How many planets?
by John Swanson

Copyright 2016 Puzzles with a Purpose. All rights reserved.

According to established theory, no new planets have formed in the Solar System for the past 4.6 billion (or so) years. Yet, over the past couple of millennia man's knowledge and definitions have resulted in changes to the number of solar objects called planets.

Planets in the Solar System
 

Using concepts of the period, how many planets were there and what were their names in each of the following years (CE): 

Year

Number

Names of the Planets

0150

 

 

1700

 

 

1781

 

 

1851

 

 

1854

 

 

1930

 

 

2006

 

 

2016

 

 

Take ten points for every correct answer and an additional point for the name of each solar object you can name that has been deemed a planet.

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