4 ms·

Regular shuttles for interplanetary travel timed with periodically favorable orbital positions?

deleted 10y ago
[deleted]
tajen 10y ago
At that distance, gravity must be really fun. Tides are not only for water, such tides can also change the height of mountains, the balance of high-rise buildings, infer on volleyball rules, make you fart because of changes in atmospheric pressure, or... be leveraged to generate electricity. Those guys have simili-infinite energy at human scale.
- gydfi 10y ago
  Would they? I mean, we can see geological features on our moon, and our tides are orders of magnitude away from being rock-tearing events. I mean, the moon is small, but... how close do these planets approach, anyway?
  - rosser 10y ago
    Close enough that the perturbations these planets induced in one another's orbits allowed the team to estimate their masses at between 0.4 and 1.4 Earth-masses. In astronomical terms, that's very close.
  - ccozan 10y ago
    So it possible to see Avatar like suspended rocks ? Somewhat orbiting some lagrangian point, which is very close to surface.
    - ConceptJunkie 10y ago
      The Moon is about 2% of Earth's mass, not 27%.
  - scardine 10y ago
    The moon is not that small, it is 27% of earth's size. Any other satellite in the solar system is way smaller compared to the planet they orbit. I dare to say that earth and moon are twin planets instead of a planet and a satellite.
    - Mtinie 10y ago
      @ConceptJunkie > The Moon is about 2% of Earth's mass, not 27%. 2% of mass, yes, but also 27% of the diameter. You are both right.
      - mirimir 10y ago
        My first reaction was WTF? Then 0.27^3 = 0.0197 And then, only 60% as dense (no core) so 0.0119 :)
        saalweachter 10y ago
        One of my scale numbers is, everything between Jupiter and the Sun masses less than 2 Earths -- Venus, Mars, Mercury, the Moon, and all the asteroids mass less than the Earth. And only just barely! You get to around 99% of the Earth's mass with the rest of the inner solar system. All of the other rocky bodies in the solar system give you another 10% of Earth's mass out to Pluto and another 10% beyond.
        mirimir 10y ago
        You just blew my mind ;) What do we know about the gas giants' cores?
        saalweachter 10y ago
        Gas giant cores are weird. Based on models of solar system formation, we're like, pretty sure they started with rocky (or icy) cores that were dozens of times bigger than Earth. But we're not sure they're still there. Due to the intense conditions inside a gas giant, we're not sure if they still have a rocky core, or if the cores have liquified or even convected away to mix with the gasses. So the answer could be "there are dozens of times the Earth's mass worth of rocky material inside gas giants" or "there is no rocky material inside gas giants", or anywhere in-between. We need more detailed study of the gas giants before we can answer that question. Models of solar system formation also suggest the Kuiper belt started with dozens of times Earth's mass, but we only see about 10% there now, and we only have pretty good guesses about what happened. (I mean, it almost certainly got ejected, but the "why" is harder.)

deleted 10y ago

[deleted]

tajen 10y ago

At that distance, gravity must be really fun. Tides are not only for water, such tides can also change the height of mountains, the balance of high-rise buildings, infer on volleyball rules, make you fart because of changes in atmospheric pressure, or... be leveraged to generate electricity. Those guys have simili-infinite energy at human scale.

gydfi 10y ago
Would they? I mean, we can see geological features on our moon, and our tides are orders of magnitude away from being rock-tearing events. I mean, the moon is small, but... how close do these planets approach, anyway?
- rosser 10y ago
  Close enough that the perturbations these planets induced in one another's orbits allowed the team to estimate their masses at between 0.4 and 1.4 Earth-masses. In astronomical terms, that's very close.
- ccozan 10y ago
  So it possible to see Avatar like suspended rocks ? Somewhat orbiting some lagrangian point, which is very close to surface.
  - ConceptJunkie 10y ago
    The Moon is about 2% of Earth's mass, not 27%.
- scardine 10y ago
  The moon is not that small, it is 27% of earth's size. Any other satellite in the solar system is way smaller compared to the planet they orbit. I dare to say that earth and moon are twin planets instead of a planet and a satellite.
  - Mtinie 10y ago
    @ConceptJunkie > The Moon is about 2% of Earth's mass, not 27%. 2% of mass, yes, but also 27% of the diameter. You are both right.
    - mirimir 10y ago
      My first reaction was WTF? Then 0.27^3 = 0.0197 And then, only 60% as dense (no core) so 0.0119 :)
      - saalweachter 10y ago
        One of my scale numbers is, everything between Jupiter and the Sun masses less than 2 Earths -- Venus, Mars, Mercury, the Moon, and all the asteroids mass less than the Earth. And only just barely! You get to around 99% of the Earth's mass with the rest of the inner solar system. All of the other rocky bodies in the solar system give you another 10% of Earth's mass out to Pluto and another 10% beyond.
        mirimir 10y ago
        You just blew my mind ;) What do we know about the gas giants' cores?
        saalweachter 10y ago
        Gas giant cores are weird. Based on models of solar system formation, we're like, pretty sure they started with rocky (or icy) cores that were dozens of times bigger than Earth. But we're not sure they're still there. Due to the intense conditions inside a gas giant, we're not sure if they still have a rocky core, or if the cores have liquified or even convected away to mix with the gasses. So the answer could be "there are dozens of times the Earth's mass worth of rocky material inside gas giants" or "there is no rocky material inside gas giants", or anywhere in-between. We need more detailed study of the gas giants before we can answer that question. Models of solar system formation also suggest the Kuiper belt started with dozens of times Earth's mass, but we only see about 10% there now, and we only have pretty good guesses about what happened. (I mean, it almost certainly got ejected, but the "why" is harder.)