Morning events include the ongoing display of four bright planets—with the moon sweeping past them May 22 through 27—and a meteor shower peaking before the first light of dawn on May 6.
Evening highlights include a glimpse of departing Mercury near a crescent moon; a family-friendly total lunar eclipse early on Sunday evening, May 15; the departure of most of winter’s bright stars; and a possible outburst of meteors on May 30.
The May 2022 Sky Calendar illustrates most of these events, both morning and evening. To view these items or to subscribe, visit www.abramsplanetarium.org/skycalendar.
A rewarding sight for early risers throughout May is the continuing fine display of four planets in the east to southeast sky, as shown on our morning mid-twilight chart below. The best time to view the four planets is actually about one hour before sunrise. The sky is in darker twilight then, about a quarter-hour before the time of our chart, when the sun is only 9 degrees below the northeast horizon. Featured in May an hour before sunup are tight pairings involving Jupiter, our solar system’s largest planet. First, Jupiter appears 0.6 degrees to the upper right of brighter Venus on May 1. The other pairing occurs on May 29, when Mars passes 0.6 degrees to the lower right of Jupiter. Each pairing is enjoyable to follow for several mornings around those dates, when the planets appear close enough for day-to-day changes to be quite noticeable.
From May 2 to 28, the order of the lineup of planets from lower left to upper right is Venus-Jupiter-Mars-Saturn. On May 29, the Mars-Jupiter pair is 28 degrees to the upper right of Venus, and 38 degrees to the lower left of Saturn. From May 30 on, the lineup is Venus-Mars-Jupiter-Saturn, awaiting the appearance of Mercury, 10 to 12 degrees to the lower left of Venus from June 11 to 30. Then all five bright planets will appear in the sky—in their actual order of increasing distance from the sun!
Other predawn rewards include the Eta Aquarid meteor shower, near peak in a dark moonless sky 1.5 hours before sunrise on May 6. The radiant of the shower is in the east-southeast, about 10 degrees above Mars and low. Meteors could flash into view anywhere in the sky, but don’t expect more than 20 per hour. These particles separated from Halley’s Comet many centuries ago; the comet itself is now 19 months before the most distant point in its 75-year orbit, beyond the orbit of Neptune, to be reached in December 2023. It will return for a nice appearance in July-August 2061. Mark your grandchildren’s calendars!
The moon returns to the morning sky on May 15, then passes Antares on May 17; Saturn on May 22; Mars and Jupiter on May 24 and 25; and Venus on May 26 and 27. Can you spot the old, 4 percent crescent moon rising 16 degrees to the lower left of Venus on May 28?
Telescopic views: The moon shows excellent detail for several mornings around last quarter phase (half-full) on May 22. Jupiter, with its four bright moons discovered by Galileo, and Saturn, with its rings now tipped 12 degrees from edge-on, are most impressive planetary sights; Saturn’s rings now appear wider than Jupiter’s disk. Venus in May shows a gibbous phase, 68 to 78 percent full, and 17 to 14 arcseconds across. Mars is a tiny 6 arcseconds across, in gibbous phase, 89 to 87 percent full. Mars’ south pole is good view, tipped 25 degrees toward Earth. It’s still spring in Mars’ southern hemisphere, so if you can get a clear, steady view with at least a 6-inch telescope at 150x-200x or more, you can catch the southern polar cap of frozen carbon dioxide. Look soon—because it’s shrinking fast: Mars reaches perihelion (closest to the sun) on June 21, and has its southern summer solstice on July 21.
At first light of dawn on May 18, about two hours before sunrise, telescopes will show the tiny 2.3-arcsecond disk of 7.9-magnitude Neptune, 0.5 degrees north of Mars.
Morning’s brightest stars (none as bright as Venus of magnitude -4 and Jupiter of magnitude -2) are Arcturus, in the west; the Summer Triangle of Vega, Altair and Deneb nearly overhead; Antares in the southwest; and Fomalhaut, low in the southeast, to the lower left of Saturn. Golden Arcturus and blue-white Vega, at magnitude 0.0, are noticeably brighter than Mars and Saturn, both near magnitude +0.8 in May.
