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4 votes
Accepted

Are the rotational axes of Earth and Mars parallel?

The polar axis of Mars is not parallel to the polar axis of Earth. The north celestial pole of Earth has a declination of 90°, but the north celestial pole of Mars has a declination of almost 53°. ...
PM 2Ring's user avatar
  • 15k
4 votes

Does the inclination of an orbital plane change due to pull from other orbiting objects?

If a ring of material forms in a plane inclined to the mean plane of a planet's system, forces could act to pull it toward the mean plane, initially causing precession. These forces arise from the ...
eshaya's user avatar
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3 votes
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Orbit equation solver giving wrong orbits

MAJOR EDIT! Upon further inspection, it appears the actual issue is that the axes of the rotation matrix are incorrect. Swapping r_z and r_y in the ...
Eduardo Dieppa's user avatar
3 votes

Why is rate of apsidal precession not consistent with the first time derivative of the argument of periapsis

Turns out I completely missed the fact that the linked paper, when giving values for $\Omega$ etc, is not taking the reference plane as the sun’s equatorial plane or the solar system’s invariable ...
anonymous's user avatar
  • 121
3 votes
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Is it possible to determine orbit orientation of exoplanet without direct imaging and astrometry?

Yesish. The transit method joined with radial velocity measurements can give quite tight constraints on the inclination of the orbits with respect to our line of sight as well as their eccentricity ...
planetmaker's user avatar
3 votes

Has the inclination of the orbital plane of Phobos and Deimos followed that of Mars' axial tilt?

Back in 1965, Peter Goldreich published a short and elegant paper addressing the orbital evolution of a satellite of a uniformly precessing oblate planet. Goldreich demonstrated that, assuming the ...
Michael_1812's user avatar
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3 votes
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Which star system has the highest multiplicity (# of stars), whose orbits are known for all stars?

As of writing this, 11 October 2023, I am reasonably certain that the star systems with the highest multiplicity, whose orbital periods of each of the stars are known, are those of the two septuple ...
Curious Layman's user avatar
2 votes

What are "non-Keplerian" orbits? What are some familiar examples in our solar system, and can some still be closed?

What exactly are "non-Keplerian" orbits? Let's first start with Keplerian orbits. A Keplerian orbit is the motion of one body relative to another body, and takes the form of an ellipse, ...
DialFrost's user avatar
  • 2,115
2 votes

Calculating Ephemeris from JPL Osculating Element

In the osculating elements for 2023-12-24, the period of 1.9513×108 seconds is 6.183 years, or 71 days shorter than the 6.378 year period in the elements for 2014-03-31. An encounter with Jupiter, 0....
Mike G's user avatar
  • 18.7k
1 vote
Accepted

Does the inclination of an orbital plane change due to pull from other orbiting objects?

Per @eshaya's comment: Tidal dissipation from precessional forces brings orbiting objects into the lowest energy orbital plane
uhoh's user avatar
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1 vote
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Can there be multiple periapsides?

In the picture, and in any two-body orbit, the stars are closest together at a single periapse, and there is a single line of apsides. In the picture, the stars are closest together when they are ...
James K's user avatar
  • 126k
1 vote
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What is the duration of a year on the Moon (Tropical/Sidereal period) for orbit about the Sun ? How/why does length of lunar days vary ? Soltices?

A day on the moon lasts 29.53 days (a synodic month), slowing down by 0.005 seconds every century. ref. The tilt of 1.54' relative to the Sun has an 18.5996 years periodicity. ref.
bandybabboon's user avatar
  • 4,268

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