C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Exploration
Geography 494-01
S/07
Dr. Christine M. Rodrigue
C.M. Rodrigue, 2007Geography, 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
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The eyeball era
Indians described a Mars retrogation in 3,010 BCE
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The eyeball era
Chaldean database: Enuma Anu Enlil, which date 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."
C.M. Rodrigue, 2007Geography, 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
C.M. Rodrigue, 2007Geography, 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
C.M. Rodrigue, 2007Geography, 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
C.M. Rodrigue, 2007Geography, 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 Graeco-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
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The eyeball era
Ptolemy’s epicycles
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The eyeball era
Rise of Islam in the 7th century CE rejuvenated Arab culture and work on math and science
Greek and Roman classics were revived and extended Algebra and the Arabic numerals were developed 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
C.M. Rodrigue, 2007Geography, 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
C.M. Rodrigue, 2007Geography, 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 publishes his three laws of planetary motion in 1609
C.M. Rodrigue, 2007Geography, 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
C.M. Rodrigue, 2007Geography, 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
C.M. Rodrigue, 2007Geography, 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 semimajor axes. The period a planet requires to go around the Sun increases rapidly with the radius of its orbit.
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The telescope era
Galileo Galilei (1564-1642) In 1609, he builds and begins using a telescope He observed Mars in order to test Copernicus’ and
Kepler’s predictions that the planets should show phases His telescope was too primitive, so he honestly reported
he couldn’t see Martian phases but that Mars didn’t look perfectly round
For his defense of Copernicus' heliocentric theory against specific orders of the Church, Galileo got into trouble with the Inquisition and was ordered into prison, a sentence later commuted to lifelong house arrest.
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The telescope era
Francisco Fontana, Italian astronomer, uses a telescope to observe Mars in 1636
He can clearly see that Mars was in gibbous phase, as Copernicus, Kepler, and Galileo expected
He makes the first drawings of Mars, in full and gibbous phases
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The telescope era
Christiaan Huygens in 1659 got such a good look at Mars:
He sees it rotates around a N/S axis
He figures its day length is very much like Earth’s
He left a few sketches
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The telescope era
Jean Dominique Cassini observes bright spots at the poles and dark spots along the equator in the 1660s
In 1672, he and a friend simultaneously observe Mars from different places on Earth and he uses parallax to figure Mars’ distance from Earth
Applying Kepler’s 3rd law, he uses this Mars distance to figure out how far Earth was from the Sun
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The telescope era
In 1719, Giacomo Maraldi (Cassini’s nephew), notes changes in the white and dark spots
He infers that Mars must have seasons
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The telescope era
In 1786, William Herschel also saw these changes He was able to determine Mars’ axial tilt at ~25 from the
ecliptic, which is the mechanism for seasonality He figured dark areas were seas and light areas clouds He thought the polar light spots were thin snow and ice He saw that faint stars that passed close to Mars were not
dimmed, inferring that Mars had a very thin atmosphere
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The Geographic Period: Telescopes plus maps
As telescopes improved by leaps and bounds, sketches of Mars did, too In 1800, Johann Hieronymus Schroeter makes drawings of Mars.
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The Geographic Period: Telescopes plus maps
William Beer and Johann H. von Mädler assembled the first real map of Mars in 1840
They use the first “areographic grid,” which is close to today’s They also refined Cassini's refinement of Huygens' estimate of the
Martian day: 24 hours 37 minutes 22.6 seconds
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The Geographic Period: Telescopes plus maps …
plus speculation In 1854, William Whewell speculates that there might be
Martian life He wonders if there are greenish seas and red landscapes
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The Geographic Period: Telescopes plus maps …
plus speculation In 1863, Jesuit monk Angelo Secchi draws a map and calls
the dark areas “canali” The dark triangle of Syrtis Major he dubs the “Atlantic Canal”
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The Geographic Period: Telescopes plus maps …
plus speculation In 1860, Emmanuel Liais suggests that the dark areas might
be vegetation, changing with the seasons In 1873, Camille Flammarion agrees that Liais might be on to
something, adding that maybe the red color itself is the color of the vegetation
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The Geographic Period: Telescopes plus maps … plus
speculation In 1867, Richard Anthony Proctor creates a map of Mars His pinpointing of the prime meridian is the one used today
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The Geographic Period: Telescopes plus maps …
plus speculation So, by the mid 1870s, there’s all sorts of exciting speculation
about Mars, stimulated by the ever-increasing resolution of telescopes: canali, dark seas, snowy polar caps, vegetation
It was known that the opposition of 1877 was going to be one of the best in decades, and everyone was looking forward to a great viewing opportunity coupled with the great new telescope capacity
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The Geographic Period: Telescopes plus maps …
plus speculation 1877 was a great opposition: Asaph Hall discovered the two
moons of Mars, Phobos and Deimos (Earth had one, Jupiter had four; therefore, Mars HAD to have two)
He had given up but his wife, Chloe Angeline Stickney Hall, kept after him and he found them.
