5 Sky Events This Week: Three-Planet Huddle, Lunar Wall

As the sun sets this week and the stars come out to play, the moon makes for a convenient guidepost in tracking down some cosmic showpieces. Check out our five sky events not to miss.

Moon Joins Regulus. Starting at dusk—about 30 minutes after your local sunset—on Friday and Saturday, check out the beautiful pairing of the moon below a bright white star high in the southern sky. Located 78 light-years away, Regulus is not only the brightest member of the constellation Leo, the lion,  but according to mythology it represents the heart of the king of the jungle.

constellation picture
The moon pairs up with the bright star Regulus in the constellation Leo this week. Illustration by A.Fazekas/Starry Night Software


Moon, Jupiter, and Venus Lineup. On Monday, May 13, look for three worlds huddling very low in the western evening sky. From highest to lowest: The crescent moon, Jupiter below right, and Venus closest to the horizon. With the goddess of love setting only an hour or so after your local sunset, timing is imperative if you want to catch both planets together. (See Venus pictures.)

If  weather allows, try watching the planetary duo day to day through the rest of this month as Venus slowly climbs higher, culminating in a close encounter with Jupiter.

Arcturus, the Red Giant. After nightfall on Wednesday, May 15, gaze up at the orange-hued Arcturus, the brightest star riding high in the southeastern sky. Lying within the kite-shaped northern constellation Bootes, the herdsman, this dying red giant star sits nearly 37 light years from Earth. As a sky-watching bonus, look about 30 degrees to its lower right for Saturn and bright star Spica—both are about 30 degrees away from Arcturus, which is equal to three fist widths held at arm’s length. (See Saturn pictures.)

It’s worth training even the smallest small backyard telescope on creamy colored Saturn, as it can bring those majestic rings into clear focus.

The Lunar Wall. The first quarter moon coming into view on Saturday night is the best time of the month to view in small telescopes an amazing lunar feature called the lunar wall. A fault line that stretches 75 miles (120 kilometers) in length and is more than 1,300 feet (400 meters deep) casts a distinct straight and dark line through your eyepiece. (Read more about lunar wonders.)

The Straight Wall, or Rupes Recta, cuts across the face of the moon and is visible in small telescopes this week. Photograph courtesy JAXA/SELENE
The Straight Wall, or Rupes Recta, cuts across the face of the moon and is visible in small telescopes this week. Photograph courtesy JAXA/SELENE


Mercury At Dusk. Just after your local sunset Sunday, try to spot the the innermost planet in the solar system, Mercury. With the tiny planet only ten degrees from the western horizon this evening, you will need to have a clear line of sight right down to your local horizon with no obstructions. Binoculars will make it much easier to spot the faint, star-like world in the bright sunset glare.

Over the course of the next couple of weeks, watch as Mercury slowly climbs higher in the sunset sky as it approaches Jupiter and Venus.


Tell us—what cool sky phenomena have you seen lately?


Meet the Author
Andrew Fazekas, aka The Night Sky Guy, is a science writer, broadcaster, and lecturer who loves to share his passion for the wonders of the universe through all media. He is a regular contributor to National Geographic News and is the national cosmic correspondent for Canada’s Weather Network TV channel, space columnist for CBC Radio network, and a consultant for the Canadian Space Agency. As a member of the Royal Astronomical Society of Canada, Andrew has been observing the heavens from Montreal for over a quarter century and has never met a clear night sky he didn’t like.