Saturn at Opposition - Visible All Summer!

The beautiful ringed planet Saturn will be at opposition this coming Friday, May 22. It will be at its closest and brightest for the year. Just look to the east after sunset for a bright star-like object, low on the horizon. That's Saturn! See image below. 

Click on image to enlarge. Saturn rises at sundown on May 22, but will not be easily visible until 9 PM. Image Credit: Stellarium and Me

Saturn rises at sundown, reaches its highest point around midnight, and sets at sunup on May 22.

Saturn appears between the claws of Scorpius right now. It will reach its highest point around midnight, pictured here. Image Credit: Stellarium and Me

What does it mean when a planet is at opposition?  Astronomers say that a planet is at opposition when it is opposite of the Sun in our sky, and so rises in the east at sunset. It is easier to imagine this if you consider the geometry of the Solar System. Right now, Earth is passing in between the Sun and Saturn - Earth is lapping Saturn as the planets orbit the Sun. 

Earth orbits the Sun in 365 days. Saturn takes almost 30 Earth-years to complete an orbit! When Earth laps Saturn and the two planets make a line with the Sun, as they will on May 22, the two planets are at their closest points, and Saturn rises at sundown. Image Credit: SolarSystemScope.com

Notice that the Sun, Earth, and Saturn make a straight line on May 22. Also notice that Mars is almost on the opposite side of the Sun as Earth - it is nearly impossible to see any longer because it is covered by the Sun's light. Jupiter and Venus are bright, and visible for several hours after sunset. Image Credit:
SolarSystemScope.com

Saturn's opposition only lasts one night, but the planet will be visible all summer. Venus and Jupiter are also visible right now - in fact they are so bright they are hard to miss! Venus appears as a super bright star-like object in the west as soon as the Sun sets. Jupiter is also visible at twilight, higher in the sky in the southwest.

Venus and Jupiter visible in the west as soon as the Sun sets. Image Credit: Stellarium and Me

You can see Saturn's rings if you visit Northmoor Observatory this summer, or if you have a steady hand and a good pair of binoculars. The Cassini spacecraft has been orbiting Saturn for over a decade now, taking amazing images of the gas giant and its moons. Click here to read a post all about the Cassini mission and see lots of images. The latest Cassini image is below:

Janus Stands Alone. Saturn's moon Janus (only 111 miles across) is silhouetted against the blackness of space, 1.6 million miles away. Saturn's rings are peaking out of the corner. Image Credit: NASA/JPL-Caltech/Space Science Institute

Learn more about the planets and what you can see in the night sky by visiting the Peoria Riverfront Museum's Dome Planetarium! Or join us for Pub Night Under the Stars, this Friday May 22, from 7-9 PM. Get tickets by calling 309-686-7000.