What is a light-day? The milestone Voyager 1 is closing in on

(science.nasa.gov)

40 points | by geox 2 hours ago

7 comments

  • polalavik 1 hour ago
    Free space pathloss for rf signals is proportional to 1/r^2, absolutely bonkers we can get anything from voyager.
    • rnhmjoj 53 minutes ago
      1/r² is for an isotropic radiator, but Voyager 1 mounts (thankfully) a high gain directional antenna. The gains seem to be 36dBi or 48dBi, depending on the frequency [1]. This means that when pointed towards Earth, the signal power is actually between 4000 to 63000 times stronger than what that formula would give you. It's still tiny, but not as bad as that would suggest.

      [1]: https://space.stackexchange.com/questions/65801/what-are-the...

      • robotresearcher 41 minutes ago
        For clarity, it’s still proportional to 1/r², but with a much larger multiplier than one.
    • freedomben 1 hour ago
      And with 50 year old tech! I do wonder if humanity will get to a point where we can retrieve the spacecraft at some point in the future (cue Star Trek fantasies)
      • bonzini 1 hour ago
        Technically, the receivers need not use 50 years old tech. I am saying that not to be annoying but because I wonder how much that matters.
      • deadnomore 49 minutes ago
        I would prefer they just maintain it as long as possible and maybe deploy a proxy for earth that trails behind it indefinitely once it’s finally out of range. Let’s set an unbreakable record.
  • zomtorg 1 hour ago
    And the closest known galaxy to the Milky Way, Canis Major Dwarf Galaxy, is just 25,000 light-years away - it's almost incomprehensible how vast the universe is!
    • seydor 0 minutes ago
      Yeah the only space tech worth pursuing is Wormholes
  • robotresearcher 52 minutes ago
    > the spacecraft, in flight since 1977, is cruising at nearly 38,000 mph (61,000 kph) through the vacuum of space,

    The page takes great pains to explain things, but omits a frame of reference for this speed. I’m guessing it’s sun-relative, but it could be relative to its take-off on Earth. Does anyone know?

  • decoydave 15 minutes ago
    So glad voyager has real stuff on it for aliens to see rather than the crap that’s put out today by those with an agenda
  • soniman 1 hour ago
    So it is traveling 1/18250 the speed of light. That is pretty fast.
  • cineticdaffodil 14 minutes ago
    [dead]
  • lunargamma676 41 minutes ago
    [flagged]