Clouds fly by the moon earlier this week in this 25-second time exposure. Jupiter is the bright "star" just above the tree. Details: 20mm lens, f/5 at ISO 200. Photo: Bob King
At least in the Duluth, Minnesota region, it’s been clear night after night, allowing us to watch the daily rising of the moon and its changing phase. Tonight the moon lines up for a wonderful conjunction with the planet Jupiter. Both are brilliant and eye-catching guaranteeing a splendid time for all. The pair will be up around 9:45 p.m. in the east, but if you wait until 10:30 or later, they’ll be easier to see after having cleared any treetops and buildings.
The waning gibbous moon and brilliant Jupiter will pair up tonight for a pretty sight. Maps created with Stellarium
If good fortune brings you clear skies, take out your binoculars and point them at any bright star, bring the star to a crisp focus and then aim them at Jupiter. If you’re using a magnification of 7x or higher (typical for binoculars) you should be able to see several of Jupiter’s brightest moons. You’ll need to hold them steady so the image doesn’t bounce around. I like to scrunch up against a wall for support but have been known to set the binoculars on the roof of my car, too. Whatever works for you. Once you’re focused in, look very close to the left or east of the planet and you should see several tiny “stars”. Tonight the moons Io and Ganymede will be very close together and so appear as a single “star” to your eye. You’ll need a small telescope to resolve them into two.
Try finding several of Jupiter's brightest moons in binoculars. Each number stands for a moon. IV is Callisto, II Europa, III Ganymede and I Io. Each is approximately the size of our own moon.
Each of Jupiter’s moons has its own period of revolution around the giant planet ranging from 1.8 days for innermost Io to 16.7 days for Callisto. That means they’re always on the move forming new arrangement every night you look. The map below depicts where they’ll be tonight, but if you’d like to know which is which on any given night, click on this Jupiter’s Moons utility to find out.
A friendly and relatively painless observing challenge would be to identify all four of the moons and even make sketches of their changing positions over a week’s time. Hey, wait a second – that’s exactly what Galileo did when he discovered them just over 400 years ago. He likened them to a solar system in miniature, a sight you can easily see for yourself by walking in the great Italian’s footsteps.
Would it have been Jupiter I saw on Friday early morning as I was heading to work out? It was extremely bright and just to the lower left of the moon.
Yes! That was Jupiter alright. It was neat to see them near one another for a couple nights in a row.