Pale blue dot
Pale Blue Dot (PBD, English for pale blue dot ) is the name of a photo of the earth that was taken at the suggestion of the American astronomer Carl Sagan by the Voyager 1 space probe from a distance of about 6 billion kilometers or 40.5 AU . At the time, this was the greatest distance to Earth that a photo was ever taken, and to this day it is still the greatest distance photograph of the Earth.
The picture was taken on February 14, 1990 as part of a series of 60 pictures. In addition to the sun, the series contains images of six planets. Scientists voted the photo in 2001 as one of the ten best photos in space science.
Creation of the photo
At the suggestion of Carl Sagan, after completing the primary objectives, Voyager 1 was rotated 180 degrees and recorded the series of 39 wide-angle and 21 telephotos :
At the time it was taken, the probe was about 6 to 7 billion kilometers from the Sun and 32 degrees above the ecliptic , so it was looking at the solar system from above . On the collage you can see from left to right: Jupiter , the earth, Venus , the sun , Saturn , Uranus and Neptune . Mercury and Pluto cannot be seen in the photo because they were too small to be captured by the cameras. The Mars was located at the time of shooting too close to the sun and was outshone by her.
The earth was recorded with a Vidicon camera with a telephoto lens. The camera has seven color filters, the blue, green and purple filters were used for this picture. The rays passing through the image were created as the scattering of sunlight on the camera optics, as they were not designed to be aimed directly at the sun. The earth is only 12% the size of a single pixel .
The wide-angle view of the sun was taken with the darkest filter and the shortest possible exposure time (5/1000 seconds) to avoid overexposure. From this distance, the sun was only 1/40 of the apparent diameter as seen from Earth, but is still 8 million times brighter than the next brightest star Sirius .
After the recordings were completed, Voyager's camera systems were permanently deactivated. The technology on earth necessary to interpret the image data has also been dismantled.
For the 30th anniversary of this photo, NASA published a new version of the photo. The original image data were reprocessed with modern image processing systems in accordance with the specifications and intentions.
For many years, the “family portrait” series held the record for the longest distance to the earth, 6 billion kilometers or 40.5 AU. Only the New Horizons space probe was able to break this record and take pictures from an even greater distance. On December 5, 2017, images were taken at a distance of 6.12 billion km or 40.9 AU. These images show a star cluster and the two Kuiper belt objects 2012 HZ84 and 2012 HE85 . The family portrait is thus still the picture of the earth from the greatest distance from it.
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Book and reflections by Carl Sagan
The picture inspired Sagan to his book Pale Blue Dot: A Vision of the Human Future in Space (German title: "Blauer Punkt im All. Our home universe "). the author, who with the book and the television series Cosmos: A Personal Voyage (German title " Unser Kosmos ") brought complex scientific topics such as the origin of the universe, the galaxy and life closer to the general public, mixes philosophical considerations in this book about the position of man in the universe with explanations about the contemporary knowledge about our solar system. In addition, there are video collages that have been accompanied by sound recordings by Carl Sagan.
"We succeeded in taking that picture [from deep space], and, if you look at it, you see a dot. That's here. That's home. That's us. On it, everyone you ever heard of, every human being who ever lived, lived out their lives. The aggregate of all our joys and sufferings, thousands of confident religions, ideologies and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilizations, every king and peasant, every young couple in love, every hopeful child , every mother and father, every 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 in 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 the dot on scarcely distinguishable inhabitants of some other corner of the dot. 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 bacon 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. It is up to us. It's been said that astronomy is a humbling, and I might add, a character-building experience. To my mind, 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 and compassionately with one another and to preserve and cherish that pale blue dot, the only home we've ever known.
(We managed to capture this picture [from deep space] and when you look at it you see a point. [This point] is here. It's our home. We are that. Everyone has that you have on it have ever heard, every person who has ever lived, lived his life, the totality of all our joys and sorrows, thousands of self-convinced religions, ideologies and economic doctrines, every hunter and gatherer, every hero and coward, every creator and destroyer of civilizations, every king and farmer, every young couple in love, every hopeful child, every mother, every father, every inventor and discoverer, every moral teacher, every corrupt politician, every superstar, every supreme leader, every saint and sinner in the world History of our species lived there on a speck of dust in a ray of sunshine.
The earth is a very small stage in a huge cosmic arena. Think of the rivers of blood wasted by all these generals and emperors, that in glory and triumph they might for a moment become masters of a fraction of that point. Think of the endless atrocities committed by the residents of one corner of the point against the indistinguishable residents of another corner of the point. How common are their misunderstandings, how eager they are to kill each other, how ardent their hatred is. Our [proud] posturing, our imagined importance, our mistake of a privileged position in the universe is challenged by this pale blue point of bright light.
Our planet is a lonely flake in the great enveloping cosmic darkness. In our darkness - in all this vastness - there is no indication that help will come from elsewhere to save us from ourselves. It has been said that astronomy is a humbling, and I might add, a character-building experience. In my opinion, there is perhaps no better demonstration of the stupidity of human imaginations than this distant picture of our little world. It underlines to me our responsibility to be more friendly and compassionate with one another and to preserve and care for this pale blue dot, the only home we have ever known. "
The Day the Earth smiled
A similar picture was taken during the Cassini-Huygens mission on July 13, 2013: A picture was taken from a perspective in the shadow of Saturn , showing Earth, Mars and Venus. A recording with a smaller angle could also capture the earth's moon. The audience on Earth had been asked to look towards Saturn and smile at the time of the recording.
See also
Web links
Individual evidence
- ↑ a b space.com: Experts Pick: Top 10 Space Science Photos ( Memento from July 6, 2008 in the Internet Archive ) September 25, 2001.
- ↑ a b Solar System Portrait - 60 Frame Mosaic , visibleearth.nasa.gov
- ↑ Emily Lakdawalla, Charlene Anderson: Twenty years since Voyager's last view. planetary.org, February 12, 2010, accessed August 9, 2014 .
- ↑ PHOTO CAPTION, June 6, 1990, P-36087A & B, Voyager , Public Information Office, Jet Propulsion Laboratory, California Institute of Technology, June 6, 1990 (txt)
- ↑ We're scientists and engineers on NASA's Voyager mission. Our spacecraft is now in interstellar space. Ask Us Anything! on reddit.com
- ↑ 'Pale Blue Dot' Revisited. Retrieved June 25, 2020 .
- ↑ JHUAPL: New Horizons Captures Record-Breaking Images in the Kuiper Belt . In: New Horizons . ( jhuapl.edu [accessed February 20, 2018]).
- ↑ ISBN 0679438416 Pale Blue Dot: A Vision of the Human Future in Space
- ↑ ISBN 3828934013 Blue point in space . Our home universe
- ^ YouTube ( Memento from October 21, 2013 in the Internet Archive ) The Pale Blue dot
- ↑ YouTube We Are Here: The Pale Blue Dot
- ^ Sagan, Carl (1997). Pale blue dot. United States: Random House USA Inc. ISBN 9780345376596 .