Newton’s theory of universal
gravitation has had wonderful
success in explaining the
motions of the planets in our
Solar System, even leading to the discovery of Neptune. However, given the known planets in our Solar System, Newton’s theory does not fully explain the precession of Mercury’s orbit.
Some astronomers theorize that another planet, inside the orbit of Mercury, could account for the odd behavior of Mercury. This position is bolstered by the success in finding Neptune using the perturbations of Uranus’ orbit to calculate an orbit of the undiscovered planet. The proposed planet between the Sun and Mercury has been named Vulcan but has yet to be observe
What SPF sunblock should I bring if I visit Vulcan?