The U.S. National Aeronautics and Space Administration (NASA) is unveiling mosaics of Pluto and its largest moon Charon, representing the global response to its #PlutoTime social media campaign. Since the Pluto Time campaign was announced in June 2015, NASA received more than 339,000 visits to the Pluto Time widget and almost 7,000 image submissions from across the globe, including:
- New Zealand
- the U.S.
Thousands of those submissions have now been assembled into three stunning mosaics of Pluto, Charon and a combined image of the two. The files are large enough that, at their current resolution, they would make an eleven-square-foot print. The mosaics include not only dim skies on Earth, but also famous landmarks, selfies and even family pets.
A photo of Clyde Tombaugh, the American astronomer who discovered Pluto in 1930, is embedded in this mosaic of hundreds of images shared during the campaign. If you zoom in on the inset in this image, you can see a photo of Tombaugh and his homemade nine-inch telescope in the region of Pluto’s “heart,” informally named Tombaugh Regio.
- Gigapan Pluto mosaic
- Gigapan Charon mosaic
- View the Pluto Time mosaic of Charon
- View the Pluto Time mosaic of Pluto and Charon
The Pluto Time idea stemmed from a frequently-asked question of New Horizons scientists: “How are you going to take pictures of Pluto, given that it’s so far from the sun?”
The Pluto Time concept and widget was developed by the New Horizons science team so that people could experience the approximate sunlight level on Pluto at noon — generally around dawn or dusk on Earth. Pluto orbits on the fringes of our solar system, billions of miles away. Sunlight is much weaker there than it is on Earth, yet it isn’t completely dark. For just a moment near dawn and dusk each day, the illumination on Earth matches that of high noon on Pluto. NASA calls this “Pluto Time.” If you go outside at this time on a clear day, the world around you will be as bright as the brightest part of the day on Pluto.
“We realized that we could make a Web tool that would estimate approximately when the light levels dropped to Pluto levels,” said Alex Parker, research scientist at the Southwest Research Institute (SwRI) in Boulder, CO. “We looked up tables of illumination levels during various stages of twilight — used to determine when streetlights come on and such — and determined how low the sun would need to be on a clear day to match Pluto. After that, is was a matter of doing the math.”
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The Solar System Exploration Public Engagement team at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, CA, assembled the mosaics, using approximately 1,500 to 2,100 images for each one. The software occasionally repeated images to correctly fill in colors and to provide the proper shape of Pluto and its terrain.
“It’s gratifying to see the global response to Pluto Time, which allowed us to imagine what it’s like on Pluto, some three billion miles away,” said Jim Green, NASA’s director of planetary science. “This is a wonderful example of how space exploration and science unite us with a common bond.”