Courtesy U.S. Naval Observatory
Watch for two bright star-like objects near the moon as darkness falls on June 18. These colorful gems are the sparkling blue-white star Spica and the golden planet Saturn. The chart at the top of this post shows Spica and Saturn as they appear in North America on June 18, 2013. But as darkness falls around the world tonight, look for these celestial beauties to pop out quite close to the waxing gibbous moon. If you have difficulty discerning the colors of Spica and Saturn, remember that binoculars help to highlight blue-white Spica and golden Saturn.
June 2013 guide to the five visible planets
As seen from North American latitudes at nightfall, Spica appears to the west (right) of the moon whereas Saturn appears to the moon’s east (left). But as viewed from Asia, Australia and New Zealand, the moon is seen to the west of Spica. From Europe, you’ll see the moon very close to Spica, and from Africa, the moon will actually occult -cover over – Spica at dusk and/or early evening. Click here to find out more about tonight’s lunar occulation of Spica.
To the human eye, Saturn does not appear as distinctly banded as the next planet inward, Jupiter. Yet, like Jupiter, Saturn is crossed by subtle bands, which are part of the planet's weather. Scientists speak of jet streams in Saturn's atmosphere and recently determined what causes them. Read more here. Image Credit: NASA/JPL/Space Science Institute
Mentally note the moon’s position relative to Spica and Saturn tonight, then check out the moon’s position at the same time tomorrow night. You’ll see that the moon has moved eastward relative to Spica and Saturn – or in the direction of sunrise. The moon moves full circle in front of the constellations of the Zodiac in about four weeks, but slow-plodding Saturn takes nearly 30 years to circle the Zodiac.
This is Saturn's largest moon, Titan, as seen by the Cassini spacecraft. When we gaze at the moon with the eye, we see only the upper layers of its dense atmosphere. But many mysteries lie beneath. Just today (June 28), scientists announced they are now almost certain that Titan has an underground ocean of liquid water. Read more here.
By the way, try looking at Saturn with a telescope, if you have one. Even a backyard telescope enables you to view Saturn’s glorious rings.
At present, Saturn’s rings are inclined our way at a little more than 17o from edge-on, near their minimal inclination for the year. However, the rings will begin to open up more widely, starting in September. By the end of this year, the tilt of the rings will have increased to 22o.
That’s this Tuesday night, June 18, 2013: The star Spica and the planet Saturn near the waxing gibbous moon.
