Ocean Tides

[PlutonianEmpire]

For the following planet/moon system, how high would the tides be assuming the planet is reasonably Earthlike?

Code: Select all

"Planet" "ALF Cen B" {
   Radius 7672.6753
   Mass 2
   EllipticalOrbit {
      Period            0.63572895277207392197125256673511
      SemiMajorAxis     0.7160
      Eccentricity      0.0127
      Inclination       82.7292
      AscendingNode     68.1276
      ArgOfPericenter   2.3746
      MeanAnomaly       286.4439
   }

   RotationPeriod          26.0431
   EquatorAscendingNode   67.4408
   Obliquity               94.6252
}

"Moon1" "ALF Cen B/Planet" {
   Radius 1306.2126
   EllipticalOrbit {
      Period            3.4583
      SemiMajorAxis     121747
      Eccentricity      0.0153
      Inclination       4.0750
      AscendingNode     185.0341
               ArgOfPericenter   88.7125
      MeanAnomaly       44.4596
   }
   Obliquity        4.0750
   EquatorAscendingNode 185.0341
   RotationOffset   174.200
}

"Moon2" "ALF Cen B/Planet" {
   Radius 2250.4222
   EllipticalOrbit {
      Period            22.9467
      SemiMajorAxis     402782
      Eccentricity      0.0139
      Inclination       7.4258
      AscendingNode     211.0696
                ArgOfPericenter   249.2957
      MeanAnomaly       190.2397
   }
   Obliquity 7.4258
   EquatorAscendingNode 211.0696
   RotationOffset 194.200
}

[radtech]

As a first approximation, the mid-ocean tides raised on this planet range from a minimum of 48.8 cm to a maximum of 81.4 cm. This tidal range, unlike on Earth, is dominated by stellar gravitation rather than the gravitational effect of its satellite(s). The smaller satellite (Moon-1) contributes a maximum of 2.7 cm to the mid-ocean tide, Moon-2 contributes a maximum of 29.9 cm to the mid-ocean tide, while the stellar primary contributes 48.8 cm to the total. This presumes that the stellar primary is essentially identical to Sol and that the densities of the two satellites are identical to that of Luna. The actual mid-ocean tide height for any given time depends on the orbital dynamics of the star-planet-satellite(s) system.

As is the case with all things, your mileage may vary,

Radtech

[PlutonianEmpire]

For reference, how much is Earth's tides?

Also, the planet is orbiting Alpha Centauri B, not Alpha Centauri A, as your post seems to imply.

[radtech]

For reference, how much is Earth's tides?

Also, the planet is orbiting Alpha Centauri B, not Alpha Centauri A, as your post seems to imply.

You are, of course, correct in your observation that I assumed a Sol-like star (a result of late-night mis-reading).

For reference, the mid-ocean tides on Earth are 54 cm for those caused by Luna and 25 cm for those caused by Sol.

For Alpha Centauri B, the tides raised by the star are 43.9 cm at periastron and 41.7 cm at apastron. The satellite-induced mid-ocean tides were calculated for their semi-major axes, and so do not reflect their closest and most distant approaches to the planet (though neither has an eccentricity that would significantly change their respective tide heights, IMHO).

Sorry for the mix-up.

Radtech

[PlutonianEmpire]

It's okay.

Thank you for your help.