Welcome to the Night Sky Map for June 2020! Why do objects like stars appear move across the sky at night? The planets, too, move like clockwork through the sky. Take advantage of the pleasant June weather to watch the “Cosmic Clock” in action.
Just click here or on the image below to open the printable map—then bring outside!
Secrets of the Cosmic Clock
Objects in the sky always appear to be moving. The Sun and Moon rise in the east and set in the west. Less obviously, the stars and constellations also rise and set each day. Like clockwork, every celestial object marches across the sky from east to west and in 24 hours returns to its starting point.
The discovery that nearly all of this apparent motion is caused by Earth rotating on its axis is one of humankind’s greatest scientific achievements. Nowhere is this clocklike behavior more evident than in the northern sky. June is a lovely month, weatherwise, to watch the Cosmic Clock in the night sky. Just look up!
You’ll need a nice, dark location away from bright city lights. Wait until at least 11:30 P.M.; the June sky isn’t fully dark until then. Be prepared to stay up late and to devote at least 2 full hours to stargazing. Give your eyes at least 20 minutes to become adapted to the dark and then look due north to find Polaris, the North Star, less than halfway up the sky. It’s the only bright star in the area.
Polaris and the Little Dipper
Look above Polaris to follow a curving line of three dim stars until you reach a small starry rectangle. You’ve just traced the handle and bowl of the Little Dipper, which appears to be standing on end. Note how the bowl is located directly above Polaris. If you think of Polaris as the center of a clock face, then the bowl is pointing straight up, like the hour hand of a clock set to 12:00.
With the position of the Little Dipper firmly in mind—perhaps after making a simple sketch—spend the next hour or so enjoying the other celestial sights. We’ll get back to the Cosmic Clock shortly.
Greater Bear and Big Dipper
For now, look to left for the constellation Ursa Major, the Greater Bear, which appears to be standing on its nose in this view. The bear’s rump and tail are better known as the Big Dipper, but from a dark location you can make out its entire body, from its legs and paws to the tip of its nose.
Cassiopeia and Drago, the Dragon
To the right and near the horizon, look for the Big W shape of Cassiopeia, the Queen, and above her, King Cepheus, in the shape of a child’s sketch of a house. Above them both is the head of Draco, the Dragon, whose body winds in an S-shape that curves above the Little Dipper.
The Lyre and the Swan
Look to the right of Draco for the perfect little Parallelogram in the constellation Lyra, the Lyre. Below Lyra lies the (nearly) upside-down Northern Cross, whose stars comprise the body of Cygnus, the Swan.
The Cosmic Clock
Assuming that an hour has passed, go back to our starting point, the Little Dipper!
- Note how the whole constellation has rotated slightly counterclockwise around Polaris and is now in the position labeled “1.”
- Wait another hour, and the Little Dipper will have rotated further to position “2.”
This clocklike motion will continue throughout the night. The Sky Map shows the Little Dipper’s position for 4 consecutive hours.
Importantly, it’s not just the Little Dipper that appears to rotate around Polaris. The entire sky moves in the same circular path, with Polaris at its center.
This is all due to Earth’s rotation, which gives us our days, our nights, and our Cosmic Clock!
Click here or on map below to enlarge (PDF).
Sky map produced using Chris Marriott’s Skymap Pro
Note: How to Read the Sky Map
Our monthly sky map does not show the entire sky which would be almost impossible. Instead, the map focuses on a particular region of the sky each month where something interesting is happening. The legend on the map always tells you which direction you should facing, based on midnight viewing. For example, if the map legend says “Looking Southeast,” you should face southeast when using the map.
The map is accurate for any location at a so-called “mid northern” latitude. That includes anywhere in the 48 U.S. states, southern Canada, central and southern Europe, central Asia, and Japan. If you are located substantially north of these areas, objects on our map will appear lower in your sky, and some objects near the horizon will not be visible at all. If you are substantially south of these areas, everything on our map will appear higher in your sky.
The items labeled in green on the sky map are known as asterisms. These are distinctive star patterns that lie within constellations. When getting your bearings under the stars, it’s often easiest to spot an asterism and use it as a guide to finding the parent constellation.
The numbers along the white “Your Horizon” curve at the bottom of the map are compass points, shown on degrees. As you turn your head from side to side, you will be looking in the compass direction indicated by those numbers. The horizon line is curved in order to preserve the geometry of objects in the sky. If we made the horizon line straight, the geometry of objects in the sky would be distorted.
See more monthly highlights of the night sky in the June Sky Watch.