Planets, asteroids, and meteors – oh my! August is one of the best night months of the year for astronomical events. This is primarily due to the Perseids, arguably the best meteor shower of the year. But the Perseids aren’t the only thing worth seeing in the night sky this month. The August night sky has plenty else to see.
Before jumping into the list of night sky events in August, I want to provide some recommendations for telescopes and binoculars; some of the events this month will require having one if you want to see them. If you need a telescope to help enjoy any of this month’s night sky events, we have a guide to the best stargazing telescopes. We also have guides based on price, whether you want to buy a solid telescope under $300 or splurge on a one of the best telescopes under $1,000 instead. If you’d rather use astronomical binoculars, I have a guide to binoculars under $1000. (More guides at lower price points are coming soon!)
Okay without further ado, let’s jump into the astronomical events in the August night sky. Here are all the planets, asteroids, and meteors – and a brand new comet – you can mark on your calendar for some epic stargazing this month.
Did you know? These are some of the best stargazing events this month – but there are many other interesting events and good nights for stargazing all year long.
Learn more and get your copy of The Night Sky in 2021: When to Go Stargazing All Year Long for just $3.99 (on sale from $7.99).
Featured photo credit: Logan Brumm via Flickr
August 1 – Saturn at Opposition
August starts off quietly, but with one major astronomical event worth seeing: Saturn will be at opposition on the night of August 1st!
What does this mean? For those not familiar with the term, it means that Saturn will be directly opposite from the sun in the sky – or that the earth is exactly lined up with the sun on one side and Saturn on the other. This means that from our perspective on the night of the 1st, Saturn in the night sky will be brightly illuminated by the sun shining on the earth’s daytime side. (It’s a great night to try and see Saturn!)
The moon will be 29% illuminated on this night, so it shouldn’t interfere much if you pull out your telescope or astronomical binoculars to spot Saturn and its lovely rings.
August 5 – Comet C/2021 O1 Nishimura at its Closest
Comet C/2021 O1 (Nishimura) was discovered on July 21st – so recently that I had to come back and update this post to add it! It was discovered by Japanese astronomers, hence the name Nishimura.
On August 5th, it will be at its closest to earth, 158 million miles away. This comet is currently visible in morning twilight, so if you want to try and image C/2021 O1 Nishimura, this is one of the last days you’ll have a chance before it is lost in the sun. (After reaching perihelion on August 12th, this comet moves away and will not be any easier to see.)
August 10 – Conjunction of the Moon & Venus
After a quiet first week of August, the astronomical events in this month’s night sky kick off starting on the 10th. On this night, the Moon and Venus will have a close approach.
(For clarity, a close approach or “appluse” means that the two will appear together in the sky; a conjunction means that they rise at the same right ascension.)
The Moon and Venus will pass within 4°17′ of one another on the night of August 10th. This is too far apart to view through a telescope or binocular view, but don’t let that dissuade you. Venus is bright and the Moon will be only 11% illuminated making it a perfect night to view them both.
August 12 – Peak of the Perseid Meteor Shower
If you love the night sky, you already know what makes the night of August 12th so special – it’s the peak of the Perseids! The Perseids meteor shower peaks every year in mid-August; in 2021, this peak is expected to occur in the early morning hours of August 12th. At its peak, you can expect to see up to 150 meteors per hour! This, combined with warm weather in the northern hemisphere, makes it the most popular meteor shower of the year.
The Perseids Meteor Shower is caused when the Earth passes through a stream of debris left by the Comet 109P/Swift-Tuttle. Swift-Tuttle has a 133-year orbital period, but we experience a yearly meteor shower due to variations in the earth’s orbit and width of the debris stream.
To spot the Perseids, look for them radiating from a point in the northeastern sky. Unlike last year when a nearly-full moon interfered with viewing prospects, this year the moon will be only 27% illuminated and offer much less light pollution in the sky.
August 12 – Asteroid 349 Dembowska at Opposition
August is a big month of asteroids! There are three asteroids you can see in the night sky this month, the first of which is asteroid 349 Dembowska on the night of August 12th.
This large, 140km-diameter asteroid was originally discovered in 1892. 349 Dembowska is also very bright, with an albedo (brightness score) that is second only to Vesta for an asteroid of its size.
One important thing I forgot to mention: this is a great one for you stargazers in the southern hemisphere! 349 Dembowska will be visible in the constellation Piscis Austrinus, and a 25% illuminated moon won’t get in your way of using a telescope or binoculars to spot this distant solar system body.
August 18 – Peak of the κ-Cygnid Meteor Shower
The second meteor shower in August will occur on the night of August 18th. On this night, you can look for the peak of the κ-Cygnid meteor shower at a rate of roughly 3 meteors per hour. This meteor shower is not as bombastic as the Perseids a few days earlier, but the moon will be only 1% illuminated – nearly new – and ideal for a night of stargazing and meteor spotting, even if those shooting stars are quite infrequent.
To spot κ-Cygnid meteors, look for the constellations of Draco near Cygnus (with its distinctive cross asterism). On the 18th, κ-Cygnid meteors will appear to radiate from this area of the sky, high above the northeastern horizon.
August 19 – Asteroid 43 Ariadne at Opposition
Asteroid 43 Ariadne has my favorite name of all the named asteroids; it is named for the Greek heroine Ariadne who helped Theseus escape the Minotaur, became the wife of the god Dionysus, and is associated with mazes and labyrinths.
On the night of August 19th, 43 Ariadne will be at opposition and brightly lit. Ariadne is the second-largest in Flora asteroid family, and will be visible in the constellation Aquarius. Unfortunately, a bright (93%) illuminated moon might interfere with viewing prospects.
August 19 – Jupiter at Opposition
As mentioned previously about Saturn, it’s always a good night when one of the planets is at opposition. On the night of the 19th (in addition to trying to spot my favorite asteroid), you can also see big Jupiter at its brightest.
Jupiter will be in the constellation Capricornus and the moon will not interfere with your viewing prospects. To get a great view like the one above, grab your telescope or binoculars.
August 20 – Close Approach of the Moon & Saturn
Similar to the second close approach with Jupiter, the Moon will make a second close approach with Saturn on the night of August 20th. On this night, they’ll pass within 3°42′ of one another in the sky. This is too far apart to see through the view of a telescope or binoculars, but you can use the brightly 98% illuminated to hop to Saturn and its iconic rings.
August 21 – Close Approach of the Moon & Jupiter
Jupiter continues to follow Saturn through the sky (ever since the Great Conjunction last year) and thus has its own close approach and conjunction with the Moon on the night of August 21st.
For this close approach between the Moon and Jupiter will pass within 3°57′ of one another. This is not quite close enough to see with a single telescope or binocular view, but just like with Saturn, both the Moon and Jupiter will be bright and easy to spot.
August 24 – Asteroid 89 Julia at Opposition
For the third and final asteroid-viewing opportunity in the August night sky, 89 Julia will reach opposition as the month draws to a close. On that night, look for the brightly lit asteroid in the constellation Aquarius. While 89 Julia is a large main-belt asteroid, and thus somewhat easier to spot with a good telescope with a star-finder (or binoculars with a good night sky app), the Moon will also be 92% illuminated and may interfere depending on the time of night you’re out stargazing.
Do you have questions or comments about these August night sky events? Let me know in the comments.