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Thirty years ago, on February 14, Voyager 1 recorded its final images before its cameras were shut down to conserve power. Pointing back at the Sun, it took a series of photos that would become the first-ever “family portrait” of the Solar System. In this series was a photo of Earth like no other: this iconic image would become known as the “Pale Blue Dot”.
Revealing Earth as a tiny speck caught in a beam of sunlight bouncing off the spacecraft against a backdrop of empty space, it showed our world in a way we had never seen it before – lonely and vulnerable, a “very small stage in a huge cosmic arena,” as Carl Sagan once described it.
Now NASA has given the photo a 21st-century make-over, using updated technology and modern image processing to reveal our tiny bright speck in greater color and detail than ever.
The term “Pale Blue Dot” was coined by Sagan in his 1994 book of the same name as he reflected on the significance of the photograph. Sagan himself was instrumental in Voyager’s final photo album. It was his idea for Voyager to turn around and take the opportunity to image Earth and its companions before its mission to the edges of the Solar System took it too far away.
So on Valentine’s Day 1990, beyond Neptune and about 6 billion kilometers (3.7 billion miles) from the Sun, Voyager 1 snapped 60 images, including portraits of Venus, Earth, Jupiter, Saturn, Uranus, Neptune, and the Sun, resulting in a composite image NASA dubbed the "Family Portrait of the Solar System." Thirty-four minutes later, its cameras would turn off forever.
In the original Pale Blue Dot, Earth is a mere 0.12 pixels wide (Jupiter and Saturn are both big enough to fill a pixel in their portraits), and seen as just a crescent of light. Rays of sunlight (coming from the bottom left) are scattered within the camera's optics across the image, a result of taking the image so close to the Sun. Purely by coincidence, in the center of one sits Earth. From Voyager's vantage point at the time, Earth was only separated from the Sun by a few degrees.
The newly-processed false-color image, carried out by JPL engineer Kevin M Gill – with input from Candy Hansen and William Kosmann, who were involved in the original image – has had its colors balanced so the main sunbeam looks white, while trying to respect the original data and the intent of those who planned and processed the first photo.
"There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world," wrote Sagan when the image was first revealed to the world.
"To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we've ever known."
So, here is the new image in all its glory. As Sagan said: “Look again at that dot. That's here. That's home. That's us.”