In gratitude, he named the biggest crater on Phobos for her: Stickney
Interesting areotidbit: Jonathan Swift’s 1726 Gulliver’s Travels had the astronomers of Laputa talk about Mars’ two moons!
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The Geographic Period: Telescopes plus maps … plus speculation
The US Naval Observatory Telescope Hall used (still in service) Phobos’ and Deimos’ orbits
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The Geographic Period: Telescopes plus maps
1877 opposition was the basis of Giovanni Sciaparelli’s maps of the light and dark areas of Mars … and those linear features he called “canali”
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The Geographic Period: Telescopes plus maps
Schiaparelli’s map, different projection – brownie point …
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The Geographic Period: Telescopes plus maps
1892 saw some important questions raised: William Pickering of Harvard was seeing these
Schiaparelli channels, too, but he saw one running across "Mare Eruthraeum" : How could a “canal” run across a “sea”?
Edward Emerson Barnard spotted craters on Mars. No-one else paid much attention. He also said he tried and tried to see all these canals and couldn't for the life of him.
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The Geographic Period: Telescopes plus maps …
plus speculation 1893: Someone gives Percival Lowell a book about Mars by
Camille Flammarian: instant obsession Unlike most of us who get obsessions, he had $ He builds and staffs the Lowell Observatory in AZ In 1902, appointed at MIT as non-resident astronomer He publishes Mars in 1985, Mars and Its Canals in 1906,
and Mars, the Abode of Life in 1908
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration History of Earth-based Mars exploration
The Geographic Period: Telescopes plus maps … plus speculation Lowell publishes maps, with canals aplenty
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The Geographic Period: Telescopes plus maps …
plus speculation Lowell encounters resistance from the increasingly skeptical
scientific community Alfred Russell Wallace measured the light spectra from
Mars and concluded that the place was really, really cold, about -35° F, so Lowell's claim of water canals had to be "all wet”
Svante Arrhenius argued in 1912 that Mars might be covered with salts that change color with saturation and desiccation: No life necessary
Other scientists reported having trouble seeing canals
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The Geographic Period: Telescopes plus maps …
plus speculation Lowell responds by turning to popular audiences, shunning
the peer review that is central to science Public lectures, popular magazine stories His stories became more extreme Other scientists began to shy away from Mars A few, however, were caught up in Lowell’s beliefs:
Nikola Tesla claimed to detect radio signals from Mars in 1899
Guglielmo Marconi, of radio fame, also claimed to have heard from an alien radio transmitter
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The Geographic Period: Telescopes plus maps …
plus speculation The 60” Hale Telescope at Mt. Wilson turned up nary a canal In 1913, Edward Maunder did a psychological experiment
showing how the human eye tends to see patterns linking random lines and circles and the farther the observer was from the random pattern, the more likely they were to report linearities linking things in the pattern
Lowell dies in 1916, knowing that the scientific community thought Mars was not only uninhabited but uninhabitable
A few hardy souls held out for canals until Mariner
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration History of Earth-based Mars exploration
The Spectral Analysis era: A New Mars The electromagnetic spectrum can be displayed by wavelength
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The Spectral Analysis era: A New Mars
Spectral analysis in this context is the study of absorbed, emitted, and scattered radiation
A radiant object can emit wavelengths along the EMS at varying intensities: hot or dense objects emit across a continuous spectrum
Substances in the radiant object or between it and the sensor can absorb certain wavelengths
The wavelengths absorbed are diagnostic of particular minerals or elements or compound
Substances and surfaces also reflect particular wavelengths
C.M. Rodrigue, 2007Geography, CSULB
Mars: History of Mars Exploration
History of Earth-based Mars exploration The Spectral Analysis era:
A New Mars Some reflectance spectra:
water, carbon dioxide, methane