A solar eclipse and lovely planetary encounters capture our attention this June.
Quebec’s most spectacular astronomical event of the year will take place on the morning of June 10. That’s when the Moon will pass directly between the Earth and the Sun, treating us to a solar eclipse. But because the Moon is at the farthest point in its elliptical orbit, its apparent size will not be big enough to completely cover the Sun’s disc, leaving a dazzling ring of light around the Moon’s dark silhouette.
This phenomenon, known as an annular eclipse, will only be visible within a band several hundred kilometres wide, stretching from northern Ontario to Siberia via northwestern Quebec, the Canadian Arctic islands and the North Pole. Regions outside this path of annularity—elsewhere in Quebec and across most of Canada, as well as in Northern Europe and Asia—will experience a partial eclipse of the Sun.
In Quebec, the greatest challenge of this eclipse is that it unfolds in the early morning hours, around sunrise or shortly thereafter. In many places, the eclipse will already be underway when the Sun rises; in Montreal, for example, it will clear the horizon at 5:06 a.m. with a “bite” missing! Given that the eclipse takes place very low on the horizon, carefully choose a location that offers an unobstructed view of the east-northeastern horizon to ensure you don’t miss a thing.
Eclipse or no eclipse, special precautions must always be taken to protect your eyesight when observing the Sun: It doesn’t take long for the Sun’s intense radiation to cause permanent damage to your retinas. Never look directly at the Sun unless you are using approved filters, such as those in the famous “eclipse glasses.” This is even more important when observing it through an optical instrument, which further concentrates the Sun’s light: Safe solar filters for binoculars and telescopes are available from most dealers of astronomical equipment. If you don’t have an appropriate filter, there are many indirect ways of viewing the eclipse: Some are described on our official eclipse website (espacepourlavie.ca/en/eclipse2021), where you will also find details about the event, including the precise times for hundreds of locations across Quebec and Canada.
Another annular solar eclipse (partial in Canada) will occur on October 14, 2023, a few months before the highly anticipated total solar eclipse of April 8, 2024, which will notably pass through southern Quebec.
The longest days
The Sun is obviously a major topic of conversation this month. That’s because June is also when the solstice occurs, officially marking the beginning of astronomical summer. On June 20, 2021, at 11:32 p.m. EDT, the Sun will reach its northernmost point in its annual journey around the celestial sphere. In the Northern Hemisphere, it’s the day with the longest period of daylight. In Montreal, for example, there will be 15 hours and 41 minutes of theoretical sunshine on that day.
However, this does not mean that the earliest sunrise or latest sunset occur on the exact date of the solstice. As a matter of fact, there is a discrepancy of a few days due to the equation of time, the difference between the rigorously uniform time on our watches and the somewhat “flexible” time measured by sundials. The equation of time varies by several minutes during the weeks bracketing the solstice, effectively shifting sunlight hours from morning to evening. At our latitudes, the earliest sunrise actually occurs on June 15 (at 5:05 a.m. in Montreal), whereas the latest sunset happens on June 26 (at 8:47 p.m.). On June 21, the Sun will rise at 5:06 a.m. and set at 8:47 p.m.
To figure out these dates, the theoretical sunrise and sunset times must be calculated to the nearest second, while omitting non-astronomical components such as weather conditions or terrain. In the real world, however, these factors are difficult to predict and vary from day to day, but they significantly affect (by up to dozens of seconds) the exact moment when the Sun emerges or disappears at the horizon. For this reason, sunrise and sunset times are generally rounded to the nearest minute; down-to-the-second precision is unnecessary. In tables of sunrise and sunset times, you’ll note how these rounded times barely change for several days either side of the solstice.
Two planets are currently competing for our attention in the west-northwest at nightfall. Dazzling Venus appears first, shining through the veil of twilight 30 minutes after sunset, only about 10 degrees above the horizon. The beautiful Evening Star slowly sinks into the horizon, where it disappears less than an hour later.
A little higher and to the left of Venus is where you’ll find the much-fainter Mars (about 200 times dimmer), just left of Pollux and Castor in the constellation Gemini. However, you’ll have to wait for the sky to darken some more to get a good view of the Red Planet, which stands about a dozen degrees high 45 minutes after sunset and disappears below the west-northwestern horizon around 11 p.m. With every passing evening, Mars continues its eastward march against the starry background. By mid-June, use binoculars to scan the sky near the Red Planet; to its left, you’ll spot a group of tiny stars—known as the Beehive Cluster (Messier 44)—at the centre of the constellation Cancer and located 577 light-years from our Solar System. On the evening of June 23, Mars will pass directly in front of the cluster, appearing as a tiny ruby against a cascade of diamonds. There’s a narrow window of opportunity to fully enjoy the scene: After the sky grows dark enough, but before Mars and the cluster sink too low on the horizon. Try observing between 45 and 60 minutes after sunset, in the hopes that the horizon is perfectly clear that evening. The meetup is short lived, however, and the next day, Mars has already moved past the Beehive; but Venus is following closely and encounters the cluster on the evening of July 2.
Saturn and Jupiter take up the torch in the second half of the night. Saturn, currently in Capricorn, shows up first above the east-southeastern horizon at around midnight; as the hours advance, the planet climbs slowly in the southeast and culminates 27 degrees high in the south at the crack of dawn. The waning gibbous Moon will pass 5 degrees below Saturn on the night of June 26-27.
Jupiter lies about 20 degrees east (to the left) of Saturn in the neighbouring constellation Aquarius. The giant planet rises nearly an hour after Saturn and shines brightly in the southeast in the early morning hours; at dawn, it can be found about 30 degrees above the south-southeastern horizon. The waning gibbous Moon swings by Jupiter on the mornings of June 1 and 29.