Mars and its Satellites
Mars, the red planet. Fourth closest to the sun
and named after the Roman God of War
Half the size of Earth and a lot colder. A desolate, barren
land with only a few really
distinguishable features, the Tharsis bulge
, the Elysium Plateau
, the two polar caps and the
. A wind swept, dusty desert
with little atmosphere
, and not much
. What are Mars’ secret
s? Is there life
? Could human
s ever live on Mars? Does
Mars have water
, and is the air
- Mars, the red planet is the fourth planet from the sun.
- In the time of ancient Romans, people named the planet Mars, after Mars, the god of
war, because its colour reminded them of blood.
- Mars has two natural satellites (moons). These are named Phobos and Deimos.
- Phobos and Deimos were named as they are because in mythology, Phobos (fear)
and Deimos (panic, terror) were the sons/secretaries of Mars/Ares (the Greek
version of the Roman Mars).
- Deimos is the smallest known moon in our solar system.
- The reason that Mars is red is because of the high iron content of the planet’s crust. Over the years, this has reacted with oxygen and water in the air to form
rust (a red substance that corrodes metals).
- Sometimes Mars has dust storms that cover the entire planet.
- Mars is colder than Earth as it is further away from the sun. A warm day on Mars is
equivalent to a cold day on Antarctica.
- Mars’ scientific planet symbol looks like a spear and shield, again form Mars/Ares.
- Mars’ day is almost exactly the same length of time as Earth’s day. Earth’s day has
a length of 23 hours 56 minutes long. Mars’ day is 24 hours 37 minutes and 23
- The tilt on the axis of these two planets, Mars and Earth is about the same - 24
- For a long time, people believed that intelligent life forms existed on Mars, these were
called Martians. One of the more famous Martians is Marvin, a Warner Bros
creation. According to Marvin, the Earth is a waste of space as it blocks the view of
- In 1938 in America, an actor named Orson Welles presented a radio play done in
broadcast style about aliens landing in a small New Jersey town. Hundreds of people
panicked, believing this to real, and left town, or locked themselves in their homes with
Mars in General:
Size of Mars:
Mars is approximately half the size of Earth, with a diameter
of 6,786 kilometer
s, compared to Earth’s 12,756 kilometers.
From Earth, Mars looks red, this due to oxidation
the surface. Mars’ rock landscape contains high percentages of the element Iron, and as
this corrodes, it turns red. Mars, like Earth, has two pole
s, one at the North
, and one at
. Like glacier
s, the poles extend and contract along Mars’ cold surface. While
the polar caps mainly consist frozen water, in the Martian winter, frozen carbon dioxide
more commonly known as ‘Dry Ice
’ is deposited on the surface of these caps. The cap at
the South pole is 300 kilometers wide, and at the North pole, the cap is over three times as
large, being 1000 kilometers wide. The true thickness of these caps is not truly known,
but it is possible that the ice and frozen gases on these caps have a thickness of 2
Mars’ surface has many rock
s and is covered in dust
. Carbon Dioxide
winds have been
known up whip up dust storms that cover the entire planet from time to time. The dust
from these storms (which occur between late spring and early summer in the Southern
hemisphere of Mars) is very fine, and takes a long time to settle. Mars is basically a
desolate and barren landscape, with no known plant
There are dry riverbed channel
s all over Mars, which shows that the red planet once had
flowing water, and possibly sea
s. This proves that Mars once had warmer temperature
and higher pressure
s. Now, however, the water has gone, but some scientist
some of it could be underground
The red planet’s surface has both valley
s and volcano
es. There have been two major
centres of past major volcanic activity found, known as the Elysium Plateau and the
Tharsis bulge. Olympus Mons
) is the biggest volcano on Mars, and is
one of four giant volcanoes located on the Tharsis bulge. It is nearly three times higher
than Mount Everest
, Earth’s highest mountain above sea-level. Olympus Mons has a
base diameter of 600 kilometers and has an elevation
of between 25 and 27 kilometers
above the average ground height
(there is no sea-level
). Though there has been no sign of
recent volcanic activity anywhere on Mars, scientists cannot be certain that all the
volcanoes are extinct
Mars doesn’t seem to have any tectonic plate
s, as there are no folded mountain belt
‘Marsquakes’. A seismometer
on board Viking 2
(Mars space probe
from America) failed
to detect any seismic activity
, but scientists cannot rule out the possibility of plates, as
some bulges and faults have been discovered by various probe
Interestingly, Mars has a extremely thick surface crust
, between 5 or 6 times as thick as
Earth’s. Mars’ crust has a thickness of 200 kilometers.
Another amazing feature of Mars’ surface is the Valles Marineris, a canyon
system that is
the longest and deepest (known) in the solar system. It is over 4,000 kilometers long and
up to 10 kilometers deep.
Two huge basin
structures down in the Southern hemisphere in the highlands are called
. Hellas has a diameter 1,500 kilometers and a depth of 7, and Argyre is
800 kilometers across and 2 kilometers deep.
Structure of Mars:
Mars has its rocky and dusty crust, which is 200
kilometers thick, then an extremely deep rocky stratum layer
, and finally a metallic core
Studies show that the metallic core is not likely to be liquid, as Mars doesn’t have a
The atmosphere of Mars is nearly completely carbon dioxide, at 95%. There is also 2.7%
, 1.6% argon
, 0.2% oxygen and minute amounts of water vapor
and other noble
es. If humans ever went to Mars, they could not
breathe without assistance from equipment
, as carbon dioxide in concentrated form is
ous to humans.
