[MtnClimber]

I know that gravity interactions can cause predictions of what is causing the interaction. But, as far as I know, only the Cassini space probe gravity interactions indicate the presence, which may be there. The planetary orbits do not indicate it yet as far as I understand. The 26 million year extinction cycle has caused theories that an outer eccentric orbiting planet, not yet discovered, is disrupting orbits of outer comets that sometimes collide with earth. It could be, but there could be other explanations.

Our solar system is not in the central disk of the Milky Way, but swings back and forth across the dense central disk roughly every 30 million years. I have been looking to see if there is correlation with galactic plane crossings and mass extinctions. So far no luck, but 30 million years and 26 million years may be measurement error, but is far too long for the orbit of a planet. There could be a 9th planet and they are looking with much better equipment. I am just not convinced there is enough evidence to say more than it could be.

[JimSEA]

Nor am I certainly but the informed speculation is fun to follow.

[Vermont Lt]

I agree. I got lost in calculus. There is no way I could understand how to calculate the elliptical orbit of anything.

I just think it’s fascinating that very small changes in the track of tiny space vehicles could be measured in a way that tells “something” is out there.

We will be old and gray by the time they figure this out. (Old and gray is not a huge leap for me.)