1. C.M. Rodrigue, 2016 Geography, CSULB Mars: History of Exploration I Geography 441/541 Geography of Mars S/16 Dr. Christine M. Rodrigue

2. C.M. Rodrigue, 2016 Geography, CSULB Mars: History of Mars Exploration  History of Earth-based Mars exploration  The eyeball era  Ancient astronomer/astrologers noticed that five stars wandered: astra planeta  Mercury  Venus  Mars  Jupiter  Saturn

3. C.M. Rodrigue, 2016 Geography, CSULB Mars: History of Mars Exploration  History of Earth-based Mars exploration  The eyeball era  Indians described a Mars retrogation in 3,010 BCE

4. C.M. Rodrigue, 2016 Geography, CSULB Mars: History of Mars Exploration  History of Earth-based Mars exploration  The eyeball era  Chaldean database:  Enuma Anu Enlil, which dates back to 652 BCE and continued until 60 BCE.  Sample entry: "That month, the equivalent for 1 shekel of silver was: barley [something missing] kur; mustard, 3 kur... At that time, Jupiter was in Scorpio; Venus was in Leo, at the end of the month in Virgo; Saturn was in Pisces; Mercury and Mars, which had set, were not visible."

5. C.M. Rodrigue, 2016 Geography, CSULB Mars: History of Mars Exploration  History of Earth-based Mars exploration  The eyeball era  Chaldean database:  Enuma Anu Enlil, which dates back to 652 BCE and continued until 60 BCE.  Sample entry: "That month, the equivalent for 1 shekel of silver was: barley [something missing] kur; mustard, 3 kur... At that time, Jupiter was in Scorpio; Venus was in Leo, at the end of the month in Virgo; Saturn was in Pisces; Mercury and Mars, which had set, were not visible."

6. C.M. Rodrigue, 2016 Geography, CSULB Mars: History of Mars Exploration  History of Earth-based Mars exploration  The eyeball era  Chinese dynastic historians  Interested in planetary conjunctions, including those involving Mars  Trying to correlate with events on Earth  These records go back to the fourth century BCE

7. C.M. Rodrigue, 2016 Geography, CSULB Mars: History of Mars Exploration  History of Earth-based Mars exploration  The eyeball era  Mayans developed elaborate calendars  Date back from 1800 BCE to the time of Columbus  Heyday was from 250 to 900 CE  Spanish destroyed most of their written records but a few of the priestly codices or handbooks survive  The Dresden Codex includes a "Mars Beast Table" that predicts Mars' motions and retrogations

8. C.M. Rodrigue, 2016 Geography, CSULB Mars: History of Mars Exploration  History of Earth-based Mars exploration  The eyeball era  Ancient Greeks really bugged by retrogations  Here’s one for Mars for June through November 2003

9. C.M. Rodrigue, 2016 Geography, CSULB Mars: History of Mars Exploration  History of Earth-based Mars exploration  The eyeball era  Ancient Greeks try to process the behavior of the planets:  Aristotle (~384-322 BCE) saw an occultation of Mars by the Moon and figured out Mars had to be farther from Earth than the Moon  Aristarchus (~310-230 BCE) developed heliocentric theory of the solar system and that the fixed stars had to be really, really far away  Hipparchus (~190-120 BCE) described the five planets' orbits as "deferents" around the earth  Ptolemy (~90 – 168 CE) added epicycles to handle retrogations  The collapse of Græco-Roman civilization in the fifth century CE put an end to work on Mars or any other science for a long time: The Dark Ages

10. C.M. Rodrigue, 2016 Geography, CSULB Mars: History of Mars Exploration  History of Earth-based Mars exploration  The eyeball era  Ptolemy’s epicycles

11. C.M. Rodrigue, 2016 Geography, CSULB Mars: History of Mars Exploration  History of Earth-based Mars exploration  The eyeball era  Rise of Islam in the 7 th century CE rejuvenated Arab culture and work on math and science  Greek and Roman classics were revived and extended  Indian and Persian work on the modern numeric system was adapted by the Arabs: Arabic numerals  Algebra was elaborated (al-Jabr)  Ibn al-Haytham around the 10th century and Nasir ad-Din at-Tusi in the late 13th century revised Ptolemy’s epicycle system to make it better able to handle Mars’ and other planets’ retrogations  These developments brought to Europe, partly due to the Crusades

12. C.M. Rodrigue, 2016 Geography, CSULB Mars: History of Mars Exploration  History of Earth-based Mars exploration  The eyeball era  Europeans, inspired by rediscovery of the classics and the writings of the Arab scientists got into the swing of empirical science, too  Copernicus in 1543 revives Aristarchus’ heliocentrism:  Earth rotates around a N/S axis  It and the OTHER 5 planets revolve around the Sun in perfect circles  He had to keep Ptolemy’s epicycles to account for retrogations  Tycho Brahe (1546 to 1601), instrument engineer and disciplined observer of the night skies, created databases of his team’s observations and focussed a lot on Mars due to its difficult pattern of motion

13. C.M. Rodrigue, 2016 Geography, CSULB Mars: History of Mars Exploration  History of Earth-based Mars exploration  The eyeball era  Johannes Kepler  Went to study with Tycho Brahe and they began to fight: Kepler was intrigued by Copernicus’ heliocentric theory and Brahe thought it was nuts  Brahe withheld his database from Kepler as a result, only letting him see the Mars data, which he thought was so difficult that it would keep Kepler out of trouble  Kepler found that the best way to make sense of Mars' orbit was to apply Copernicus' heliocentric theory but relax the assumption about a perfectly circular orbit  There’s speculation that he might actually have offed Brahe in 1601 to get his data!  He published his three laws of planetary motion in 1609

14. C.M. Rodrigue, 2016 Geography, CSULB Mars: History of Mars Exploration  History of Earth-based Mars exploration  The eyeball era  Kepler’s First Law of Planetary Motion: Planetary orbits are ellipses, not circles, with the Sun at one of the two foci of each ellipse

15. C.M. Rodrigue, 2016 Geography, CSULB Mars: History of Mars Exploration  History of Earth-based Mars exploration  The eyeball era  Kepler’s Second Law of Planetary Motion: The line connecting the planet to the Sun sweeps out equal areas in equal times

16. C.M. Rodrigue, 2016 Geography, CSULB Mars: History of Mars Exploration  History of Earth-based Mars exploration  The eyeball era  Kepler’s Third Law of Planetary Motion: The ratio of the squares of two planets’ revolutionary periods is the same as the cubes of their semi-major axes. The period a planet requires to go around the Sun increases rapidly with the radius of its orbit.