A Brief Word on Night Skies: A Grand Canyon Ranger Speaks to Astronauts

Star trails over the Desert View Watchtower, Grand Canyon National Park. Dan Pawlak, NPS.

On June 9, 2022, astronauts of NASA's SpaceX Crew-2 mission — back since the previous November from a record-setting six months on the International Space Station — visited National Park Service headquarters in Washington for a celebration of science, astronomy, art and exploration, and to learn about the Park Service's work to protect dark skies. Grand Canyon ranger Rader Lane opened with this talk, summarized here.

The sky is part of every place

Across Grand Canyon and the parks around it are ancient structures aligned to true north, notches in adobe walls that catch the light at the solstices, "Sun Dagger" petroglyphs marking the solstices with light and shadow, and rock art that may record supernovae, eclipses, comets and meteor showers. Tribes today tell constellation stories as rich as the Greek classics. The night sky has been part of the human story forever — and knowing a place means knowing how its Indigenous peoples read the Sun, Moon and stars in its landscape. A region's sky, Lane argued, belongs to its sense of place as much as its geology and ecology.

The Supernova Pictograph at Chaco Culture National Historical Park — rock art across the Southwest speaks to a deep connection with sky-watching. NPS.

Astronomy and public lands

• A telescope on the rim: in 1928, astronomer George Ritchey proposed building the world's largest telescope at the edge of the Grand Canyon — dubbed the "desert watchtower" by New York Times writers. Edwin Hubble, weeks before publishing the paper that transformed our picture of the universe, paused his research to see the canyon's dark skies. The telescope was never built, for administrative reasons, but some historians think architect Mary Colter took the idea, or at least the name, for her Desert View Watchtower from the articles about it.
• Apollo in the canyon: in 1964, Apollo astronauts hiked to the canyon's bottom through every layer of ancient rock, studying geology to use on the Moon. Among them was Neil Armstrong, a few years before he stepped onto another world. Lane recalled John Muir's words on the canyon: "The view down the gulf of color and over the rim of its wonderful wall, more than any other view I know, leads us to think of our earth as a star with stars swimming in light, every radiant spire pointing the way to the heavens."

George Ritchey's proposed telescope, drawn onto a photograph of the Grand Canyon and published in a French magazine in 1928.

Neil Armstrong on the South Kaibab Trail, headed for Phantom Ranch, during Apollo geology training in 1964.

The last dark places

More than 80% of people in the United States can no longer see the Milky Way from home because of light pollution, which makes national parks the last sanctuaries of natural darkness. On a moonless summer night at Grand Canyon and other western parks, the Milky Way's center in Sagittarius is bright enough to cast a shadow.

Sharing the dark

• Star parties: the Park Service works with NASA and others to bring science and wonder to visitors. The Grand Canyon Star Party drew 12,544 visitors in 2019, with 81,095 "eyeballs to eyepieces" contacts and 4,370 people at theater talks; in 2022, speakers from NASA's Goddard Space Flight Center and Jet Propulsion Laboratory were to address several hundred visitors a night.
• Astronomer in Residence: Grand Canyon and its nonprofit partner, the Grand Canyon Conservancy, invite astronomers, writers and artists to live in the park and work under one of the country's most pristine night skies.
• Rangers: across the country they give constellation talks, telescope viewing and full Moon walks, use audience-centered programs, host Indigenous sky stories, and spread the word online about light pollution, darkness and science literacy — and star talks are the most popular programs rangers give.

The Grand Canyon Star Party, one of many night-sky festivals across the National Park Service. NPS.

An International Dark Sky Park

Grand Canyon became an International Dark Sky Park in 2019, joining dozens of parks and public lands. It inventoried 5,094 lights and retrofitted most to be night-sky friendly — making one of the most visited parks also one of the darkest, and among the largest and most complex dark sky parks anywhere. Parks now let people everywhere feel what our ancestors — and astronauts — know: the sublime, that mix of awe and terror at nature's vastness that humbles and connects us. Nowhere else, Lane closed, can you stand between so much deep time below in stone and above in stars — exploring outer space to understand our inner space.

Sources

Based on "A Brief Word on Night Skies," a talk by Grand Canyon ranger Rader Lane, National Park Service, quoting John Muir; a work of the United States government in the public domain. Related: the astronauts' visit. A light-pollution map from a scientific journal, an artist's graphic and an individually credited photograph are left out.