What’s Up in the Night Sky? July 2021

Fred Barrett | Jun 30, 2021

That time of year when the days are long and the nights are short has come again. But you can’t find better months than July and August for the sheer beauty and quantity of constellations and deep sky objects to feast your eyes upon. The only catch is that observing has to begin much later than at other times of the year thanks (not) to those shorter nights. On a clear night I’ll go outside about 10 pm during June and July.

You can observe real beauties embedded in the white band of stars and dark clouds that is our Milky Way galaxy. It flows high overhead from the southern to the northern horizon.

Check out the Summer Triangle. It’s a fun challenge that can develop and improve your basic observing skills. As you move up from the southern horizon you will discover a bright star called Altair. It is in the constellation Aquila, the Eagle. Following up to the north, near the zenith, is the constellation Cygnus, the Swan. It’s shaped like a cross and at the northern end is its tail with the star Deneb shining brightly. Southwest of Cygnus is the constellation Lyra. The Greeks thought it looked similar to a guitar- like musical instrument they played called a ‘lyre’. Others nicknamed it the “Weaver” since its shape reminded them of a weaving tool to spin yarn. The intensity of the star Vega at its top is hard to miss.

The 3 stars Altair, Deneb and Vega are known as the Summer Triangle. They offer a handy reference point for finding other constellations in the summer sky.

Moving from interstellar space and back to Earth, have a look at the Moon. Binoculars or a small telescope bring out a great deal of detail on its surface. The best observing time is when the Moon is waxing or waning. Take a look at the terminator boundary between the light and dark sides. Shadows help lead the eye to complex rills and mountains and craters and provide contrast to make them more seeable.

There is one meteor shower this month – the Southern Delta Aquariids. At our latitude the radiant in Aquarius is low in the south which decreases its hourly rate from around 20 to about 10. It peaks on July 30th but unfortunately, the Moon is bright. One bonus is provided by Jupiter. It sits just above the radiant and is an alternate observing opportunity.

Venus and Mars are in the west and stay close through the month. Venus is spectacular soon after sunset and Mars is east of it but much dimmer. You will have to be fast because they set quite quickly. You should start looking the moment the Sun goes down.

The evening sky has Jupiter and Saturn in the east and they drift towards the south as the night progresses. Check this month’s highlights for more planetary observing opportunities.

I’ve always found it fascinating that the Earth is farthest away from the Sun (aphelion) in summer.

A long time friend, school mate and amateur astronomer made to me a generous donation of 4 copies of a recently published and colourfully illustrated book called “The Elements” by Theodore Gray. Within its pages you will find a beautiful visual exploration of every known atom in the Universe from Hydrogen to Krypton to Plutonium and back. Starting this month, they will be prizes for astronomy related questions that I will challenge you with in the coming months. My friend, Tom Ray, recently retired as an instructor in Electronics at Carleton University.

Are you ready? Here’s this month’s question:

Earlier in this column, I described the Summer Triangle. What galaxy is the star “shining brightly” in the Swan situated within?

I think this question is not too difficult. They are going to get tougher! Email me your answers or send them to the editor. I’ll put all the correct submissions in a hat and draw the winner. My email address is This email address is being protected from spambots. You need JavaScript enabled to view it..

Monthly Highlights

All time is EDT

July 1st: Last Quarter Moon. A brilliant Venus passes close to the Beehive star cluster M44) and is within that cluster on the 2nd. Mars is 7 degrees east.

July 5th: Earth is at aphelion – 152,100,513 Km from the Sun. The Moon is at apogee – 402,987 Km.

July 8th: An old crescent Moon is 0.5 degrees left of Mercury at evening twilight.

July 9th: New Moon.

July 12th: Venus is 0.5 degrees above and to the right of Mars in the early evening twilight - difficult. The Moon is nearby.

July 17th: First quarter Moon.

July 21st: The Moon is at perigee – 362,405 Km. Venus is 1 degree above and right of Regulus at evening twilight.

July 23rd: This Full Moon is known as the Humpback Salmon Moon. It is also the Full Hay Moon – haying time. It is also called Full Thunder Moon since most thunderstorms seem to occur in this month. Take your pick.

July 24th: The Moon, Jupiter and Saturn form a large triangle.

July 30th: Southern Delta Aquariid meteor shower peaks

July 31st: Last Quarter Moon.

Don’t forget this month’s astronomy contest! Stay safe and keep looking up!

Useful books, star charts and related items for beginners and through to advanced amateurs can be ordered from the Royal Astronomical Society of Canada at www.rasc.ca/publications. A subscription to our very own excellent Canadian astronomy magazine “SkyNews” can be arranged at the RASC website as well.

Let me know how your observing has gone this month, especially anything unusual. I enjoy the feedback. If you have any questions or suggestions you can contact me through this paper or email me at This email address is being protected from spambots. You need JavaScript enabled to view it. . Clear Skies! Fred