Most flags abstract the thing they stand for into stripes and emblems. The Earth Day flag skips the abstraction: it is simply a photograph of the planet, centered on a dark blue field, space rendered as fabric. John McConnell made it in 1969, in the narrow window after humans could photograph the whole Earth and before anyone had thought to put the result on a flagpole. It has flown at every kind of environmental gathering since, and it produced one of the odder questions in American copyright law: can anyone own a picture of the world?
A flag for the whole planet
John McConnell was not an environmentalist by profession. Born in 1915, he was a lifelong peace activist of an evangelical bent, a man who spent decades proposing peace projects, hunger campaigns, and world holidays from a base in New York. When NASA's Apollo missions began returning photographs of the whole Earth in 1968 and 1969, McConnell saw in them exactly what he had been arguing for years: from far enough away, there are no borders.
He printed the image on a flag, planet centered on a dark blue field, and debuted it at a Moon Watch gathering in Central Park on 20 July 1969, the night Apollo 11 landed. The photograph on those first flags was a NASA Apollo image from May 1969 (photo 69HC487, taken during Apollo 10), since the famous Blue Marble did not exist yet. Early production versions simplified the planet to white cloud outlines over a light blue disc, a stylization that kept printing costs down and reads today as its own period piece.
Two Earth Days, one flag
McConnell's flag is tied to a specific Earth Day, and probably not the one on your calendar. In the fall of 1969, at a UNESCO conference in San Francisco, McConnell proposed a day to honor the Earth, set on the vernal equinox, the moment when day and night are equal everywhere on the planet. San Francisco issued an Earth Day proclamation in March 1970, and the first celebration was held on 21 March 1970, with McConnell's flags in evidence. The idea gathered impressive signatures: a later Earth Day proclamation McConnell drafted was signed by UN Secretary-General U Thant, Margaret Mead, and dozens of other public figures, and the United Nations still rings the Japanese Peace Bell at its New York headquarters at the moment of the equinox.
One month later, on 22 April 1970, Senator Gaylord Nelson's separate and independently organized Earth Day mobilized some twenty million Americans and became the version the world remembers. The two events shared a name and a planet but not an organizer. McConnell's flag did not take sides. It appeared at equinox observances and April teach-ins alike, and "Earth Day flag" ended up describing it regardless of which Earth Day was meant.
The Blue Marble
On 7 December 1972, the crew of Apollo 17, the last crewed Moon mission, photographed the Earth from about 29,000 kilometers out: fully lit, centered on Africa, with Arabia at the top edge and Antarctica's ice cap visible at the bottom. NASA catalogued it as AS17-148-22727. Everyone else calls it the Blue Marble, and it became one of the most reproduced photographs in history.
Around 1973 McConnell updated his flag to carry it, and that is the version made ever since: the Blue Marble centered on dark blue, usually in 2 by 3 or 3 by 5 foot sizes. The choice of a photograph does something no drawn emblem can. A cartographer must pick a projection and a center, and every choice privileges someone. A photograph just shows where the camera happened to be, and the camera happened to be over Africa. The flag's only editorial decision is the dark blue field, which McConnell read as the space surrounding a small and finite home.
Who owns a picture of the world
The flag's later history belongs to lawyers. NASA photographs are in the public domain as US government works, so the Blue Marble itself belongs to everyone. But the flags were commercialized. Rights to the design passed through a series of hands after McConnell created it, and flags were sold under the registered trademark "The Authentic Earth Flag," with the sellers asserting copyright over the combination of photo and dark blue field.
That claim met its end in Earth Flag Ltd. v. Alamo Flag Co. In May 2000, Earth Flag Ltd. sued a competitor (and eBay) for copyright infringement over lookalike earth flags. In May 2001, the federal district court in Manhattan granted summary judgment against the company: the photograph was public domain, the dark blue background was unprotectable, and placing one on the other involved no creative spark that copyright could recognize. Anyone, in other words, may make an Earth flag. Given what the flag was created to say, it is hard to imagine an outcome McConnell's 1969 self would have found more fitting: the flag of the whole planet turned out to be legally impossible to own.
McConnell died in 2012, at 97. His equinox Earth Day still gets its bell rung at the UN each March, and his flag now outnumbers him by the millions, flying over campuses, climate marches, city halls, and backyards every April.
References
[1] "Flag of Earth," Wikipedia, section on John McConnell's Earth Day flag. https://en.wikipedia.org/wiki/Flag_of_Earth
[2] "John McConnell (peace activist)," Wikipedia. https://en.wikipedia.org/wiki/John_McConnell_(peace_activist)
[3] Earth Flag Ltd. v. Alamo Flag Co., 153 F. Supp. 2d 349 (S.D.N.Y. 2001). https://law.justia.com/cases/federal/district-courts/FSupp2/153/349/2433548/
[4] "John McConnell's Earth flag," Flags of the World. https://fotw.info/flags/qp-3-jmc.html
[5] "Did Earth Day start in San Francisco? It's complicated," San Francisco Examiner archives. https://www.sfexaminer.com/archives/did-earth-day-start-in-san-francisco-it-s-complicated/article_f4d91248-8d2b-5b55-8c76-ea6b26e54f0b.html
[6] NASA, "The Blue Marble" (AS17-148-22727), Apollo 17 image, 7 December 1972. https://www.nasa.gov/image-article/blue-marble-image-earth-from-apollo-17/