Night Sky Highlights for July-September 2022
Solar System
Perseid Meteor Shower
Peaking on the night of August 11-12
This is not a good year for the Perseids, because the full Moon coincides with the peak of this annual shower. The bright Moon will substantially reduce the number of meteors that can be seen. On the positive side, many Perseids are bright enough to be seen even in the moonlight. Remember that the shower extends for several days on both sides of the peak night.
Mercury
The best chance to see Mercury this summer will be in late August, when it will be above the western horizon after sunset. Its greatest eastern elongation, when it is farthest from the Sun, will be on August 27.
Venus
Early risers can see Venus in the eastern sky before dawn all summer long. Even though it is on the far side of the Sun from our viewpoint, Venus will still be strikingly bright at about magnitude -3.9. Through a telescope, its 10″ disk will appear nearly round.
Mars
The red planet can be seen in the southeastern sky before dawn during the first part of the summer. By mid-September, it rises in the east around midnight. Through a telescope, its disk will grow from about 8″ in early summer to about 11″ in late summer as it gradually gets closer. This time around, its closest approach to Earth will be in December 2022.
Jupiter
Jupiter is in the constellation Pisces. In July, it will rise around midnight and be visible for the rest of the night. By early August it rises around 10pm and in early September it rises around 8pm.
Saturn
The ringed planet is in Capricornus this year. In July, it will rise in the late evening and be well placed for observing by about midnight. As the summer progresses Saturn rises earlier, reaching opposition (rising as the Sun sets) on August 14. In September and into the fall, it can be viewed as soon as the evening sky gets dark.
Uranus
Uranus is in Aries, which means that to observe it this summer you will have to wait until the early morning hours (in early summer) or the late evening (in late summer). To find either Uranus or Neptune, you will need a go-to scope or a finder chart such as the one in this article from the Sky & Telescope website:
www.skyandtelescope.com/observing/planets/ice-giants-neptune-and-uranus/
Neptune
Throughout 2022 Neptune is in Aquarius, roughly 10 degrees to the west of Jupiter and rising slightly ahead of it. Though a telescope it has a greenish or bluish tint which helps to distinguish it from any nearby stars. High magnification (150x or more) will show its small disk.
Deep Sky Objects
The sky on a summer evening is full of so many deep-sky wonders that some good targets can get neglected. The objects below are not as well known as the typical star-party favorites, but they are well worth observing. The links provide star-hop charts for finding each of these objects.
Messier 18
Open cluster in Sagittarius
Messier 18 is a small open cluster of a few dozen stars with an overall magnitude of 7.5. It is flanked by Messier 17 (the Swan Nebula) to the north and the Messier 24 star cloud to the south. The cluster is about 4,900 lights years away. Star-hop chart
Messier 19
Globular cluster in Ophiuchus
This is an unusual globular cluster because it appears oblong in the north-south direction, whereas most globulars appear round. It is about 29,000 light years away, and just about 6,500 light years from the center of our Milky Way galaxy. Star-hop chart
Messier 62
Globular cluster in Ophiuchus
Located about 4 degrees to the south of Messier 19, Messier 62 is similar in size and brightness (both about magnitude 7.2). These two globulars will appear as fuzzy balls in small telescopes or binoculars, but with medium to large scopes some of the individual stars can be resolved. Star-hop chart
Messier 107
Globular cluster in Ophiuchus
Here is another one of the many globular clusters in Ophiuchus. It is a little smaller and dimmer (magnitude 8) than M19 and M62, but it is still easy to see in just about any telescope. The cluster is about 21,000 light years away. Star-hop chart
NGC 6934 (Caldwell 47)
Globular cluster in Delphinus
This fourth and last globular cluster on our list is the dimmest (about magnitude 8.9), and it appears quite small and faint through amateur telescopes. It is also much farther away, about 51,000 light years. Star-hop chart
NGC 6939
Open cluster in Cepheus
This cluster is just 2/3 degree to the northwest of the galaxy NGC 6946 (see below), and the two make an interesting visual contrast both in astrophotos and through a wide-field eyepiece. The cluster contains about 70 stars spread over a diameter of about 10 arcminutes, and it is about 5,900 light years away. Star-hop chart
NGC 6946 (Caldwell 12), the Fireworks Galaxy
Spiral galaxy in Cepheus
At about magnitude 9, this face-on spiral galaxy is dimmer and harder to spot than the cluster NGC 6939, but with a medium-sized telescope both will be seen in the same field of view in a low-power eyepiece. The galaxy is about 25 million light years away, about 4000 times farther away than the open cluster. Star-hop chart
NGC 7243 (Caldwell 16)
Open cluster in Lacerta
The 16th entry on the Caldwell list is a coarse open cluster of about 70 stars spread over an area about two-thirds the diameter of the Moon. It is about magnitude 6.4 and can be spotted with binoculars. With a telescope, use a low-power eyepiece for the best view. Star-hop chart
Collinder 399, the Coathanger
Open cluster in Vulpecula
This cluster consists of about 10 bright stars arranged in the shape of a coathanger, (plus some dimmer ones). It stretches across about one degree of sky, and it is not hard to spot with the naked eye as a hazy patch. It is a good target for binoculars or a small telescope. Star-hop chart
Kappa Bootis
Double star in Bootes
The two components of this attractive double star are magnitudes 4.5 and 6.6. Separated by 13.4 arcseconds, they can be resolved with even a small telescope. The pair is about 155 light years away. Star-hop chart
T Lyrae
Carbon star in Lyra
Carbon stars have an abundance of carbon in their atmospheres which gives them a very red color. The deep red color of T Lyrae when seen through the eyepiece is really very striking. The star is just about 2 degrees to the southwest of Vega. It is over 200 times brighter than our Sun. Star-hop chart