One Sky Week is a community astronomy and environmental-awareness event organised in Big Bear Valley, California, in support of dark-sky conservation.
The event encourages residents and visitors to explore the beauty of the night sky while learning about the importance of protecting natural darkness from artificial light pollution.
The week includes guided night hikes, telescope stargazing sessions, astronomy presentations and educational content about the relationship between dark skies, wildlife, forest ecosystems and human health.
The event is organised in connection with DarkSky International’s annual global Under One Sky conference. The conference brings together an international community of astronomers, conservation advocates, educators and people interested in protecting the nighttime environment.
The 2026 theme for the global conference is “Night in Balance,” focusing on light pollution, satellite proliferation and emerging challenges affecting the natural night sky.
The programme aims to encourage responsible outdoor lighting, promote astronomy education and strengthen local participation in night-sky conservation.
| Activity | Address |
| Night hike starting point – Snow Summit | 880 Summit Boulevard, Big Bear Lake, CA 92315 |
| Night hike trail | Towne Trail, Big Bear Valley |
| Telescope stargazing – November 7 | Erwin Ranch Park, 1140 Hatchery Drive, Big Bear City, CA |
| Bat Nights – Discovery Center | 40971 North Shore Drive, Fawnskin, CA 92333 |
Night hikes
| Date | Time | Price |
| November 4 | 8:00 PM–9:30 PM | $15 per person |
| November 6 | 8:00 PM–9:30 PM | $30 per person |
| November 7 | 8:00 PM–9:30 PM | $30 per person |
Participants should arrive at Snow Summit by 7:45 PM. The guided hike follows a mostly flat trail of approximately 1.2 miles, with a night-sky presentation and telescope stargazing. Shuttle transportation is provided back to Snow Summit.