If you’re in love with space then you’ll fall head over heels for this: it’s a picture of Earth taken from the Voyager 1 spacecraft after it passed the orbit of Pluto back in 1990—on Valentine’s Day, no less. That image of our planet from almost 4 billion miles away inspired Carl Sagan to write his famous “Pale Blue Dot” passage, which reminds us that we are all just riding on “a mote of dust suspended in a sunbeam.”
On February 14, 1990, after nearly 13 years of traveling the Solar System, Voyager 1 passed the orbit of Pluto and turned its camera around to take a series of photos of the planets. The image above shows those photos, isolated from the original series and are left to right, top to bottom: Venus, Earth, Jupiter, Saturn, Uranus, and Neptune.
From that distance, over 4 billion miles from the Sun, the planets each appear as little more than a bright dot against the vastness of interplanetary space and the glare of light from the Sun.
“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. … There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world.”
– Carl Sagan
It was the unique perspective above provided by Voyager 1 that inspired Carl Sagan to first coin the phrase “pale blue dot” in reference to our planet and in the title of his book. And it’s true…from the outer Solar System, Earth is just a pale blue dot in the black sky… just another light in the dark. It’s a sobering and chilling portrait of our world but inspiring too, as the Voyager 1 spacecraft is the furthest human-made object in existence and getting further every second. It’s still transmitting data back to us too, although faintly as it’s very far now…over 12.8 billion miles away.
In the video below Carl Sagan’s wife Ann Druyan talks about the significance of the pale blue dot image:
Although Voyager 1 no longer has the power or software on board to take any more images of the planets, in February 2013 it was spotted from Earth by the National Radio Astronomy Observatory’s 5,000-mile-wide Very Long Baseline Array (VLBA), a telescope network that stretches from Hawaii to St. Croix. Here’s what Voyager 1 looked like in radio wavelengths:
Voyager 1’s main transmitter radiates around 22 watts, which is comparable to a typical ham radio or a refrigerator light bulb. Though incredibly weak by the standards of modern wireless communications, Voyager 1’s signal is bright when compared to most natural objects studied by radio telescopes.
Read more about the Voyager mission here.