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<meta http-equiv="description" content="Learn the 'secret code' spacecraft use to send images back from space. Never quite understood binary or hexadecimal notation? Now's your chance to get it clear.">
<meta name="author" content="Diane Fisher, diane.k.fisher@jpl.nasa.gov">
<title>Language for sending pictures through space</title>
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<font face="COMIC SANS MS,ARIAL,HELVETICA" size="+3" color="ORANGE"><b>What is the "secret code" used by the Voyager spacecraft? </b>
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<p><img src="planet_girls.jpg" width="350" height="240"></center>
<p><font face="COMIC SANS MS,ARIAL,HELVETICA" size="+2"><b>Amazing Fact:</b></font>
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<b>In sending us the beautiful, true-color planet pictures below, the spacecraft communicated using only ones and zeroes! </b></blockquote>
<p>Pass your mouse over the pictures to see what the raw data looked like before processing.
<p>All these pictures were made by the Voyager spacecraft. Find out more amazing facts about their <a href="vgr_fact3.htm">Grand Tour of the outer planets</a> between 1979 and 1989.</font>
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<td halign="RIGHT"><a href="#" onmouseover="imgOn('img7')" onmouseout="imgOff('img7')"><img name="img7" border="0" width="300" height="203" align="RIGHT" src="jupiter_io2.jpg"></a>
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<td><font face="COMIC SANS MS,ARIAL,HELVETICA"><i>This is Jupiter, the fifth planet from the Sun, and its moon Io.</i>
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<p><a href="#" onmouseover="imgOn('img8')" onmouseout="imgOff('img8')"><img name="img8" border="0" width="200" height="286" align="RIGHT" src="saturn2.jpg"></a>
<td><font face="COMIC SANS MS,ARIAL,HELVETICA"><i>This is majestic Saturn, sixth from the Sun, with its jaunty rings. If you look very closely, you can see four of Saturn's moons, too.</i>
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<td valign="MIDDLE"><font face="COMIC SANS MS,ARIAL,HELVETICA"><i>This is a montage of all four of the outer planets visited by Voyager 2. They are (front to back, farthest from Sun to nearest) Neptune, Uranus, Saturn, and Jupiter.</i>
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<td colspan="2"><font face="COMIC SANS MS,ARIAL,HELVETICA" size="+1">The signals Voyager sent to Earth to give us these pictures looked something like this:
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. . . 1101 0010 1001 0101 0000 1011 0001 . . .</center>
<p>How did we ever make enough sense of these 1's and 0's to get these magnificent images?
<p>Spacecraft engineers and computer scientists have had to solve many big problems. But none of these problems could be tackled without one thing: a special language so people could communicate with machines. Even though . . .
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<li>Spacecraft seem very smart.
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<li>The huge dish antennas that pick out the spacecraft's signal from millions of miles away seem very smart.
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<li>The computers that decode and process the signals into pictures seem very smart.
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. . . none of these machines is smart enough to learn English, or Spanish, or any other human language. These machines understand only two ideas:
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<p>So the big question is,
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<font face="COMIC SANS MS,ARIAL,HELVETICA" size="+1" color="ORANGE"><b>How do we feed complicated information IN and get complicated information OUT, if we can only say "ON" and "OFF"? </b></font>
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<td colspan="2" align="RIGHT"><font face="COMIC SANS MS,ARIAL,HELVETICA" size='+1"'><a href="vgr_fact2.htm">Do you REALLY want to know? OK, let's find out!</a>
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