Letter Re: Question About Eris (Planet X) Tidal Forces

Dear JWR,  
I will present some facts and allow you to draw your own conclusions.  Having been in Army Intelligence, I am certain that you are capable of analyzing data and arriving at multiple possible scenarios of likely outcomes:

1.)     There are currently 9 [well-known] planets in our solar system;
2.)     According to physicists, objects of greater mass attract objects of lesser mass (same goes for planets);
3.)    On October 31, 2003 a new , 10th planet (Planet X [also known as Eris]), was discovered outside our solar system, but traveling towards it in an elliptical orbit;
4.)    See this NASA web page.
5.)    At first this discovery was heralded with much publicity, then died down… this in itself may mean nothing.
6.)     As our own Moon affects tides and weather on Earth, imagine how disruptive a large mass like another planet traveling close to Earth would become;
7.)    Some people say that the extremes we are currently experiencing in weather and seismic activity is actually a felt influence of Planet X as it currently approaches a closer orbit to Earth.

[some deleted, for brevity.]

Sincerely, Wayne.

JWR Replies: The orbit of Pluto takes 248 years.  Eris (aka 2003 UB313, also aka “Planet X”) is indeed part of our solar system. But it is in a much more distant orbit than Pluto. Its tracked orbital path shows it coming no closer to Earth than the average orbital distance of Neptune. It also has an orbital velocity that is slower than Pluto’s. From what I’ve read in credible sources, there is no evidence that it will ever get near Earth.

As for gravitational perturbations (tidal forces), even when the much-vaunted Grand Alignment took place on May 5, 2000, the tidal effect was so small that it had five or six zeros in front of it. The inverse square law also applies to gravitational forces over the vast orbital distances of planetary space. The gravitational forces exerted by Eris are less than 1/1000th than that of Jupiter, and even those are negligible, here on Earth.

I don’t see any cause for alarm about Planet Eris, even for our great-great grandchildren. It is those large, but as yet un-detected Earth crossing asteroids that worry me.