May’s evening sky highlight is the total eclipse of the moon early on Sunday evening, May 15. As the moon rises in the east-southeast around sunset, it will already be in partial eclipse. The eclipse becomes total at 8:29 p.m. The moon’s disk will then be completely immersed in the Earth’s shadow. The sunlight that reaches the moon at that time will be dimmed and reddened by its passage through the Earth’s atmosphere on its way to the moon. From Reno, the moon will be low—only 4 degrees up—about 30 degrees south of east, with the sun just 3 degrees below the horizon, so the moon’s disk may be very difficult or impossible to see in bright twilight.
The total phase of the eclipse lasts 85 minutes; the moon will rise higher, and the sky will darken as the event progresses. The deepest and likely the darkest stage of the eclipse will occur at 9:11 p.m., when the moon passes closest to the center of the Earth’s shadow. From Reno, the moon will be less than 11 degrees up, at an earlier stage of twilight (nautical), and may be dimly seen. As the eclipse progresses, watch for the red star Antares, 14 degrees to the lower left of the moon. Total eclipse ends at 9:54 p.m., with the moon in the southeast, in a dark sky, 18 degrees up. This will likely be the brightest and most colorful view of the totally eclipsed moon.
For the next hour, until 10:55 p.m., the moon gradually exits the umbra, or dark central core of Earth’s shadow, whose circular edge will be projected upon the moon. For perhaps another 20 or so minutes after that, the dusky semi-shadow called the penumbra can be detected. The brightest—but not the closest—moon of this year may occur around 11:51 p.m., when the disk of the moon first lies entirely outside the penumbra.
The next encounter of the moon with Earth’s shadow will be another deep total eclipse, centered on 2:59 a.m. on the morning of Nov. 8.
Other evening twilight rewards include the planet Mercury, near the young moon on two evenings: On May 1, start looking for the 2 percent crescent moon just 4 degrees up in the west-northwest about 40 minutes after sunset. Very clear skies and an unobstructed view are essential. Binoculars will help you spot +0.6-magnitude Mercury some 7 degrees above the moon; the Pleiades star cluster 2 degrees to the lower right of Mercury; and Aldebaran, eye of Taurus, within 12 degrees to the upper left of Mercury. On May 2, the 6 percent moon will be higher and easier to see, 5 degrees to the upper left of Mercury, and 7 degrees to the right of Aldebaran. Mercury is fainter each evening, and will be lost in the twilight glow by week’s end.
In May, if you observe at the same stage of twilight each night, all the bright winter stars in the western sky sink a little lower. Look nightly within an hour after sunset, and watch for the disappearances of these stars, in order: Rigel, Aldebaran, Sirius and Betelgeuse. At the end of May, only the “Spring Arch” of Procyon, Pollux, Castor and Capella remains.
At dusk on May 5, look for the “Twin” stars of Gemini, Pollux and Castor, 4.5 degrees apart and 9 to 10 degrees above the fat crescent moon. On May 6, the moon has an unusually close approach to Pollux, 3 degrees from it. This can be seen during 2021-25 while the moon’s orbit is tipped northward toward the star, and when the moon passes the star while they’re above the horizon, and the sun is below. The moon’s orbit has an 18.6-year wobble (precession of the nodes), and a half-cycle from now, in nine years, the moon will pass about 13 degrees south of Pollux at each conjunction.
On May 7 at nightfall, use binoculars to locate the Beehive cluster 3 to 4 degrees to the lower left of the moon. On May 8, the moon is at first quarter phase, half full and 90 degrees from the sun. On May 9, Regulus, heart of Leo, is 5 degrees to the lower right of the 61 percent gibbous moon. On May 13, the star Spica, in Virgo, lies 5 degrees to the right of the 94 percent moon.
After May 15, you can stay up later each night to enjoy moonrise, or you can switch your viewing time to before dawn and follow the moon’s motion past Antares and four planets.
The moon is new and invisible on Monday, May 30. That evening, there may be an outburst of unusually slow meteors lasting for several minutes around 10 p.m., as Earth encounters a stream of debris from a disintegrating comet. For details, visit www.imo.net.
On Tuesday, May 31, at dusk, the young crescent moon starts a new cycle. Look for the 3 percent crescent about 7 degrees up in the west-northwest about 45 minutes after sunset.
Robert Victor originated the Abrams Planetarium’s monthly Sky Calendar in October 1968, and still produces issues occasionally, including June 2022. He enjoys being outdoors sharing the wonders of the night sky, and is hoping for the pandemic to end! Robert D. Miller, who provided the twilight charts, did graduate work in planetarium science and later astronomy and computer science at Michigan State University and remains active in research and public outreach in astronomy.