Re:Jupiter’s North Pole Unlike Anything Encountered in Solar...
by krylon on Saturday September 03, 2016 @04:50PM
(#12421136)
> Just imagine sending data to earth at 160 bps from a distance of 20 billion kilometers and 17 billion kilometers^ [3] , respectively, for Voyager 1 and Voyager 2.
Sending data - regardless of bandwidth - over these distances is very impressive in my book. Let alone sending a computer so far and have it still work after all these years.
I look at the Voyager (1 and 2) data whenever I feel like comparing things to what we have today, and I always end up being overwhelmed by the facts, figures and what humans have achieved. I can't help but be awed.
Quoting from the Voyager FAQ [1]:
> Question: How fast are the Voyager computers?
> Answer:Not very fast compared to today’s standards. The master clock runs at 4 MHz but the CPU’s clock runs at only 250 KHz. A typical instruction takes 80 microseconds, that is about 8,000 instructions per second. To put this in perspective, a 2013 top-of-the-line smartphone runs at 1.5 GHz with four or more processors yielding over 14 billion instructions per second.
Quoting from the Voyager Interstellar Science page [2]:
> Science data are returned to earth in real time at 160 bps.
Just imagine sending data to earth at 160 bps from a distance of 20 billion kilometers and 17 billion kilometers^ [3] , respectively, for Voyager 1 and Voyager 2. The time it takes light to travel between earth and Voyager 1 and Voyager 2 is currently about 19 hours and 15.5 hours^, respectively. (Some other communication is collected and sent at 115 kbps)
^: These figures are rounded since it doesn't make a huge difference to me at this magnitude, and also, the distance from earth to these two spacecraft does sometimes decrease due to earth's revolution around the sun.
[1]: http://voyager.jpl.nasa.gov/faq.html
[2]: http://voyager.jpl.nasa.gov/science/
[3]: http://voyager.jpl.nasa.gov/where/