Alton.
The definitive guide to dark skies and celestial observation in Alton, IL. Verified using National Park Service and NASA Night Sky Network Clubs data.
Quick Guide for Alton
- Top Community Pick: McDonnell Planetarium - Forest Park (~19.2 miles)
- Best Scientific Reading: Bortle 6.0 at Log Cabins
- Local Experts: Southern Illinois University Edwardsville Star Parties
- Verified Observations: 5 distinct spots
If you’re looking to escape the light pollution of Alton, you’re in luck. While enthusiasts often gather at McDonnell Planetarium - Forest Park for its accessibility, scientific audits conducted by the National Park Service at Log Cabins provide the most accurate reading of the regional sky quality, measuring at a Bortle 6.0. The local landscape of Alton offers several pockets of darkness that are perfect for deep-sky observation.
The Best Times for Stargazing in Alton
Since Alton sits in a transitional light zone, viewing is best during the New Moon or after midnight when some commercial lighting is reduced.
Expert Tips for Alton Observers
When visiting McDonnell Planetarium - Forest Park, remember to check if the gates close at sunset or if a night-use permit is required. Binoculars are a favorite for regulars this location for sweeping views of the Moon’s craters and larger constellations. Local enthusiasts often frequent this spot, making it a great place to meet experienced observers. Regardless of your gear, allow 30 minutes for your eyes to fully dark-adapt.
Illinois Guide
Local Top Spots
Community-vetted locations known for clear horizons and accessibility for telescopes and astrophotography.
McDonnell Planetarium - Forest Park
" 'SLSC Solar Public Telescope Viewing at McDonnell Planetarium, weather permitting, the St Louis Astronomical Society and the Science Center will set up telescopes outdoors to view the Sun and be on-hand to answer your questions. The telescopes will be set up right outside the McDonnell Planetarium building. "
Tower Grove Park - Stone Shelter
" {'Due to excessive cloud cover and rain potential forecasted for tomorrow night, we will have to cancel this event. "
Gateway Arch
" There will be free telescope viewing provided by volunteers from the St. Call 314-655-1704 that evening for an update if you aren't sure about the weather., 'Check out the stars on the Gateway Arch Entrance Plaza! "
Stacy Park
" {'Star-B- is for SLAS members and their guests only.'} "
Louis Latzer Library [Outreach Only]
" His presentation is highlighted by photos, and capped with video of the 2017 total solar eclipse. The talk will be followed by telescope viewing outdoors, weather permitting.' "
NPS Sky Measurements
Instrumented readings from the National Park Service Night Sky Program, providing the most accurate SQM and Bortle classifications.
Log Cabins
Fort Donelson NB
"SQM of 20.47 at 2035 local time. Only fair transparency and seeing. Some fast moving clouds. High humidity. Milky Way visible from 20 degrees above north horizon. Great rift visible, Saggitarius cloud not easily visible, Scutum cloud not visible. Milky Way about 10-12 degrees wide, but faint and no fine details. To the NW a blue white light dome easily seen. Due East is the Clarksville lightdome almost 25 degrees high and 15 degrees wide. Core is bright. Adjacent to the light dome is a spotlight (which we determined was coming from the cemetary here in FODO park). To the West and Southwest is another lightdome fainter than Clarksville, but brighter than the Milky Way"
Houchin's Field
Mammoth Cave NP
"A very calm, humid and clear night. Dewfall occurred during data collection, however dew heater prevented lens fog. Multiple light domes evident from site, as well as a continuous glow along horizon in all directions. Airglow was present. Andromeda galaxy easily visible, Beehive (Pegasus) visible with medium effort. Prominent dust lanes in Milky Way visible at zenith, but not below ~50 degrees. Limiting magnitude found in Pegasus."
International Dark Sky Parks
Premier locations certified for their exceptional dark sky quality and commitment to light pollution mitigation.
Stacy Park
Stacy Park is a 35-acre park located in Olivette, Missouri and is approximately 10 miles west of St. Louis City. Established in 1926, Stacy Park is one of five…
Middle Fork River Forest Preserve
Middle Fork River Forest Preserve is a 688-hectare site in Champaign County, Illinois, U.S. It is one of six public preserves owned and operated by the…
Local Astronomy Clubs
Connect with experts and fellow enthusiasts through local astronomical societies and community groups.