Regions

Sun

Mercury

-orbit procession 93% accounted for by Newton's laws of motion but other 7% are not
-quest to explain this
-investigation begins immediately after discovery of Janus, assumed irregularities explain there is another planet
-so many attempts to discover this planet fail, but people cannot give up because everything about Newtonian mechanics
-attempts to correct it, increasingly literal
-quest only ends with Invariance > Liang's theory of gravity

Venus

Earth

Moon

Mars

Inner Asteroid Belt

Jupiter

Saturn

Uranus

Janus

-theorized based on irregularities in Uranus' orbit
-Von Lamont observes eighth planet in 1845, and he is able to determine by motion that it is a planet
-discovery verified by other astronomers, celestial mechanics
-named Janus in reference to how it was theorized before being observed, effectively two-faced in its discovery

Outer Asteroid Belt

-no Lowell type obsessed with searching for ninth planet
-Tyche [Pluto] discovered instead in 1951 with mass < 0.1 Earth, which seems way too small, controversy over whether it is ninth planet
-some textbooks include it, but in general in heavy dispute, and so not
-further searching happens, discover Idyia [Eris] in 1957
-then Metis [Makemake], Telesto [Orcus], Klymene [Haumea], and Peitho [Quaoar]
-conclusion is that they are tip of iceberg of "outer asteroid belt", a thought which is proven