With its warmer weather and clearer nights, June is the perfect month to head outside for some stargazing.
Even though the nights are the shortest of the year — the summer solstice occurs on June 21 at 11:54 a.m. EDT — June’s milder temperatures lend themselves well to cozy evenings spent outdoors, exploring our starry skies. Sure, you’ll encounter a few pesky flies and mosquitoes, but what a small price to pay for soaking in the vastness of the heavens.
So, what’s there to see? All kinds of constellations, for one thing. But how do we find them? By looking for Ursa Major or, more specifically, the asterism popularly known as the Big Dipper. An asterism is a grouping of stars that forms a more recognizable shape or pattern. Although the whole of Ursa Major, with its some 216 stars, is difficult to see in the city, the seven brightest stars that form the Big Dipper are easier to spot. Ursa Major is circumpolar, meaning it never sets below the horizon at our latitudes and can be seen every night of the year. We can use the asterism as a guide to help locate four other constellations in the June sky.
At this time of the year, you’ll find the Big Dipper very high in the northwestern sky around nightfall. Follow the arc of the Big Dipper’s handle southward directly to Alpha Boötis, or Arcturus, the fourth brightest star in the night sky. Its name comes from the Ancient Greek meaning “guardian of the bear”! The constellation Boötes extends northeast and its asterism resembles an upside-down necktie, with the beautiful red giant Arcturus forming the knot. The shape of this constellation is, in fact, a playground for the imagination. Some say Boötes looks more like a kite. One legend depicts it as a herdsman, another as the inventor of the plough… As I enjoy balmy summer nights under the stars, with my feet dangling off the dock, I prefer to conjure up the version where Boötes is taken to represent Icarius, a grape grower who invited the god Dionysus (known as Bacchus to the Romans) to visit his vineyard; the god was so impressed that he taught Icarius the art of winemaking...
Now turn your gaze slightly to the east (left), where you will see Corona Borealis, one of the loveliest constellations of the Northern Hemisphere. This dazzling C-shaped assemblage of stars, laying on its side, looks like a crown with its brightest star, Alphecca, forming the top jewel. The goddess Aphrodite offered it to the sea nymph Thetis as a wedding gift. Dionysus—him again!—tossed the crown into the sky to seduce Ariadne.
Finally, immediately east (to the left) of Corona Borealis lies the constellation Hercules, appearing in this area of the sky as a trapezoid-shaped asterism that represents the demigod’s torso. Under his right armpit lies M13, a great globular cluster of over 500,000 stars almost as old as our Galaxy itself and just detectable to the naked eye, although a telescope will reveal it in all its splendour!
Let’s go back to our Big Dipper. Draw a line from the two stars that form the end of the pan (opposite the handle), extend it northward by a factor of five and you’ll arrive at Polaris, the apparent axis of rotation of all the stars in the sky, located at the end of the Little Dipper’s handle, in Ursa Minor.
The planets in June
June evenings will be your last chance to view Mars until the fall. The sun is actually catching up to the red planet, which appears lower and lower at twilight: By mid-month, the planet is visible less than 10 degrees above the west-northwestern horizon one hour after sunset, and disappears completely around 10:30 p.m. Mercury makes an interesting appearance in the evening sky this month. Use binoculars to scan the west-northwestern horizon 30 minutes after sunset: The tiny planet will appear as a small spot of light in the twilight glow. Mercury and Mars move ever closer with each passing evening and will be in conjunction after mid-June: less than one third of a degree apart on the evening of the 18th. Mercury currently outshines Mars.
Jupiter is at opposition on June 10, meaning it’s diametrically opposite the sun in the sky. The giant planet rises in the southeast at dusk, culminates in the south in the middle of the night, and sets in the southwest at dawn. The other giant planet, Saturn, is currently about 30 degrees farther east and trails Jupiter in the sky by just a couple of hours.
As for Venus, it rises less than one hour before the sun. The dazzling Morning Star can be found less than 5 degrees above the east-northeastern horizon approximately 20 minutes before dawn. On the morning of June 1, the lunar crescent lies 6½ degrees to the right of Venus, low over the east-northeastern horizon.
The Moon can serve as a guidepost to help us find the other planets. On the evening of June 4, the thin crescent moon will hang 5½ degrees to the left of Mercury and will appear 5½ degrees to the upper left of Mars the evening of the 5th. At around 11 p.m. on June 15, the waxing gibbous moon will be just west (to the right) of Jupiter. The following evening, on the 16th, the moon will be full (this phase is reached in the early hours of June 17, at exactly 4:31 a.m. EDT), and will shine to the immediate left of the giant planet. And on the evening of June 18, again around 11 p.m., the waning gibbous moon will appear directly below Saturn.
Saint-Jean-Baptiste Day marks David Saint-Jacques’s return to Earth. He will leave the International Space Station (ISS) on June 24 after 203 days spent in orbit, making this the longest mission on board the ISS for a Canadian astronaut. We’re looking forward to welcoming him back!