Earth: The Pale Blue Dot
Planet Earth Seen from 3.7 Billion Miles

Earth: The Pale Blue Dot
Planet Earth Seen from 3.7 Billion Miles

The Pale Blue Dot is a photograph of planet Earth taken in 1990 by Voyager 1 from a record distance, showing it against the vastness of space.

By request of Carl Sagan, NASA commanded the Voyager 1 spacecraft, having completed its primary mission and now leaving the Solar System, to turn its camera around and to take a photograph of Earth across a great expanse of space.

Subsequently, the title of the photograph was used by Sagan as the primary title of his 1994 book, Pale Blue Dot: A Vision of the Human Future in Space.

In a 2001 article by, STScI's Ray Villard and JPL's Jurrie Van der Woude selected this photograph as one of the top ten space science images of all time.

Voyager 1 was launched on September 5th, 1977. Sagan had pushed for Voyager to take a photograph of the Earth when its vantage point reached the edge of the solar system.

On February 14th, 1990, having completed its primary mission, the spacecraft was commanded by NASA to turn around to photograph the planets of the Solar System.

Between February 14, 1990 and June 6, 1990, one image Voyager returned was of Earth, showing up as a "pale blue dot" in the grainy photograph.
The picture was taken using a narrow-angle camera at 32° above the ecliptic and it was created using blue, green, and violet filters.

Narrow-angle cameras, as opposed to wide-angle cameras, are equipped to photograph specific details in an area of interest. The light band over Earth is an artifact of sunlight scattering in the camera's optics, resulting from the small angle between the Earth and the Sun.

Earth takes up less than a single pixel—NASA says "only 0.12 pixel in size."

Voyager took similar photographs of Venus, Jupiter, Saturn, Uranus, and Neptune. When assembled as shown to the right, they create a "portrait" of most of the Solar System.

Mercury's proximity to the Sun prevented it from being photographed and Mars was not visible due to the effect of sunlight on the camera's optics.

NASA compiled sixty images produced into a mosaic called the Family Portrait.

In the book, Sagan related his thoughts on a deeper meaning of the photograph:

From this distant vantage point, the Earth might not seem of particular interest. But for us, it's different.

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 Earth is a very small stage in a vast cosmic arena.

Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot.

Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds.

Our posturings, our imagined self-importance, the delusion that we have some privileged position in the Universe, are challenged by this point of pale light.

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.

The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet.

Like it or not, for the moment the Earth is where we make our stand.

It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny 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.

Seen from 6.1 billion kilometers (3.7 billion miles), Earth appears as a tiny dot (the blueish-white speck approximately halfway down the brown ban) within the darkness of deep space.

The Pale Blue Dot

Carl Sagan - The Pale Blue Dot

The universe is immensely large and possibly infinite in volume. The region visible from Earth (the observable universe) is a sphere with a radius of about 46 billion light years, based on where the expansion of space has taken the most distant objects observed.