In collaboration with Kanab’s future Stellar Vista Observatory and Pipe Spring National Monument, the Kanab City Library is hosting a Star Party in their parking lot on Monday, July 29, from 8 to 10 p.m., and beyond! Learn about the stars, planets and constellations in the summer sky, and how your family can help preserve the visibility of the Milky Way over Kanab with smart outdoor lighting choices. The event will celebrate a wonderful summer of reading for children and adults, and feature indoor presentations by Pipe Spring National Monument, as well as the Stellar Vista Observatory. There will also be a discussion of telescope design and use by Stephen Howells.

After 9 p.m., when twilight descends, the event will move outdoors into the library parking area, which will be roped off for the safety of the sky-watchers. There, a half-dozen or more astronomical telescopes will be set up to offer Kanab residents and visitors a first-hand look at stars, planets and deep sky objects, including star clusters and nebulae. Children must be accompanied by a parent in order to look through the telescopes. If skies are clear, this free event is guaranteed to inspire young and old alike!

Sunset will occur at 8:39 p.m. while civil twilight ends at 9:08 p.m., and astronomical twilight ends at 10:22 p.m., when the sky will be fully dark. Library parking lot lighting will be turned off and the City of Kanab has been asked to turn off pole-mounted lights at the pump track and basketball court in the Jacob Hamblin Park extension.

So, what’s the difference between civil and astronomical twilight?

The time between day and night when it is light outside but the Sun is below the horizon is known as twilight. Civil twilight is a scientific term defined as the period after sunset or before sunrise ending or beginning when the sun is about six degrees below the horizon and during which on clear days there is enough light for ordinary outdoor activities.

Astronomical twilight is the term used to describe the time, when our Sun moves within the range between 12 and 18 degrees below the horizon. During this time a glow still persists well after sunset, but begins to diminish rapidly.

During civil twilight, only very bright celestial objects can be observed by the naked eye. At this time of year, luminous night sky objects visible in civil twilight might include the Moon, Jupiter, the largest planet in our solar system, and a few super bright stars such as the red giant Antares, located in the constellation Scorpius, 700 times the mass of our Sun and 520 light years from Earth! As civil transitions to astronomical twilight, more stars and constellations appear.

When astronomical twilight ends and the sky becomes fully dark, distant and elusive deep sky objects become visible if you are in an area with little or no light pollution or direct ambient light from buildings. The human eye can take as long as 15 to 20 minutes to become fully dark adapted.

The best time for viewing stars, constellations and deep sky objects such as clusters, distant galaxies and nebulae, is after astronomical twilight ends in evening, or early morning before astronomical twilight begins when the night sky is totally unaffected by the light of our Sun.

On July 29, the moon will set early at 6:45 p.m., and the sky should be quite dark. Bring small flashlights for your safety while moving about the telescopes, but cover your flashlight with red cloth so white light does not impede the night vision of other participants. If you have a red flashlight, that’s the ideal color of light to use when stargazing.

The Stellar Vista Observatory is a resident-led nonprofit organization dedicated to the creation and operation of a public, educational space observatory for the enjoyment of residents and visitors to Kanab. Please friend us on Facebook at Stellar Vista Observatory!