{
  "export": {
    "source": "https://urth.darkrealm.vip/thread/urth/3102",
    "note": "Exported from an unofficial mirror of a public mailing list. Copyright in each message remains with the person who wrote it.  Email addresses are obscured as `user at host`, the form the original archive published. This file was rebuilt from parsed fields rather than retained headers, so it is faithful in content but not byte-exact.",
    "addresses": "obscured as 'user at host'"
  },
  "archive": "urth",
  "thread": {
    "id": 3102,
    "subject": "Green as being in a transfer orbit",
    "messages": 1,
    "voices": 1,
    "first": "2002-03-29T03:56:50+00:00",
    "last": "2002-03-29T03:56:50+00:00"
  },
  "messages": [
    {
      "message_id": "<urth-v0203-502@digest.urth.net>",
      "from": {
        "name": "Michael Andre-Driussi",
        "address": "mantis at siriusfiction.com"
      },
      "date": "2002-03-29T03:56:50+00:00",
      "subject": "(urth) Green as being in a transfer orbit",
      "in_reply_to": null,
      "reply_link": null,
      "blocks": [
        {
          "kind": "text",
          "depth": 0,
          "text": "Further possibilities flowing from the notion of Green being in an outer\norbit relative to Blue.\n\nA six year planetary orbit in our solar system would be somewhere in the\nregion of our asteroid belt.\n\nWhat we are looking for would be a \"cometary\" orbit, and since I just\nmentioned the asteroid belt, there are two groups of \"earth crossing\"\nasteroids (Apollo and Amor) which do something like that.  But we don't\nwant Green to \"cross\" Blue (like a comet or an AA asteroid), rather we want\nit to come awful close and then back off.  Oscillate.\n\nThis sounds exactly like a transfer orbit.  A Hohmann Orbit.\n\nUsing a permanent habitat on a non-stop Earth/Mars Hohmann Orbit, the\nhabitat (like Skylab, or an asteroid: any non-ship nudged into the orbit)\nwould cycle between planets, 2 years one way.  Which means it would be 4\nyears before the habitat returned to Earth.  Note that this is \"unpowered\"\ndrift--no titanic spacedrives needed, once the orbit is established.\n\nThat looks incredibly close compared to what we've been looking at before!\n\nThe HO =does= require the presence of another planet in the Breen system,\ntaking the place of Mars in the example above.  It should be a terrestrial\nplanet, like Mars, rather than a Jovian (? maybe I'm too fretful of it\nbeing captured by the greater gravity of a jovian?).  If terrestrial, it\nmight have such low albedo as to be nearly invisible to the naked eye\n(hmmm, I'll have to think on that).  It should be further away from the\nprimary star than Mars is, so that a one-way transfer will last 3 years,\nand thus a 6 year lapse between Blue/Green encounters.\n\nHohmann Orbit to Jupiter is 2.7 years one way.  Hey now!  So close to what\nwe are looking for that it is stupifying!\n\nGranted, if Green wanders out past the orbit of Jupiter to planet \"Zeus\" it\nis going outside of the habitability zone and should suffer a ragnarok-like\nwinter.  But only for the time it is out there!  Is there suggestion in the\ntext about seasons of any kind on Green?\n\nBut that is all just another issue.  The question of Green's orbit may be\nsolved.\n\n=mantis="
        }
      ]
    }
  ]
}