Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: neilep on 02/08/2020 13:07:12
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Dearest Orbitoloigists,
Planets are my all time favourite thing to live on. Planets are great !
Our Galaxy, the Soya Milky Bypass...is quite the symmetrical is not it ?
Has it been noticed if the Exo Planets discovered are orbiting their suns in the same plane as our solar system ? Is there a galaxial symmetry in play here ?
whajafink ?
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Even our own Solar System doesn't lie on a single plane. Pluto is an outlier (with an orbital inclination of 17.16 degrees), and Eris even more so (44.04 degrees). There are even minor bodies that come close to a 90 degree orbital inclination. The invariable plane of the Solar System itself is already at a tilt of about 60 degrees relative to the galactic plane of the Milky Way.
Exoplanets have variable orbital inclinations as well: https://en.wikipedia.org/wiki/List_of_nearest_exoplanets
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Effectively, the orbital plane of a given star system is random. They don't align with the galactic axis in general. Ours certainly doesn't as Kryptid points out.
In a single star system, all the planets that formed as part of that star system (not captured for instance) tend to orbit with a relatively common axis. Pluto didn't form in the same way as planets do, and is in fact a sort of displaced Oort object.
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Many of the exoplanets discovered to date (eg by the Kepler and TESS space missions) have been discovered by the transit method - a planet passes between the other star and us (the Earth and orbiting satellites).
- So the planetary plane of that star intersects us
- This means we can only discover about 1% of planetary systems by this method, as most planetary planes will not intersect us
Since these exoplanets have been found all over the sky, that implies that planetary disks lie in all possible orientations relative to whatever coordinate system you wish to choose (eg the galactic disk, the Solar system ecliptic, etc).
See: https://en.wikipedia.org/wiki/Transiting_Exoplanet_Survey_Satellite
https://en.wikipedia.org/wiki/Kepler_space_telescope