Every so often, in movies and whatnot, you hear about all the EM broadcasts polluting space from Earth. Could an astronaut on the ISS pick these up and actually watch/listen to Earth media?
depends on what station, the nature of the signal and power.
they do communicate by radio and tv.
radio, tv, phone and data are relayed through satellites.
so lots of signals go into space.
(Not an industry professional, so I may well be corrected by more informed minds…)
Short answer: probably not (or at least, not for very long), for a couple of reasons.
First of all, digital TV signals (which is how US TV stations, at least, broadcast now) don’t reach very far – at least, not far enough to be “watchable” on a TV on the ISS. The ISS orbits at a height of about 420 miles above the Earth’s surface; from what I’ve found, digital TV signals only have an effective (i.e., watchable) range of 40 to 50 miles. Even if we’re talking about the old-style analog signals, the watchable range for a TV station would likely still be far less than 420 miles.
FM radio signals also don’t effectively carry very far, also apparently topping out at 50 miles or so. AM signals carry further, and even on the surface of the earth, it’s often possible to pickup “skipped” AM signals from many hundreds of miles away…this is often particularly true of “clear channel” AM stations, which boost their broadcast wattage at night.
So, in theory, it seems like you might be able to pick up an AM signal on the ISS…if it were stationary, or slowly orbiting. But, that’s the other complication – the ISS orbits the Earth at a speed of 17,100 MPH (or, 4.75 miles per second). At that speed, the ISS would be moving in and out of any particular station’s signal in seconds, or minutes at the most.
The reason tv signals don’t reach very far is because the earth is curved- they won’t extend over the horizon.
Clearly the ISS doesn’t have this issue, but there are other ones- a big one is the fact that TV antennas are oriented to broadcast their signals in the horizontal plane.
I imagine the ionosphere might cause some problems as well.
Even if the signal can reach into space (it probably can), and you tune your TV to channel 30, how can your TV distinguish amongst the scores of broadcasts on channel 30?
Amateur radio operators can and do transmit to the ISS all the time, and the ISS transmits back. All you need is the right equipment pointed in the right direction.
The last time I checked, it was hard to get digital TV to work while moving at car speeds, let alone at space station speeds. (I was looking to see if there were any mobile ATSC tuners that my dad could get to replace being able to get channel 6 on 87.7. Everything I read at the time said that even a little movement would mess up the timing of the signal and the decoder wouldn’t work.)
What works in Hollywood movies don’t work well in the real world.
Radio signals on earth hardly make it in space.If you where on moon or mars 95% of the radio signals on earth you would not pick up.
What does that have to do with anything? The Moon and Mars are much further away than the ISS.
The idea in Hollywood movies you can pick up any radio signal in space no matter how far away you are.
I don’t think I’ve ever seen that concept in a movie.
I’ve never seen it in a movie, but I read a short story way back about an astronaut marooned light-years from home. The rest of the crew o his mission is dead and he is slowly going crazy from the isolation, until he discovers that he’s just the right distance from Earth to pick up TV signals from the 1950s. The voices and pictures from home keep him sane until rescuers arrive. I don’t remember much more than that, though I probably read it in Asimov’s SF Magazine.
Today’s Fresh Air radio program was an interview with astronaut Chris Hadfield. He mentioned an ISS computer software installation gone wrong, knocking out the spacecraft’s regular communications with Mission Control. He said he got on the ham rig to some operators in Brazil and asked them to phone Houston, and then when they got over Russia the cosmonauts could talk using “regular VHF radios” to get things sorted out.
No, the ISS could not reliably pick up VHF or UHF television signals transmitting NTSC, PAL, or SECAM signals in orbit. It may get intermittent signals depending on atmospheric conditions but would rapidly pass out of range. The same is true for standard frequency modulation (FM) transmissions as they just don’t have the power to reach orbit even in line of site. The ISS may be able to receive amplitude modulation (AM) transmissions, and can certainly receive single sideband (SSB) transmissions from ham operators, albeit at low fidelity. Deliberate transmission to spacecraft and the ISS uses highly directional transmission to reduce the overall power requirements but this also requires accurate pointing and tracking. It is possible to receive transmissions from the ISS with a non-diectional handheld receiver but only infrequently. Orbcomm, Iridium, and Globalstar all allow terrestrial users to maintain contact using handheld transmitters/receivers only by using a very complex system which hands off communications between satellites as they pass into and out of range.
Stranger
Oh, man, I think I’d just get even crazier if forced to watch 50s TV shows over and over.
But assuming he’s more or less stationary with respect to earth, at least compared to the speed of light/radio, every year he’d get to watch the next year’s episodes. IOW, in a few years he’d be watching early 1960’s TV.
That’s MUCH better, isn’t it??
Now I remember a ham operator telling me that they have this event where when the ISS flies over the US people with ham sets will call up to the ISS and the people on the ISS would respond. So the conversation would go like “wmh409 to ISS” then “wmh409 acknowledge”. I guess it was fun to see how many ham operators would get replies.
So the meme that when our first extraterrestrial visitors arrive, they will know a lot about us, from having seen decades worth of I Love Lucy, Dragnet, Bonanza, etc. broadcast out into interstellar space is really not accurate?
No, because have you ever tried to adjust rabbit ears in zero-G?!