A NOTE ABOUT LATITUDE: These sky charts assume an observer at 40 degrees north latitude; much of the world's population lives within 20 degrees or so of 40 degrees north, so it is a useful latitude assumption. However, if you are north of this latitude, the stars will all appear shifted towards the south; if you reside south of this latitude, the stars will appear shifted to the north.
In the Northern Hemisphere during the summer, the sky does not really get dark until quite late, but we can still find a familiar shape in the sky towards the northwest. Within the constellation Ursa Major are seven stars of 2-nd magnitude, which are visible from all but the very worst light polluted areas. These seven stars are are an “asterism” - or shape that is recognizable but not a true constellation - known as the “Big Dipper” in North America, and “The Plough” in the U.K. From this asterism, we can find quite a few other constellations and bright stars. Let's begin with the “bowl” of the Dipper. First, watch this video (COMING SOON) on how to measure distance in the sky. And if you are unsure about the differences in magnitude, check out this video (COMING SOON) first as well.
The two end stars of the bowl are Merak and Dubhe. If we draw a line from Merak through Dubhe, and continue on slightly more than 25 degrees, we arrive at another 2-nd magnitude star: Polaris, also known as the North star. As the Earth spins on it's axis, Polaris hardly moves, as it is less than one degree from the north celestial pole, the spot in the sky around which the stars appear to rotate. Polaris is the end of the tail of “Ursa Minor” - the little bear, though many in North America refer to this as the “Little Dipper.” The “handle” or “tail” of this shape may be hard to see, but if you know that these stars curve back towards the Big Dipper, you should be able to find a slightly orange looking star of similar magnitude, about 15 degrees away from Polaris. This star is Kocab, and forms the end “lip” of the Little Dipper's “bowl.”
But back to the Big Dipper, this time, the arcing handle of the dipper shape. One easily remembered mnemonic is “Arc to Arcturus, speed on to Spica.” So if we track that curving line of three handle stars, then continue on 30 degrees, we find a brighter first magnitude star there, and that is Arcturus, the brightest star in Bootes, the Herdsman. Bootes forms an “ice cream cone” shape in the sky, though many of its stars are much dimmer than Arcturus. But don't stop there yet – we still need to “speed on to Spica!” Continuing our “arc” another 30 degrees past Arcturus, you will arrive at another bright star about the same magnitude as Arcturus, but this bluish looking star is Spica. This star anchors the quite dim constellation of Virgo, but there are many galaxies nearby which are great to target, so knowing Spica's location is helpful. Also, Spica is very nearly on the line of the ecliptic, so the planets will pass by this star from time to time as well.
Rising in the eastern sky are three first magnitude stars, in a rather wide triangle shape. Highest up is the brightest of these stars, which is Vega of Lyra the Harp – a small, somewhat dim constellation that has some nice binocular double stars and the well-known Ring Nebula. Towards the south and somewhat dimmer, but still 1-st magnitude, is Altair, at the nose of Aquila the Eagle. And completing the triangle is the dimmest star of the three, Deneb of Cygnus the Swan. It will be north of Altair and east of Vega. Our Milky Way galaxy courses through this triangular area of sky, so even a cursory glance of this area with binoculars will reveal many more stars.
The distance from Deneb to Altair is approximately 40 degrees. If we extend another 40 degrees beyond Altair, we will run into an asterism within Sagittarius known as “The Teapot.” This is a wonderful area of sky containing many bright globular clusters and several bright nebula. Look for the “spout of the teapot” - just above this, where “steam” should be coming from the spout – this is looking directly towards the center of our Milky Way galaxy. Looking to the right of the “Teapot” towards the south, there is really only one first magnitude star in this part of the sky, and that is the red giant star Antares of Scorpius.
If we draw a line from Antares back towards Vega overhead, there is a very large constellation here, Ophiuchus the serpent bearer; some of it's 2-nd magnitude stars should be visible, which may help you spot the globular clusters within it's borders. Heading back up to Vega then turning towards Arcturus, we find Hercules the strongman, though with mostly dim stars, this can be challenging to see from light polluted areas, though it contains some of the finest globular clusters in the summer sky. To the east, there are autumm constellations and stars rising that may be visible, such as Pegasus, Andromeda and Almaak, among others. Click ahead to see the Autumn Constellations page, as these constellations will be visible later at night during the summer months.
That's a great primer course on how to find your way around the summer sky – give it a try on a clear night, and if you want to see more, look for the star charts at this site for deep sky objects you may be able to spot in the summer sky as well.