Naked Science Forum

On the Lighter Side => New Theories => Topic started by: talanum1 on 18/02/2022 15:23:32

Title: How did Trappist-1 Form?
Post by: talanum1 on 18/02/2022 15:23:32

All of Trappist-1's seven planets orbits in a 3:2 ratio. How did that happen by chance?

Title: Re: How did Trappist-1 Form?
Post by: Origin on 18/02/2022 17:03:23

Quote from: talanum1 on 18/02/2022 15:23:32

All of Trappist-1's seven planets orbits in a 3:2 ratio.

They don't.

Title: Re: How did Trappist-1 Form?
Post by: evan_au on 19/02/2022 07:15:13

There are orbital patterns of two objects which are stable.
- There are some specific orbital patterns of 3 objects which are stable (eg Lagrange Points L4 & L5)
- But in general, any gravitational system or 3 or more objects has no closed-form mathematical solution, and must be modelled numerically.
- All the orbiting planets continually exchange momentum between them. At some points in time, this momentum becomes large enough to force one or more objects out of their orbits - perhaps changing places, or one expelled from orbit while the other orbit becomes very elliptical.
- Some orbits are particularly unstable - such as a 2:1 ratio, as the planets attract each other when they are the same point on every orbit.
- The orbits in our Solar System are semi-stable, which have been modeled out to 100 million years (ignoring outside influences)

Even if Trappist started with 3:2 orbital periods, they would not stay that way forever.

See: https://en.wikipedia.org/wiki/TRAPPIST-1