RE: New Images Of Pluto From 7,750 Miles
July 18, 2015 at 11:46 am
(This post was last modified: July 18, 2015 at 11:57 am by Anomalocaris.)
(July 18, 2015 at 5:14 am)zebo-the-fat Wrote: The thing that amazes me about this whole thing is the fact that it is sending data back from 4.7 billion miles away using only a 12 watt transmitter! (just think of something with almost one tenth the power of a 100 watt light bulb... could you even see it from that distance?)
At least you have a big 3 meter highly directional antenna talking to a 70 meter highly directional antenna here, so it's not analogous to an omnidirectional light bulb.
Much more impressive was NASA's effort to listen in on possible transmissions from a lost polar lander, as I recall. The lander did not communicate with either orbital relay satellite or directly with ground. NASA thought the main high gain antenna directional might not have deployed on the lander.
But the lander had a back up 1 watt omnidirectional (!) antenna for communicating with relay satellite.
NASA clearly believed its ground stations on earth could pickup the broadcast from a 1 watt omnidirectional antenna on Mars!
That is like listening in on the signal from a cellphone handset from distance of Mars.
It would be interesting to calculate how many photons from that transmission would arrive each second on a square meter of receiving surface on earth.
