Geology Through Literature - Paradise Lost

The next up on my Geology Through Literature thread is Paradise Lost by John Milton published in 1667. You can get my complete thoughts on the book/story over at my other blog - The Remnant, but for here I will just go into the geological or basic scientific aspects that are brought up in the story.

The geological content in the story is rather sparse but I did note one thing that I wanted to mention.

Book V

"Moon, that now meet'st the orient sun, now fly'st,With the fixed stars, fixed in their orb that flies; And ye five other wandering fires, that move In mystic dance not without song, resound His praise, who out of darkness called up light."

I highlighted this paragraph because the "five other wandering fires" refers to the five planets of the Solar System. That got me wondering, when were the planets discovered. If five planets (not including our own) were known by 1667, when did we know about them?

1st Planet Discovered - Earth. Year....duh.

2nd-6th Planets Discovered - Mars, Venus, Mercury, Jupiter, and Saturn can all be seen by the naked eye. So it is impossible to determine exactly when they were discovered but they were known since at least the 2nd century BC (Sachs, 1974).

7th Planet Discovered - Uranus - March 13, 1781. Discovered by William Hershel who realized that it was moving with respect to the stars (meaning that it did not move with the stars. It was doing it's own thing).

8th Planet Discovered - Neptune - September 18, 1846. Discovered by Johann Galle and Heinrich Louis d'Arrest based on predictions by Urbain Le Verrier. Le Verrier predicted there must be another planet further out due to the eccentric orbit of Uranus.

9th Planet Discovered - Pluto - February 18, 1930. Discovered by Clyde Tombaugh who used eccentricities in Neptune's orbit to predict the presence and location of Pluto. It is now known that the "eccentricities" were actually just measurement errors and Tombaugh got lucky.

9th Planet Rescinded - Pluto - August 24, 2006
    - Due to the redefinition of what a planet actually is, Pluto's planetary status was revoked. You can read more about it here: Space.com

Through most of history our reliance on the stars for navigation and even for light during the evenings had provided us with the knowledge of 6 of the planets in our Solar System. Only two (based on the current definition of a planet) remained to be discovered.

References
http://curious.astro.cornell.edu/about-us/56-our-solar-system/planets-and-dwarf-planets/general-questions/222-who-discovered-each-planet-intermediate
http://www-groups.dcs.st-and.ac.uk/~history/HistTopics/Neptune_and_Pluto.html
http://www.space.com/43-pluto-the-ninth-planet-that-was-a-dwarf.html
http://www.jstor.org/stable/74273?seq=1#page_scan_tab_contents

In the News - Bring Pluto Back!!!!

The IAU (International Astronomical Union) has officially demoted Pluto to a new class: the Dwarf Planet. This means that under the classical definition of planet ratified at the meeting there are only 8 classical planets.

I am at odds about this. I say we start a petition to bring Pluto back. Anyone with me, comment on this blog and we will get this overruled. Come on people Pluto was not just any planet for most of you. It was your inner rouge.

This is not the usual planet, like Mars or Jupiter, that could go in any old elliptical orbit like all the others, but this was an eccentric planet. Willing to take risks. To think outside the box. To become the 8th planet at times and not always the 9th. What other planet can boast that. NONE I tell you, none. What planet could live in the realm of gaseous planets and still not be considered one of them, none other than our beloved Pluto. And now they go and try to take that away from us.

From this moment on, I am on strike of the planetary system set up by the world. Strike I tell you. STRIKE!!!!

Article Here

And note: The definition of a dwarf planet states that the dwarf planet "has not cleared the neighborhood around its orbit, and is not a satellite."