5 Sky Events This Week: Mercury Rising, Moon Meets the Lion’s Heart

Mercury, Venus and Mars share the inner solar system with Earth and will be on display in the evening skies this week. Credit: JPL/NASA

This week skywatchers get a chance to watch the moon strike a pose with bright stars while the most elusive of naked-eye planets puts on its best sky show of the year.

Moon poses with Venus. About 30 minutes after sunset on Monday, June 10, skywatchers around the world can look towards the very low northwest for the razor-thin crescent moon to the left of Venus. Look carefully above the goddess of love for fainter Mercury forming a celestial triangle with the moon.

Surprise meteor shower? In early morning hours of Tuesday, June 11, a rare meteor shower called the Gamma Delphinids may produce a very brief outburst of activity for North American observers around 4:38 am EDT, with rates up to 60 shooting stars per hour.

While there is no guarantee, the best bet to observe any activity will be to find a dark location away from city lights and face the southern sky where the meteors will appear to radiate out from their namesake constellation, Delphinius (the dolphin) before local dawn.  Check out our full observing guide to the Gamma Delphinids.

Mercury at its best. On Wednesday, June 12, Mercury will be at its farthest possible separation from the sun in our evening sky for the entire year, positioned at its very best for mid-northern latitude observers. Riding high in the northwest at dusk, away from the glare of dusk, Mercury will be easy to find even for a novice because Venus acts as a convenient guide, appearing less than 5 degrees below (equal to the width of your three middle fingers at arm’s length).

Train even a small telescope at high power and Mercury will reveal that its disk is about 40% illuminated and looks like a miniature version of the crescent moon.

Moon joins lion’s Heart. Look towards the high southwest evening sky on Thursday, June 13, for the crescent moon hanging below the brightest star of constellation Leo, the lion.

Regulus marks the heart of the lion and lies 78 light years away. A hot blue-white star, it is about 3.5 times larger than our Sun and, at 300 million years old, is an adolescent when it comes to star lifetimes.

By the next evening, June 14, notice that the moon now has slid to the lower left of Regulus. Meanwhile southern hemisphere observers will see the crescent moon to the immediate left of the brilliant blue-white star.

after nightfall on June 14th the moon will near the brightest star in the constellation Leo, the lion. Credit: Starry Night Software/A.Fazekas
after nightfall on June 14th the moon will near the brightest star in the constellation Leo, the lion. Credit: Starry Night Software/A.Fazekas

Mars meets Aldebaran. As an observing challenge on Saturday, June 15, try hunting down the Red Planet at local dawn in the very low eastern sky near Aldebaran, the red eye of Taurus, the bull constellation.

Start your hunt about an hour before your local sunrise and look for Aldebaran to the lower right of Mars (upper right in southern hemisphere). The planet-star pair will appear higher in the sky–and therefore brighter and easier to spot–the more southerly your observing location. Binoculars will help in tracking down both objects.

While both morning stars shine with similar brightness and orange tinges, they lie at very different distances. Mars is currently stationed 369 million kilometers (229 million miles) from Earth, while the dying red giant star is a respectable 65 light years off.

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

Changing Planet

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.