Hams See Dark Side Of The Moon Without Pink Floyd

Ham radio operators bouncing signals off the moon have become old hat. But a ham radio transmitter on the Chinese Longjiang-2 satellite is orbiting the moon and has sent back pictures of the Earth and the dark side of the moon. The transceiver’s main purpose is to allow hams to downlink telemetry and relay messages via lunar orbit.

While the photo was received by the Dwingeloo radio telescope, reports are that other hams also picked up the signal. The entire affair has drawn in hams around the world. Some of the communications use a modulation scheme devised by [Joe Taylor, K1JT] who also happens to be a recipient of a Nobel prize for his work with pulsars. The Dwingeloo telescope has several ham radio operators including [PA3FXB] and [PE1CHQ].

You can find technical particulars about the satellite on its web page. There are also GNU Radio receivers and information about tracking. If you want to listen in, you’ll need some gear, but it looks very doable. The same page details several successful ham radio stations including those from [PY2SDR], [CD3NDC], [PY4ZBZ], [N6RFM], and many others. While the Dwingeloo telescope is a 25-meter dish, most of the stations have more conventional looking Yagi or helical antennas.

If your Mandarin is up to it, there is live telemetry on that page, too. You might have more luck with the pictures.

For working conventional satellites, you often need an agile antenna. We suspect the lunar orbiting satellite appears to move less, but you’ll have other problems with more noise and weak signals. Although hams have been bouncing signals off the moon for decades, they’ve only recently started bouncing them off airplanes.

36 thoughts on “Hams See Dark Side Of The Moon Without Pink Floyd

    1. You should also be concerned that a quantum leap is not actually a big change in position. A guinea pig isn’t really a pig either. Did you know that tin foil is made of aluminium? Do you perchance turn on or off any apparatus without a circular motion?

      Incidentally, the word of the day is:

          1. Copyright lawsuits are getting to be a joke these days, I’m going to mow the back field in a design next year then sue any of the satellite imagery/mapping websites that display it. ( see SMASH 137 vs gm)

  1. I think you mean the FAR side of the moon. Pink Floyd notwithstanding, the same side always faces away from Earth, whether it’s dark (as during a full moon) or bright (at the new moon).

  2. “Dark side of the moon” is a reference to the lack of knowledge rather than the lack of light, just like “Darkest Africa” wasn’t a reference to the skin tone of the inhabitants. Darkness has long been a metaphor for ignorance and light a metaphor for knowledge.

      1. Nothing wrong with it. Full Earth and the Moon is close to full or just past full. It’s not difficult to find a place in space where these are not self-negating. The camera just needs to be directly between the Earth and Sun for the Earth to be full, while the Moon is off this line just enough to get the not-quite-full look.

        1. Ya sure, but that Moon looks about as bright as an Earth-lit Moon. Or maybe that isn’t the Earth. It looks more like your basic hole-in-space, but caused by what? Usually an ion storm but sensors have suffered a flux reversal, so we will have to look out the window.

          1. It’s not an Earth-lit Moon. Why would you assume that? Since the Earth is much smaller, and we’re seeing the lit side of both, both are obviously being lit by the Sun.

            By the way – the only time you can really see an Earth-lit Moon is during a lunar eclipse, when the Sun is behind the Moon, putting the brightly-lit side of Earth shining on it. At all other times, there either isn’t enough of the Earth sunlit, or too much sunlight in the air to see the dim part of the Moon.

    1. China must have figured out to playcate on the Crown Dependencies laundering outfits and wasteful spending with “renditions” and graduate school detailed boring operations disclosures with plenty of loopholes, cliches, euphemisms, etc. I guess they’re like Senate Committee Hearings versus Judiciary Hearings that must have caught on in the U.S. at least with investors, shareholders, stakeholders… so NASA get’s less budget and other public stranger entities (well maybe not so strange compared to NASA-CIA post paperclip) get more budget… plus market capitalization and market value vitalization.

    1. SSDV (essentially packetised JPEG) over a 250bps GMSK channel. There is software out there to decode it but you’ll need a *very* large antenna to get enough signal to make it work.

    1. Awesome! I’ve been wanted to look at the schematics to see what the system is made of (just downloaded) and the feasibility of using even lower noise floor Burr-Brown ADC/DAC’s as well as look into what the chips are in the Rohde & Schwarz or other really low noise floor spectrum analyzers and hacking those into an SDR. There’s always a limiting components… though I wonder still what kind of hacked improvements exist with using different components even with an RTL-SDR under different STP.

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