What planet comes first?

Answer 1

== == Most of the time the answer would be Neptune. But for about 15 years of Pluto's orbit, it is inside Neptune's orbit, so during those times the answer would be Uranus. Pluto is currently beyond Neptune's orbit.

Answer 2

The closest planet to Pluto would be Neptune. Note that Pluto was famously reclassified as a dwarf planet (which is defined as neither a planet nor a satellite); and also was once considered (and rejected) as a candidate twin-planet system with its moon Charon owing to the latter's relatively large mass.

Because of the shape of Pluto's orbit it does occasionally come inside that of Neptune.

Answer 3

Pluto was discovered after all the planets (in the Solar system) had been discovered. One or possibly two minor planets were discovered before Pluto, but the majority of minor planets and minor planet candidates were discovered afterward.

Answer 4

Although Pluto is not a planet, rather a dwarf planet, the answer you are looking for is neptune.

Answer 5

The cavemen did, once the weather cleared up.

Answer 6

which of eight planets is alphabetically first

Answer 7

Mercury