Scroll to the bottom of this article for a stargazing and astronomy calendar for Summer 2021.
The summer is one of my favorite times for stargazing. The nights are short but warm, and many people spend time camping — an ideal activity to mix with stargazing. Try looking for Sagittarius, Mercury, Jupiter, Saturn, meteor showers, and even a partial eclipse of the sun this summer. You can see almost everything I suggest below without any equipment.
Sagittarius is one of my favorite summer constellations to look for. Greek astronomers saw a centaur firing an arrow, but I always look for the teapot. At a dark enough site you can even see the steam coming out of the spout — what you are actually looking at is the Milky Way. This part of the night sky looks cloudy because there are so many faint stars close together. You are actually looking towards the center of our own galaxy and the supermassive black hole “Sagittarius A*” that lives there. The further south you go, the higher Sagittarius will be in the sky. Where I grew up, it was always quite low in the summer skies.
Some of the planets put on a show this summer. In early July, Mercury will reach its point of “Greatest Western Elongation,” which means that it is at its largest apparent separation from the Sun, and it’s the best chance you have to see it visible in the evening (just after sunset). Mercury is one of the most challenging planets to catch, because it’s always so close to the Sun, so this is a great opportunity. For a bonus, on July 11th/12th you will be able to see it next to both Venus and the crescent Moon.
The outer planets Jupiter and Saturn will also be prominent in late-summer evenings. Both will be passing through “Opposition” in August (on the 2nd and 19th respectively). What this means is that they are directly opposite the Sun in our skies — they will rise right as the Sun sets, moving up as the night goes on, and they are the closest and brightest they will appear for a while.
Meteor showers are a popular summer stargazing activity. During these events, you will see several “shooting stars” as the Earth passes through debris left behind from a comet so small that as lumps of material enter our atmosphere they burn up completely. The Delta Aquarids shower is predicted to peak July 28th/29th, and the Perseids shower Aug 12/13th. Perseids is usually one of the best meteor showers of the year, with typical rates of one meteor per minute. The best way to watch a meteor shower is to sit outside and get comfortable. Reclining chairs recommended…
My final suggestion is the only one that requires equipment and is for early risers only. On the morning of June 10th, there will be a partial eclipse of the Sun as it is rising across the East Coast of the US. In Philadelphia, the sun rises at 5:31am that morning, and the partial eclipse ends at 6:30am. You should never look directly at the Sun without a solar filter (i.e. eclipse glasses), but if you don’t have eclipse glasses, a colander can be used to great effect to project shadows of the crescent Sun. Stand with your back to the Sun, and look at the shadow cast by the colander.
Summer 2021 Astronomy Calendar
June
10th: Annular Solar Eclipse and New Moon
21st: June Solstice (Midsummer in the Northern Hemisphere)
24th: Full Moon (a “supermoon”)
July
4th: Mercury at largest Western angle (elongation) from the Sun
10th: New Moon
11th/12th: Mercury and Venus close to the crescent Moon in the evening
24th: Full Moon
28th/29th: Delta Aquarids Meteor Shower
August
2nd: Saturn at opposition (opposite the Sun on the sky from our view)
8th: New Moon
12th/13th: Perseid Meteor Shower
19th: Jupiter at opposition
22nd: Full Moon (blue moon – or an extra full moon for the season)
This article was edited by Emi Krishnamurthy and Lydia Guertin.