Aug 19

Sky Report: August 21 – 27

Saturn had the same orientation (rings tilted 9° from our line of sight) as this year when the Hubble Space Telescope photographed it in 2011. Raw data courtesy NASA STScI, processed image © Ted Stryk.

You might see relatively faint Mars only a few degrees above the west horizon a half-hour after sunset, but eyes will be upon the other planet in the early evening sky – Saturn. Saturn is low in the east-southeast as the sky grows dark, but it’s well-up in the southeast later in the evening.

To see it properly through a telescope, however, you must wait at least an hour and actually two for it to rise above the densest and most turbulent layers of our atmosphere, so the image looks sharp and clear. I once looked at Saturn immediately after it rose through a 40-inch refractor (not a typo) and it was so blurry I could barely make out the rings. Last year I saw it through a 24-inch refractor on a night of average seeing and it looked no better than through my 5-inch refractor on a night of excellent seeing. In a month it will already be high enough to enjoy through a telescope at sunset, so be patient.

On the 27th Saturn is at “opposition”, meaning it’s opposite the sun, rising at sunset and setting at sunrise. This is also when it is closest to earth, 814 million miles distant. Some news media will sensationalize the 27th by advising you to look at it on that night when it’s at its biggest and brightest, but that’s hype because its distance, brightness, and size change only negligibly through the year. The planet itself spans 19” (arcseconds) and the rings 43”, where 1” is a 60th of a 60th of 1°. You need a telescope that magnifies at least 40x to barely see the rings.

Bright Jupiter rises 3 hours after sunset.

What would be really interesting to watch if it happened a bit later is the occultation of Antares by the moon on the 24th. An “occultation” is when one thing hides, or occults, another, and in this case the moon hides the bright star Antares by moving in front of, and covering, it. Unfortunately for us in the western states this happens shortly before sunset, while the sky is still brightly lit, so it will be a trick to see Antares, although you might with binoculars and should with any telescope. The occultation begins at 7:52 as seen from Kanab (and at a similar time within hundreds of miles), so use your binoculars and look immediately to the lower left of the moon a little before 7:52 and watch the moon approach and then cover Antares. It’s the dark side of the moon that does the deed, so Antares will abruptly disappear.

The moon continues in its orbit and uncovers Antares an hour later, at 8:56 in Kanab. Now it’s dark. Antares reappears from behind the lit side of the moon so it will reappear gradually as it separates itself from the moon’s bright edge. As is so often the case, binoculars will greatly enhance the view.

Antares is one of four bright stars that the moon can occult, the others being Regulus, Spica, and Aldebaran.

Stellar Vista Observatory provides portable telescopes and tripod mounted binocular kits on loan for free to residents and visitors in Kane County. Enhance your enjoyment of the night sky! To learn more, request a loan, or attend one of SVO’s free public star parties for 2023, visit or drop in to the Kane County Office of Tourism.

About the Author:

John Mosley was Program Supervisor of the Griffith Observatory in Los Angeles for 27 years and is the author of “Stargazing for Beginners” and “Stargazing with Binoculars and Telescopes”. He and his wife live in St. George where he continues to stargaze from his retirement home while serving on the advisory committee for Stellar Vista Observatory.

Comments are closed.