c.m. rodrigue, 2015 geography, csulb mars: history of exploration ii geography 441/541 s/15 dr....

C.M. Rodrigue, 2015Geography, CSULB

Mars: History of Exploration II

Geography 441/541S/15

Dr. Christine M. Rodrigue


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/reflected 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


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



History of Earth-based Mars exploration The Spectral Analysis era:

A New Mars Some reflectance spectra: water carbon dioxide methane


Mars: History of Mars Exploration History of Earth-based Mars exploration

The Spectral Analysis era: A New Mars Continuous spectra Emission line spectra Absorption line spectra



History of Earth-based Mars exploration The Spectral Analysis era: Martian air pressures

In 1862, Sir William Higgins tried out the new technology to get at Martian atmospheric pressures: All he got was that sunlight reflected off Mars and the planet didn’t glow

In 1867, he and Pierre Jules Jenssen took spectra of Mars to look for water vapor and oxygen and found none

In 1908, Percival Lowell also tried spectroscopy: Mars’ air pressure looked like 87% of Earth’s His method was sound, but he didn’t correct for dust Erroneous as his results were, the method was a

significant contribution to launching the use of spectral analysis on Mars and other planets



History of Earth-based Mars exploration The Spectral Analysis era: Martian temperatures

Any object that absorbs radiation re-emits it at a longer wavelength, because it is necessarily cooler than the original radiant body

Wien’s Displacement Law (L = 2,897 / TK ) allows you to calculate temperatures (TK = 2,897 / L )

In the 1920s, Lowell Observatory established that Mars was very cold, -40 C on average (Earth averages 15 C)

The poles got down around -70 C, and the equatorial areas got as warm as 10 C

In 1954, equatorial highs got as high as 25 C



History of Earth-based Mars exploration The Spectral Analysis era: Life on Mars?

Mars shows seasonally shifting patterns of spring darkening Some folks inferred that this could be a wave of vegetation

greening up for spring In 1938, Peter Millman compared the spectra from the dark

areas with spectra that had been collected for various kinds of vegetation here on Earth and said they did not resemble one another at all

In 1954, W.M. Sinton said these spectra did resemble organic compounds, later retracting this

Audoin Dofus and Thomas McCord showed that the dark areas were not greenish: That was an optical illusion


Mars: History of Mars ExplorationHistory of Earth-based Mars exploration

Telescope observation from near-Earth Hubble Telescope was designed in 1973, since the Shuttle

had been recently approved as a way of schlepping it out Congress funded it in 1977 and it launched in 1990 It’s a reflecting mirror type of telescope The main (2.4 m) mirror turned out to have an optical flaw,

enough to give it astigmatism Corrective optics applied in 1993 Hubble is no longer being serviced and its equipment is

breaking down: Its orbit will eventually decay (~2019-2032) Angular resolution is 0.05 arcsecond

"If you could see as well as Hubble, you could stand in New York City and distinguish two fireflies, 1 m (3.3 feet) apart, in San Francisco."



History of Earth-based Mars exploration Telescope observation from

near-Earth: Hubble Both infrared and visible

light imaging of Mars Best resolution: 19 km Got best images in August

2003, the best opposition in 59,619 years



History of Earth-based Mars exploration Telescope observation from near-Earth -- Hubble has:

Monitored weather (very useful when Mars Global Surveyor was ærobraking into Martian orbit in 1997!)

Caught a 1996 spring dust storm

Documented cloudiness in 1997

Caught a polar cyclone in 1999

Identified water-bearing minerals on Mars


Mars: History of Mars Exploration History of the Robotic Missions to Mars

Hugely dangerous: More than half of the missions have failed (about 51%) "Great Galactic Ghoul," Mars as the "Bermuda Triangle," the "Mars Curse" There have been launch failures

USSR Mars 1960A failed at liftoff

Russian Space Agency Mars 96 orbiter/lander/penetrator

NASA Mariner 8 1971

RFSA Phobos-Grunt 2011 Communications failures

USSR Mars 1 (aka Sputnik 23) 1963

NASA Mars Observer lost contact at arrival in 1993 Orbit insertion failures

Japan ISAS Nozomi 1999 *and* 2003 Crashes on the Martian surface

NASA Mars Climate Observer 1999

NASA Mars Polar Lander/Deep Space 2 1999

ESA Beagle lander 2003



History of the Robotic Missions to Mars Dangerous!

1960s 1970s 1980s 1990s0

1

2

3

4

5

6

7

8

9

Fate of Missions to Mars

Success

Partial success

Failure

Decade

Nu

mb

er



History of the Robotic Missions to Mars Spacecraft types

Flyby missions (Cassini-Huygens gravity-assists by Earth and Venus; New Horizons encounter with Pluto in July 2015)

Orbiters (Earth’s Landsat, IKONOS, SPOT)

Probes (Huygens probe at Titan, NEAR at asteroid EROS)

Landers (USSR Venera, NASA Surveyor on Moon)

Rovers (Spirit and Opportunity, Earth portable spectrometers)

Penetrators (USSR Mars 96 had two)

Balloon probes (USSR Vega 1 at Venus)

Sample return missions (MSRL, Genesis from L1, Stardust from Comet Wild 2)


Mars: Remote Sensing Basics Resolution

Spatial Varying, as in a descending probe (e.g, Huygens descending to Titan)

Fine resolution, 0.5 – 5.0 m (e.g., IKONOS, OrbView-3)

Coarse resolution, 1 km (e.g., MODIS) to 8 m (e.g., GEOS)

Vertical Generally worse than horizontal spatial resolution Generated by laser altimeters, InSAR, stereo pairing


Mars: Remote Sensing Basics Resolution

Radiometric How finely differences in values can be detected Function of bits in a byte

Directional Nadir only Backward/forward or right/left Reflectance and scattering by wavelength differ by direction

Spectral Panchromatic (all bands within a large range, often fine resolution) Multispectral (3-100 or so bands, at discrete intervals along the spectrum)

Hyperspectral (16-220 narrow bands contiguous to one another over a spectral range)

c.m. rodrigue, 2015 geography, csulb mars: history of exploration ii geography 441/541 s/15 dr....

Documents

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