It may not be as well known as the Mona Lisa, but Charles O’Rear’s photo, Bliss, may have been viewed as many times, if not more.

Published in 2002, the photo got most of its distribution as the default desktop wallpaper for Microsoft’s Windows XP’s “Luna” theme. O’Rear snapped the photo while he was on break from another assignment in California’s Napa Valley. O’Rear, a former National Geographic staffer, didn’t disclose what Microsoft paid for rights to the photo, but O’Rear has said it’s “extraordinary.”

Long acknowledged for its exposure across the globe, the photo drew attention once again on Monday when a photo blog claimed the audience for the photo at 1 billion. The entry got wide circulation on Google+.

However, O’Rear told Mashable that the 1 billion figure “has always been a guesstimate.” However, “All the folks I talk with agree it is the most ‘recognizable’ photo ever. If it were shown to a villager in rural China, for example, good chance they would recognize it. If it were shown to astronauts on the ISS, good bet they would know it, too. I have seen it appear in photos of the White House situation room, the Kremlin, etc.”

Can you think of a photo that might have been seen more times?