After the monsoon season is tapering out, temperatures rise again. Fortunately, we cannot control the weather, and we desperately need rain in Southern Utah. We get bummed about not being able to do tours during those challenging weeks, but we will always do our best to accommodate you during your travels to Zion.
During the last tour in August, we had a balmy 80 degrees Fahrenheit at the field with guests in t-shirts and shorts. We always recommend layering up, though. Bring that extra jacket! By the way, we get many international visitors, and an easy way to convert Fahrenheit into Celsius is to subtract 32 from Fahrenheit and divide by 2 (the real divide is 9/5, but the math with 2 is easier and close enough). That'll give you 24 degrees Celsius, which is close enough to the actual 26.6 Celsius number.
Night Sky around 10 PM on September 15. Source: Stellarium
The Summer Triangle with Vega/Deneb/Altair continues to move past the meridian quickly in the early evenings, indicating that summer is in its last throes. The spring triangle has all but disappeared in the West together with the setting Sun. Autumnal Equinox will be on September 22 in the Northern Hemisphere with equal day and night. Fall does not have a celestial triangle to herald the changing of the leaves colors, but many astronomers use the Great Square in Pegasus as a seasonal marker. It's called the Fall Square and indicates the body of the winged horse in Greek mythology on which Perseus galloped to rescue Andromeda from the sea monster Cetus. Those figures of the "Clash of the Titans" continue to rise in the East. There are two movie versions available to watch to brush up on your Greek mythology: a 1981 version and a 2010 version.
The Andromeda constellation hosts the Andromeda Galaxy, or Messier 31, our closest galactic neighbor. It is the farthest object seen with the naked eye and about 2.5 million light years away. That means the light left Andromeda 2.5 million years ago. The Andromeda is about five times bigger than our Milky Way and hosts about 1 Trillion stars! That is a 1 with twelve zeroes. It is best observed on a moonless night with averted vision, and here you can see its approximate location:
Location of the Andromeda Galaxy. Source: Stellarium
Find the "W" of Queen Cassiopeia and use the top triangle to point towards the constellation Andromeda, about 15 degrees away, which is a little more than the width of your fist at the outstretched arm. Coming from the belt of Princess Andromeda, you connect the stars of the belt and point up. A little to the right of the last star is a fuzzy patch. Congratulations! You found the Andromeda Galaxy!
Look below to understand the makeup of the human eye and the benefit of averted vision (looking at something out of the corner of your eye). At the retina's center, cones help us see during the day. On the outside ring are rods that help us see at night. So, by looking a little to the side of the faint object you want to observe, the rods become more active, and you can see that object a little better.
The human eye. Source: BBC Sky at Night
Saturn is a delight for our guests. The rings are beautiful, and we know that the guest sees Saturn when they proclaim, "Ohhhhhh!" or "Wow!". Seeing an image through the eyepiece takes a bit of practice, but we are always patient until we get that exuberant outburst! But Jupiter is no slouch, either! It will be at opposition, at its brightest in the middle of September, and you can't miss it when it is rising in the East! Even with binoculars, you can see the four Galilean Moons: Calisto, Ganymede, Io, and Europa. They are lined up like pearls on a string around the equator of the largest planet in our Solar System. All the planets fit into it about 2.5 times with room to spare. Europa is one of the most promising locations for life outside Earth in our Solar System. The Juno mission has captured fantastic images of Jupiter. If you want to educate yourself: Juno Mission.
Jupiter and the four Galilean Moons. Source: Stellarium
Astronomical Dates and Times:
First Quarter: September 3
Full Moon: September 10 (Harvest Moon, Corn Moon)
Last Quarter: September 17
New Moon: September 25
Astro Twilight End September 1 (Virgin, UT): 9:32 PM
Astro Twilight End September 15: 9:08 PM
Astro Twilight End September 30: 8:44 PM
Meteor Showers: None