The historic photograph of distant Earth, taken by the Voyager 1 spacecraft as it was making its way into interstellar space is one of the most celebrated photographs in the history of space exploration, and it was taken 30 years ago today.
On February 14, 1990, exactly thirty years ago today, NASA’s Voyager 1 spacecraft turned its cameras to take a series of historic images of the inner planets of the solar system.
The spacecraft was accelerating away from the Earth, and nine years and three months after its last planetary encounter, and some four billion miles away from the Sun, a distance much farther away than the orbit of Neptune, Voyager 1 acquired 60 individual exposures of seven of our eight solar system’s planets, and the sun shining in the distance, among a massive cosmic sea of space.
As the spacecraft was hurtling towards the outer confines of the solar system, NASA engineers commanded the spacecraft to turn its cameras around and “show” them what it was seeing.
Eventually one of the images the spacecraft snapped became one of the most iconic photographs in the exploration of space by the human race.
The images would eventually be known as the “Pale Blue Dot.”
The term was coined by Carl Sagan in his reflections of the photograph’s significance, documented in his book of the same name, Pale Blue Dot:
“Look again at that dot. That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every “superstar,” every “supreme leader,” every saint and sinner in the history of our species lived there-on a mote of dust suspended in a sunbeam.”
The Pale Blue Dot: Revisited
The Pale Blue Dot is in fact just part of the solar system’s family portrait snapped by Voyager 1. Although it wasn’t the spacecraft primary goal, nor was Voyager 1 intended to do so, the idea came to life thanks to Sagan, who couldn’t resist the opportunity to see the solar system’s planets, and our small island in space reflected as a small blue dot, at a distance of nearly 4 billion miles.
“Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves,” Sagan wrote in his 1994 book.
For the 30th anniversary, NASA has released a new version of the historic image: Revisited the Pale Blue Dot.
The original image taken by Voyager shows Earth as a small birth speck within the sunbeam, towards the center of the image. As noted by NASA, Earth–the small, pale blue dot–occupies less than a single pixel in Voyager 1’s photograph, and thus is not fully resolved. (The actual width of the planet on the sky was less than one pixel in Voyager’s camera.)
In comparison, Jupiter and Saturn were large enough to fill a full pixel in their family portrait images taken by Voyager 1.
NASA explains that just as the original version of the Pale Blue Dot, the new version is also technically a “false-color” view, as the color-filter images used were mapped to red, green and blue, respectively.
In the revisited image of the Pale Blue Dot, the color was adjusted so that the primary sunbeam (which overlays Earth) appears white, like the white light of the Sun.
On February 14, 1990, NASA’s Voyager 1 spacecraft snapped a historic image of Earth known as the Pale Blue Dot. Here’s NASA’s revisited version of the image.