Stargazing is typically a relaxing evening pursuit at the conclusion of a busy day. But the stars and planets can’t tell time, and they sometimes put on their best displays in the hours just before sunrise. So it is in mid-May, when the Moon dances with our two largest planets in the predawn sky.
Just click here or on the image below to open the printable map—then bring outside!
The planets, of course, are Jupiter and Saturn, the largest and second largest planets in our solar system. Over the course of four mornings, from May 20 to May 23, the Moon moves steadily from right to left past the two planets. During this time, Jupiter and Saturn will barely change their positions at all. In contrast, the Moon will be in a different location each morning, and her shape will also change every day.
First of all, you’ll want to set your alarm for no later than 30 minutes before sunrise each morning; 45 is even better. To find your sunrise time, use the Almanac’s Sunrise and Sunset Calculator. The closer to sunrise you awake, the more washed out and less impressive the view will be, so don’t press “Snooze” on your alarm!
On May 20, the Moon is just to the right of Jupiter, the King of Planets. Less than 2 days past full, the Moon still looks nice and round. To the lower right of the Moon is the bright star Antares. As with so many things in astronomy, the term “bright” is relative. Although mighty Antares is the 15th brightest of all stars, it’s also more than 7 million times farther from us than Jupiter. So, from our point of view, Jupiter appears brighter than Antares. NASA’s Juno spacecraft is currently orbiting Jupiter and sending back science data and spectacular images.
The next morning, May 21, finds the Moon hovering above the “spout” of the Teapot asterism. The Teapot is composed of the brightest stars in the constellation Sagittarius, the Archer. When you gaze toward Sagittarius, you’re looking toward the center of our galaxy, the Milky Way. Note that the Moon no longer looks round. She’s becoming smaller, or waning, and has assumed her gibbous phase—less than full but still greater than quarter.
A day later, on the morning of May 22, the Moon is approaching Saturn, the Ringed Planet, and sits near the Teapot’s handle. More obviously gibbous now, the Moon is shaped something like a lopsided egg.
It’s now May 23, the last morning of our Moon’s close encounter with Jupiter and Saturn. Overnight, the gibbous Moon has moved from one side of Saturn to the other.
Saturn is a spectacular planet. In 1610, Galileo Galilei used one of his early telescopes to observe Saturn and came away puzzled. The modest resolution of his tiny instrument prevented Galileo from recognizing the rings for what they were. Instead, he thought that Saturn resembled a planet with a smaller planet on either side. A few years later, he described Saturn as having “ears” or “handles.” It wasn’t until 1655 that Dutch astronomer Christiaan Huygens correctly asserted that Saturn was surrounded by a ring
Until Next Time…
Our 4-day Moon dance is over. Jupiter and Saturn will move only slowly from their current positions, but the Moon will continue flying farther to the left every day. She’ll continue shrinking, too, until becoming a New Moon (and therefore not visible) on June 3.
May 2019 Sky Map
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 sky map does not show the entire sky which would be almost impossible. Instead, the monthly map focuses on a particular region of the sky where something interesting is happening that month. 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.