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MARS - THE RED PLANET
Dr. Yasser M. Abdou
PhD in Experimental Neutrino
Astrophysics
Mars
Roman God of War
the equivalent of the
Greek god Ares
 Phobos (Fear) and
 Deimos (Panic)
History
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Mars in our Daily Life
Tuesdays are Mars Days!
The Month of March Belongs to the Red Planet Too!
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Film & Radio
Radio : Tuning in Mars
Below are some of the films to look for in your video store:
Movie Title
Year
John Carter
2012
Mars Needs Moms
2011
Princess of Mars
2009
War of the Worlds 2
2008
Martian Child
2007
Doom
2005
War of the Worlds
2005
…................
….....
Flash Gordon: Mars Attacks the World
1938
Aelita: Queen of Mars
1924
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MARS
 FOURTH PLANET FROM THE SUN
 NAMED AFTER THE ROMAN GOD OF WAR
 DESCRIBED AS THE “RED PLANET”
 THE IRON OXIDE PREVALENT ON ITS SURFACE GIVES IT A
REDDISH APPEARANCE
 A TERRESTRIAL PLANET WITH A THIN ATMOSPHERE
MARS LOCATION
MARS
MARS FACTS
 DISTANCE FROM SUN ≈1.52 TIMES AS FAR AS EARTH
 TIME TO ORBIT THE SUN ~ 26 EARTH MONTHS
 ATMOSPHERE ~ MOSTLY CARBON DIOXIDE
 MARTIAN DAY ~ 24.7 HOURS
 TEMPERATURE ON THE PLANET’S SURFACE HARDLY RISES ABOVE
FREEZING POINT
EARTH AND MARS | COMPARISON
PARTICULARS
EARTH
MARS
RADIUS
6378 KM
3397 KM
DENSITY
5515 KG/M3
3933 KG/M3
GRAVITY
9.8 M/S2
3.72 M/S2
YEAR
365.25 DAYS
686.98 DAYS
ECCENTRICITY
0.017
0.094
DAY
24 HOURS
24 HR 39 MIN
OBLIQUITY
23.45º
25.19º
MARS | SURFACE FEATURES
 SURFACE COLOR “RED”
 FEATURES
 IMPACT CRATERS
 LARGEST VOLCANO IN THE
SOLAR SYSTEM
 (OLYMPUS MONS)
 LARGEST CANYON IN THE
SOLAR SYSTEM
 (VALLES MARINERIS)
 ANCIENT RIVER CHANNELS
 LAVA ROCKS
 DUST: REDDISH FROM
VOLCANIC ROCK
VALLES MARINERIS
MARS | ATMOSPHERE
 UNBREATHABLE
 THIN
 DUSTY, MAKES THE SKY PINKISH, LOTS
OF DUST STORMS
 SURFACE PRESSURE: 1/150TH OF EARTH’S
(ONLY 5.6 MILLIBARS)
 COMPOSITION: 95% CO2, 3% N, 1.5% AR,
0.1% O2, 0.03% H2O
MOONS OF MARS
PHOBOS
 MARS HAS TWO TINY MOONS NAMED “DEIMOS” (PANIC) & “PHOBOS” (FEAR)
Deimos
 THE MOONS ARE IRREGULAR AND VERY
SMALL IN SIZE
 PHOBOS 27X22X18 KM
 DEIMOS 15X12X10 KM
 THE MOONS ARE PROBABLY ASTEROIDS CAPTURED BY MARS
WATER ON MARS
 WATER IS THE KEY TO LIFE AS WE KNOW IT
 THE NORTH AND SOUTH POLES OF MARS ARE COVERED WITH THICK ICE
OR FROST
 SOME ASTRONOMERS ABOUT 100 YEARS AGO THOUGHT THERE WERE
CANALS ON MARS DUG BY INTELLIGENT CIVILIZATION
 SPACE PROBES TO DATE HAVE NOT FOUND ANY TRACES OF CANALS ON
MARS
IMPACT CRATERS ON MARS
 IMPACT CRATER IN MARS IS A LARGE HOLE IN THE GROUND CAUSED BY A
METEORITE SMASHING INTO THE SURFACE OF MARS
 EVERY SOLID BODY IN THE SOLAR SYSTEM SUFFERS FROM THE EFFECTS OF
IMPACT CRATERING
 THE PROJECTILES THAT CAUSE IMPACT CRATERS, TRAVEL AT VERY HIGH SPEED
AND FASTER
REASON FOR OCCURRENCE OF IMPACT
CRATERS ON MARS
 FORMED BY A LARGE OBJECT SUCH AS AN ASTEROID OR A COMET
 WHEN THESE LARGE OBJECTS HIT THE SURFACE THEY FORM HOLES (CRATERS)
 LATE HEAVY BOMBARDMENT PERIOD OF OUR SOLAR SYSTEM
 NO ATMOSPHERE TO PROTECT IT FROM ASTEROIDS
 THAT'S WHY MARS HAS CRATERS
PHOTOGRAPHS OF VARIOUS IMPACT CRATERS
ON MARS
CONTD…
Why was Mars warmer and wetter in the past?
Mars’s atmosphere must once have been much thicker
with a much stronger greenhouse effect, though we do
not yet know whether this made Mars warm and wet for
an extended period of time or only intermittently.
Why did Mars change?

