NSF NOIRLab Celebrates International Dark Sky Week 2025

From 21 to 28 April you can discover and protect the night sky by participating in citizen science, virtual events, pledges, and more

21 April 2025

International Dark Sky Week (IDSW) is taking place from 21 to 28 April 2025. This week serves as both an annual celebration of the beauty and significance of Earth’s night sky, and a major push for its preservation. This announcement highlights the many ways that you can get involved!

During this Dark Sky Week, NSF NOIRLab, funded by the U.S. National Science Foundation, and co-sponsor DarkSky International encourage you to get involved with their international citizen-science program, Globe at Night. This program invites everybody to contribute to dark sky protection by submitting night sky brightness measurements to a global database in a simple and accessible way. Since launching 19 years ago, Globe at Night has collected over 200,000 citizen-submitted data points. This robust dataset is serving as an invaluable resource to scientists studying the effects of light pollution on Earth.

Light pollution is the excessive use of man-made lighting that reduces the darkness of the night sky. The increase in light pollution in society has prevented entire generations of humans living in urban and suburban areas from seeing the Milky Way overhead, a sight once accessible everywhere on Earth. While light pollution obscures the view of stars, planets, and countless other cosmic features from both eyes and telescopes, it is not just a hindrance solely to astronomers. Light pollution negatively affects human circadian rhythms and biological systems important to our health and well-being. It also harms various ecological and biological systems such as nocturnal animals and insects.

To participate in Globe at Night’s April Campaign, simply view the night sky over your home to find the constellation Leo in the northern hemisphere, or Canis Major and Crux in the southern hemisphere. Then, log your observation by visiting the Globe at Night Report page on a web browser on your smartphone or computer. You will match your local view of the constellation with star charts varying in light pollution effects, indicating the night sky’s brightness in your area. 

Your opportunities to participate in dark sky protection and light pollution mitigation do not end there. DarkSky International is also offering several resources to make use of during Dark Sky Week and beyond. They are hosting a variety of virtual events and sessions this week, collecting pledges to protect the night sky, and assisting communities in requesting official proclamations to raise awareness about light pollution.

Additionally, the International Astronomical Union (IAU) Office for Astronomy Outreach (OAO) will be hosting a panel discussion on light pollution policy on 24 April at 2:00 p.m. UTC. The panel is titled ‘Protecting Our Dark Skies — Involving Policy Makers in the Defence of the Night Sky’ and will be streamed live on the IAU OAO YouTube channel. This event, organised by IAU OAO in collaboration with DarkSky International, will bring together experts from public policy, astronomy, and environmental fields to address the urgent need to safeguard our night skies from light pollution. Tune into the engaging discussion here.

Missed out on stargazing this Dark Sky Week? Visit the Globe at Night webpage to see upcoming campaigns.

More information 

NSF NOIRLab, the U.S. National Science Foundation center for ground-based optical-infrared astronomy, operates the International Gemini Observatory (a facility of NSF, NRC–Canada, ANID–Chile, MCTIC–Brazil, MINCyT–Argentina, and KASI–Republic of Korea), NSF Kitt Peak National Observatory (KPNO), NSF Cerro Tololo Inter-American Observatory (CTIO), the Community Science and Data Center (CSDC), and NSF–DOE Vera C. Rubin Observatory (in cooperation with DOE’s SLAC National Accelerator Laboratory). It is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with NSF and is headquartered in Tucson, Arizona. 

The scientific community is honored to have the opportunity to conduct astronomical research on I’oligam Du’ag (Kitt Peak) in Arizona, on Maunakea in Hawai‘i, and on Cerro Tololo and Cerro Pachón in Chile. We recognize and acknowledge the very significant cultural role and reverence of I’oligam Du’ag to the Tohono O’odham Nation, and Maunakea to the Kanaka Maoli (Native Hawaiians) community.

Links

• International Dark Sky Week
• Globe at Night website
• DarkSky International
• IAU Office for Astronomy Outreach

Contacts

Josie Fenske
Jr. Public Information Officer
NSF NOIRLab
Email: [email protected]