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It is known that on February 4, 1966, the picture transmitted from the Moon by Luna 9 was intercepted by UK.

The question is, has anybody ever picked up a signal transmitted by a successful Mars lander or rover sent by the United States?

It is quite easy for an US lander to transmit a simple carrier on a stable precise frequency that can be received by big antenna on Earth or in space, a signal whose shift in frequency as seen by the receiver would demonstrate that the US really have working landers on Mars.

enter image description here See: The Luna 9 ‘Space Hack’ – 4th Feb 1966

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    $\begingroup$ im no expert but probably the united states has. $\endgroup$
    – Topcode
    Feb 19, 2021 at 4:50
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    $\begingroup$ I don't understand, are you suggesting that picking up a carrier wave at some particular frequency would somehow prove the Mars rovers aren't fake when all the other already-available evidence isn't proof enough? $\endgroup$
    – TypeIA
    Feb 19, 2021 at 5:25
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    $\begingroup$ I’m voting to close this question because the OP is pushing a theory that the Mars landing is fake. $\endgroup$
    – Organic Marble
    Feb 27, 2021 at 3:42
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    $\begingroup$ This question could be reworked to be curious rather than conspiratorial. "Have any non-governmental agencies picked up transmissions from the surface of Mars?" $\endgroup$
    – Schwern
    Feb 27, 2021 at 5:29
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    $\begingroup$ @Schwern: As I had an answer waiting for this question, I reasked it (without the conspiratorial stuff) here so I could glue my answer onto that. You could attach your answer as well if you wanted. The answer is 'yes' of course, and I've now exchanged mail with people who have heard Perseverance on the surface. $\endgroup$
    – user21103
    Feb 28, 2021 at 13:49

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Along with terrestrial operations by various radio telescopes the various agencies with Mars orbiters co-operate to capture data during landings including ESA Mars Express supporting MSL and Phoenix.

There is a shared protocol/hardware system for communicating between craft on and around Mars which allows agencies to share available bandwidth for earth uplink.

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    $\begingroup$ Scott Tilley (a hobbyist) of Roberts Creek, British Columbia has picked up signals from China’s Tianwen-1 spacecraft, NASA’s Mars Reconnaissance Orbiter, and the United Arab Emirates’ Hope probe–all orbiting Mars approximately 200 million kilometers away. (see: spaceweatherarchive.com/2021/02/16/ham-radio-signals-from-mars). If this guy is able to listen to spacecrafts circling Mars, then most countries in the world have the necessary equipment for receiving basic signals (like carriers) from the US Mars rovers and landers. You do not need expensive facilities like DSN. $\endgroup$
    – azot
    Feb 25, 2021 at 19:40
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    $\begingroup$ @azot Perhaps we should just quote Scott Tilley: 'Tilley plans to listen but he doesn’t expect a strong signal. "Perseverance does not have a very large antenna," says Tilley. "It doesn’t need one because it can use other NASA spacecraft in Mars orbit as relays. The signal will therefore be weak and I doubt many amateurs will record the landing in Jezero crater." So, I don't know, but perhaps this is why you need a whacking great dish to hear it, like ... the DSN had. $\endgroup$
    – user21103
    Feb 25, 2021 at 20:32
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    $\begingroup$ @azot sounds like you have a valid answer there - it is perfectly fine to answer your own question if in doing further research you find something. I have seen a lot of social media buzz about amateur reception of various space probes but do not follow the scene closely enough to produce a properly sourced answer for the just Mars probes. Along with amateur radio folk, highly likely Universities with radio telescopes will have also given it a try. $\endgroup$
    – GremlinWranger
    Feb 26, 2021 at 7:56
  • $\begingroup$ @GremlinWranger , My question was about landers or rovers, in other words radio signals coming from the surface of Mars, not its orbit. $\endgroup$
    – azot
    Feb 26, 2021 at 11:08
  • $\begingroup$ @Schwern , It can transmit data directly to Earth. See: "Transmitting data directly to and from Earth" (mars.nasa.gov/mars2020/spacecraft/rover/communications) "Transmission/ Reception Rates: 160/500 bits per second or faster to/from the Deep Space Network's 112-foot-diameter (34-meter-diameter) antennas or at 800/3000 bits per second or faster to/from the Deep Space Network's 230-foot-diameter (70 meter-diameter)" $\endgroup$
    – azot
    Feb 27, 2021 at 4:49
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Yes, Viking communicated directly with Earth. Not to say others have not, I mention this because I found JPL's very detailed Telecommunications and Data Aquisition Systems Support for the Viking 1975 Mission to Mars. Appendices C and D contain a log of all direct contact with the Viking landers.

Most Mars landers these days prefer to relay through a growing network of international spacecraft in orbit around Mars. This saves power, increases bandwidth, and simplifies transmission. The Viking landers also used dedicated relaying orbiters, but they were also capable of transmitting direct to Earth via a high gain S-Band dish.

enter image description here

A stored program in the lander turned a transmitter on at a specified time corresponding to each Earth view period, and a long-term stored program maintained the antenna's Earth-pointing direction. The Earth-pointing antenna program was written to be valid through 1994.

This was done using the Deep Space Network, three 70 meter dishes located 120 degrees apart around the world. The same network is used today.

It is quite easy for an US lander to transmit a simple carrier on a stable precise frequency that can be received by big antenna on Earth or in space, a signal whose shift in frequency as seen by the receiver would demonstrate that the US really have working landers on Mars.

Let's clear this up. It is not quite easy.

You gave an example of receiving a signal from the Moon. The Moon is about 400,000 km from the Earth. It is tidal locked to the Earth. It has no atmosphere to interfere with radio communications. Light delay is about 1.5 seconds.

Mars is, depending on the date, between 60,000,000 and 400,000,000 km away from the Earth, 100 to 1,000 times further than the Moon. It rotates relative to the Earth. It has an atmosphere. Light delay is 200 to 1300 seconds making targeting tricky.

It's a lot harder to communicate with Mars than the Moon.

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    $\begingroup$ Has the Curiosity rover ever communicated directly with Earth via its high-gain antenna? Signal strength & data rate? $\endgroup$
    – uhoh
    Feb 27, 2021 at 6:08
  • $\begingroup$ My question is about witnesses. A state can not be its own witness. I know that DNS received signals from the surface of Mars but this network is controlled by the US What I want to know is whether some other state, or hobbyists, at least claimed receiving even a rough carrier from a martian lander or rover. $\endgroup$
    – azot
    Feb 27, 2021 at 6:29
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    $\begingroup$ @azot Yes, all the various people and organizations who run the DSN. The DSN is operated for NASA by JPL which is managed by Caltech. Instituto Nacional de Técnica Aeroespacial runs the site in Spain. CSIRO manages the Canberra site. Your curiosity is fine, but when you drift into Moon hoax conspiracies you disrespect all those people who work hard to make these missions possible. $\endgroup$
    – Schwern
    Feb 27, 2021 at 6:53

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