>>7309656 (lb)

>The expanding Earth?

"Gravity" is not relative to size, but rather to charge.

Everything is Electric!

http://www.everythingselectric.com/electric-gravity/

>>7309653 (lb)

>Or a lesser magnetisim…

Different Electromagnetic environment, because at the time we were orbiting a red dwarf star, we now know as the planet Saturn. Also, there's a decent chance that our planet was tidally locked in this early configuration, similar to the way that our Moon is orbiting Earth.