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Old 04-09-2017, 03:35 PM
Terri Finch's Avatar
Terri Finch Terri Finch is offline
Event Manager
Join Date: May 2008
Location: Phoenix AZ
Posts: 2,745
Default Nearby Bortle Site Readings

Here are some sites PAS utilize and their Bortle readings.
This info is provided to the Members by President Sam Insana.

By President Sam Insana

The darkness of the night sky can be measured in Bortle Units. In February 2001, John
Bortle published his famous scale in Sky and Telescope Magazine.
Bortle 1 is the darkest sky possible
Bortle 5 is where the Milky Way is faintly visible to the naked eye.
Bortle 9 is very bright inner city skies with only a few very bright stars visible.
PAS has taken Bortle readings using a Sky Quality Meter about 2 hours after sunset with
no moon or clouds present at various locations. This can help you find a dark sky site
near you. The lower the Bortle number, the darker the skies and the more objects can be
seen. A 6 or 8 inch diameter telescope at a Bortle 1 or 2 site can look as good as a 16 or
18 inch scope at a Bortle 5 or 6 site.
Bortle 1.0 18 miles south of Jacobs Lake, 22 miles north of north rim of Grand Canyon
Bortle 1.5 Kaibab lodge 18 miles north of north rim of Grand Canyon
Borlte 1.9 Moran Point South Rim of Grand Canyon
Bortle 2.0 Eastern limits of Munds Park about 20 miles south of Flagstaff
Bortle 2.0 Antenna’s air field about 98 miles west of Central Phoenix N of I-10
Bortle 2.0 Hovatter Rd Antenna’s site about 100 miles west of Central Phoenix
Bortle 2.5 Cherry Road about 70 miles north of Phoenix
Bortle 2.6 Arcosanti about 60 miles north of Phoenix
Borlte 2.7 Chris Johnson’s Cutting Horse Ranch near Mayer, Az
Bortle 3.4 Pickett Post trailhead about 60 miles SE of Phx off Highway 60
Bortle 4.0 Buffalo Park in N Flagstaff
Bortle 4.2 Town of Tusayan 5 miles south of Grand Canyon
Bortle 4.3 Cowtrack Ranch in Carefree
Borlte 4.3 Spur Cross Ranch Park Cave Creek
Bortle 4.3 New River
Bortle 4.3 Robbins Butte East of Buckeye 40 miles SW of Phoenix
Bortle 5.0 Paradise Valley Community College Black Mountain Campus North Valley
Bortle 6.6 Desert Botanical Gardens Phoenix
Bortle 7.2 Roadrunner Park NE Phoenix
Terri Finch, PAS Events Manager since 2008 We are All Star Stuff !!!
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