Change must have occurred due to loss of atmospheric
gas, which weakened the greenhouse effect.

Some gas was probably blasted away by impacts, but

more probably was stripped away by the solar wind as
Mars cooled and lost its magnetic field and protective

magnetosphere.

Water was probably also lost because ultraviolet light
could break apart water molecules in the atmosphere,
and the lightweight hydrogen then escaped to space.
Seeking Life on Mars
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Astrobiological Space Missions
Flyby(goes past a world just once and then continues on its way.)
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The craft flies by the destination;
Relatively easily accomplished;
Voyager, Pioneer 10 & 11
Orbiter
The craft enters into an orbit around the object;
allowing longer-term observation during its repeated orbits
More difficult to achieve;
Galileo (to Jupiter).
Lander
A (usually) soft landing is intended;
Considerable deceleration must be achieved;
Phoenix, Mars rovers.
Sample & return
Samples are obtained and returned to Earth;
Extremely difficult;
Often financially draining, but politically popular;
e.g. Apollo, Luna
Past
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Present
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Future
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Other places on Earth that can help us understand Mars
include:
Death Valley, California, where Ubehebe crater and "Mars Hill" have geologic
features similar to those on Mars
Mono Lake, California, which is a 700,000-year-old evaporative lake that
compares to Gusev Crater, a basin on Mars where water once was likely
Channeled Scabland in Washington, where catastrophic floods swept
through the land much like what happened long ago in the Ares Vallis flood plain
where Mars Pathfinder landed
Permafrost in Siberia, Alaska and Antarctica, where subsurface water-ice
and small life forms exist
Volcanoes in Hawaii, which are like those on Mars, though much smaller
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Three key requirements for life
1.
Source of molecules (easily accomplished)
– The biologically important atoms C, H, O, N are universal;
– Amino acids are also available in the environment;
– Amino acids are easily manufactured (Miller Experiment).
2.
Source of energy (a little more difficult)
– Solar radiation (drops with inverse square law);
– Chemical reaction rates drop by a factor of 2 for each 10ºC drop;
– Hydrothermal vents;
– Other exotic energy sources.
3.
Liquid water (a key limitation)
– Water transports nutrients in, and toxic wastes out;
– Water expands when it freezes;
– Water is liquid over a very wide range of temperatures.
Is Mars habitable?
Mars almost certainly had a habitable surface during
its wet periods more than 2–3 billion years ago.
Its surface or near-surface might still sometimes be
habitable when its axis tilt is greater than it is now,
and the subsurface may still have habitable
regions today.
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Three lines of evidence
1. Gas
emissions;
2. Martian meteorites;
3. Viking.
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Evidence: Methane on Mars
Five sources for this gas:


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Cometary impact—extremely unlikely for methane.
Human contamination—ruled out by spatial resolution, and the
timing of the discovery.
Volcanism—not seen, but such energy sources would be
fabulous for life.

Weird geological or chemical reactions???

Life itself!
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Evidence: Martian Meteorites
In 1984, an expedition to the Allan Hills region of Antarctica picked
up a 1.9 kg rock, thereafter called ALH84001.
Isotopic ratios of 16O, 17O, 18O show this is not an Earth rock.
These isotopic ratios strongly imply it is not an asteroidal chunk, or
a piece of the Moon, either.
Gas samples trapped in the rock are consistent with it being a
chunk of Mars.
Only 34 Martian meteorites have been found.
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ALH84001 history
4.5 b.y.a.
The parent rock solidified from molten material. (The southern highlands are
suspected as the meteorite’s origin—spectroscopy matches with Eos Chasma in
Valles Marineris.)
4-4.5 b.y.a.
Heavy bombardment shocks occurred near the parent rock. (The meteorite
contains characteristic shock structure).
3.9 b.y.a.
Liquid water seeped into the rock, leaving behind carbonate grains 0.1-0.2mm in
diameter. (From radiometry of minerals in the fractures.)
16 m.y.a.
The rock was blasted into space to drift. (Based upon cosmic ray exposure.)
13,000 y.a.
The meteorite impacted Antarctica. (Based on the age of ice layers at Allan Hills.)
1984
ALH84001 was found by humans during a meteor-hunting expedition.
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Is there evidence of life in martian meteorites?
Evidence have been presented as suggesting the presence of
past life in a martian meteorite, but each also has a potential
nonbiological explanation.
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Viking
Viking results
In 1976, two probes to Mars carried basic biological labs to look for
life on Mars.
The Viking probes were equipped with robotic arms that could scoop
out Martian soil and bring it on board for analysis.
The number one priority: search for evidence of life!
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Viking
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Viking Biology Experiments
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Labeled release experiment, looked for signs of metabolism
Pyrolytic release experiment, looked for signs of photosynthesis

Gas exchange experiment, looked for signs of respiration
Is there any evidence of life on Mars?
The Viking experiments produced results that some scientists
think may be evidence of life, but nonbiological explanations
seem more likely.
Recent observations have detected methane in the
atmosphere, which may be due to life or may simply be
due to volcanism.
Overall, there are some possible hints of life on Mars, but no
definitive evidence.
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Human Settlement on Mars
Aime: Send humans to Mars and to sustain life there.
Mars Websites
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http://mars.jpl.nasa.gov/classroom
http://mars.jpl.nasa.gov
http://marsed.asu.edu
http://msip.asu.edu
http://marsbound.asu.edu
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