Let us take a journey from the surface of the Earth to the edge of our solar system. Along the way, we’ll take a look back at our planet, where we can appreciate the vast distances of space, and the uniqueness of our home – a Pale Blue Dot in a sea of stars and galaxies.
As we move to the height of the space shuttle Discovery (from 175km to 960km), we can see the beautiful auroras, created when solar winds crash into the Earth’s atmosphere at the poles.
As the Earth rotates and transitions from night to day, we see the north Atlantic Ocean from the Equator through Western Africa, toward Iceland and Greenland, over Scandinavia, France, Spain and more. Showing a curbed “terminator” from night to day, the image is a compilation from NASA.
At around 700 kilometers above the Earth, NASA’s Terra satellite captured the most detailed image of the Earth yet. The satellite used a device called MODIS (Moderate Resolution Imaging Spectroradiometer), which serves as an integrated tool for observing a variety of terrestrial, oceanic, and atmospheric features of Earth. (image credit: NASA)
Another view, from space shuttle Discovery, shows the moon setting from the Earth’s limb. Since the moon is in a synchronized rotation with the Earth, we only see one side of its surface. Pictures like this give us a more complete view.
Next, we view of the Earth rising over the Moon’s horizon. This image was taken during the Apollo 11 mission in 1969. The lunar terrain pictured is in the area of Smyth’s Sea on the near side. While the Lunar Module “Eagle” was on the surface to explore the Sea of Tranquility, the Command and Services Module “Columbia” remained in lunar orbit. (image credit: NASA)
Further still, we venture outward towards Mars. Below, the Earth and moon seen from Mars in May, 2003. At the time the image was taken, the Earth was 142 million kilometers from Mars (image credit: NASA/JPL-Caltech/University of Arizona)
Recently, NASA released the first image of Earth from the surface of another planet. It was taken by the Mars Exploration Rover Spirit, one hour before sunrise on the 63rd Martian day of its mission. (image credit: NASA/JPL/Cornell/Texas A&M)
From Mercury, the Earth almost looks as if it is a binary system. The photos below were taken by NASA’s MESSENGER (MErcury Surface, Space ENvironment, GEochemistry and Ranging) spacecraft.
As we venture further still, the Earth-Moon system is visible as a bright blue point on the right side of the image above center. Here, the Cassini Space Probe is looking down on the Atlantic Ocean and the western coast of north Africa.
A magnified view of the image taken through the clear filter shows the Moon as a dim protrusion to the upper left of the Earth. Seen from the outer solar system through Cassini’s cameras, the space between the Earth and moon is nothing more than a few pixels across, spanning an actual distance of approximately 384,000 kilometers (the average distance between the Earth and the moon). (image credit: NASA/JPL)
Finally, seen from 6 billion kilometres (3.7 billion miles), Earth appears as a tiny dot (the blueish-white speck approximately halfway down the brown band to the right, circled) within the darkness of deep space. This photograph was taken in 1990 by the Voyager 1 spacecraft, on it’s way out of the Solar System. This Pale Blue Dot, barely recognizable from this distance, is the only home we’ve ever known.
In a commencement address delivered May 11, 1996, Carl 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. Consider again 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.”
Carl Sagan, May 11th, 1996