep a bit later in the evening. We will see our latest sunset on the 28th, when Old Sol slips below the west horizon at 8:38 pm EDT. The short nights of June offer a bounty of interesting celestial sights so long as you don’t mind the late start to full astronomical darkness. The first part of the evening sky hosts a number of fairly bright external galaxies which can be glimpsed from suburban locations with modest telescopes. Beyond the stars of Leo, Virgo, and Ursa Major lie thousands of these distant “island universes” at distances that boggle the imagination. Although they appear to be little more than featureless smudges in the eyepiece, in reality they shine with the combined light of hundreds of billions of stars. One of my favorites is Messier 51, the “Whirlpool Galaxy”, which lies just over three degrees southwest of Alkaid, the star that marks the end of the “handle” of the Big Dipper. A small telescope under dark skies will reveal two fuzzy swatches of light against a velvet background sprinkled with stars. Larger telescopes will begin to show a spiral structure to the larger of the two galaxies which led astronomers of the 19th Century to give it its name. It is one of the most photogenic galaxies in the sky, having been imaged by thousands of amateur astronomers, professionals, and the Hubble Space Telescope. The Whirlpool lies at a distance of about 31 million light-years and is thought to be about half the size of our Milky Way galaxy. Venus continues to work her way eastward from the Sun as she traverses the stars of the constellation of Gemini, the Twins. You should be able to easily locate her bright glow about an hour after sunset, when she is around five degrees above the west-northwest horizon. The sharp sliver of the young crescent Moon lies just to the right of Venus on the evening of the 11th. Ruddy Mars has now entered the seemingly blank area of the sky between Gemini and Leo. There’s actually a constellation there, Cancer the Crab, but it is hard to locate under urban skies. The Moon lies about four degrees northeast of the red planet on the evening of the 13th. Saturn has finally cracked the evening sky barrier, rising before midnight in the southeast. Jupiter follows the ringed planet into the sky about an hour later. Your best view of them will still be in the wee morning hours, though, where you will find them due south at the onset of morning twilight.