1821 - Alexis Bouvard detects
irregularities in the orbit
of Uranus
1825 - Pierre Laplace completes
his study of gravitation,
the stability of the solar system, tides, the precession of the equinoxes,
the libration of
the Moon, and Saturn's rings in Mecanique Celeste
1843 - John
Adams predicts the existence and location of Neptune
from irregularities in the orbit of Uranus
1846 - Urbain
Le Verrier predicts the existence and location of Neptune from irregularities
in the orbit of Uranus
1849 - Edouard Roche finds
the limiting radius of tidal
destruction and tidal creation for a body held together only by its self gravity,
called the Roche
limit, and uses it to explain why Saturn's rings do not condense into
a satellite
1856 - James
Clerk Maxwell demonstrates that a solid ring around Saturn would be torn
apart by gravitational forces and argues that Saturn's rings consist of a
multitude of tiny satellites
1866 - Giovanni
Schiaparelli realizes that meteor
streams occur when the Earth passes through the orbit of a comet that has
left debris along its path
1978 - Peter Goldreich
and Scott Tremaine present a Boltzmann equation model of planetary-ring dynamics
for indestructible spherical ring particles that do not self-gravitate and
find a stability requirement relation between ring optical depth and particle
normal restitution coefficient
1988 - Martin Duncan, Thomas
Quinn, and Scott Tremaine demonstrate that short-period comets come primarily
from the Kuiper Belt and not the Oort cloud