As Mars is, at all times, further away from the sun than Earth, it does not receive as much
heat. This makes a warm summer day on Mars colder than the coldest regions on Earth,
like Antarctica at our South pole. Amazingly, due to thin atmosphere, Mars’ temperatures
can change by 100 degrees Celsius
in one day. The warmest Mars ever gets is about -43
degrees Celsius, and the coldest is about -123 degrees Celsius
. Mars’ average
temperature has been recorded as -55 degrees Celsius.
Mars in the Solar System:
In terms of our planets, Mars is not big. Mars is the fourth planet from the sun, and
therefore colder than Earth. It is the last of the small planets before the giant planets start
. Mars is half the size of Earth, and twice as big as Earth’s natural satellite
, and the planet takes 687 Earth days (1.88 Earth year
s) to orbit the
sun once. The planet Mars spins on a 24-25 degree axis, basically like Earth, and
therefore has two cold poles, one in the North and one in the South. This angle of axis
produces seasons quite like Earth's, although every season is quite a bit colder. Mars’
orbit lies 1.5 times as far away from the sun as Earth’s. At Mars’ closest point in its orbit
around the sun, it is 206.7 million kilometers away from the sun. At its orbit’s furthest
distance, it is 249.2 million kilometers. The reason why Mars’ year is longer than Earth’s
is that it takes Mars almost twice as long to orbit the sun once than Earth.
Mars' History with Men:
Men and Mars. The relationship started thousands of years ago, with people first looking
into the sky. The ancient Romans named the planet after their God of War, as the rusty
colour reminded them of blood. Only when telescope
s really started examining the planet,
though, did people really start to know some of Mars’ secrets.
- In 1609, Johannes Kepler discovered that Mars’ orbital path around the sun is not
circular, but elliptical, like a squashed circle.
- In 1610, Galileo first used a telescope to view Mars. He recorded its phases.
- By the late 1600s, other scientists had already discovered that its day was about the
same length as ours, that its polar caps change with the seasons and that dark areas
could be distinguished. They thought these dark areas were seas, but we now know
that they are to do with weather cycles.
- In the late 1700s, an astronomer named William Herschel saw bright patches that
looked like clouds, and hypothesised that Mars had an atmosphere.
- In the late 1800s, an Italian astronomer named Giovanni Schiaparelli noted linear
markings that got termed canali. For more information, see about Life on Mars.
- Phobos and Deimos, the Martian Satellites were discovered by Asaph Hall in 1877.
Phobos is one of Mars’ two natural satellites (moons). Phobos is a small but heavily
ed lump of rock that is roughly ‘potato
’ shaped that orbits Mars. It is many
scientists belief that Phobos was once a asteroid
that flew too close to Mars and was
captured by gravity than a naturally occurred satellite.
Phobos has an average diameter of 20-28 kilometers. Its dimensions are roughly
27 x 21.5 x 19 kilometers.
A huge and well known crater on Phobos is named Stickney
after Angela Stickney
maiden name. She was married to Phobos’ discoverer, Asaph Hall. After searching for a
sign of any Mars satellites for many days, he told her that he was giving up. She
encouraged him to try for one more night, and sure enough, that night Phobos was
Phobos is about 4,800 kilometers from the planet, and 9,378 kilometers from the planet’s
core. It takes Phobos 7 hours and 39 minutes to orbit Mars once.
Some scientists believe that one day, Phobos will break up into lots of smaller chunks of
rock, and form a ring of rock around Mars, still on the same orbit ring.
From the surface of Mars, Phobos has a brightness of a very bright star on Earth’s light
multiplied several times.
Deimos is the smallest known satellite in our solar system. Like its partner Phobos,
Deimos is roughly potato shaped. Deimos has a diameter of 10-16 kilometers. It is about
11 x 12 x 15 kilometers.
Deimos’ orbital period
around Mars is longer than Phobos’ as it is further out. It takes
Deimos 30 hours and 18 minutes to orbit the planet once.
Deimos’ surface is heavily sprinkled with craters, a lot more so than Phobos. Scientists
also believe that Deimos, like Phobos, is a captured asteroid.
Deimos is found about 20,000 kilometers away from the planet Mars, and its brightness
from the surface of Mars would be the equivalent of the planet Venus at night to us.
A Recent History of Mars & Men:
What we really know about Mars is basically thanks to the United States of America
missions over the years. The first Mars space probe,
, was launched in 1964, and in July 1965, this probe passed within 9,600
kilometres of Mars’ surface. Mariner 4 took 19 close-up colour photograph
s of the
planet, and beamed these back to Earth, showing that Mars had craters like the moon, a
very thin atmosphere (only 1/100 of Earth’s) and no canals made by intelligent species.
Mars seemed to hold no life, intelligent
Mariner 4’s ‘sister’ (though up-dated) probes, Mariners 6
, were launched in 1969.
These also photographed Mars in flyby
s, and sent back photographs to NASA
In 1971, yet another Mariner reached Mars, this time Mariner 9
. The probe went into
orbit around Mars and mapped the entire planet by photograph. The pictures showed
Olympus Mons and the Valles Marineris.
In 1976, two new Mars probes caught the world’s attention. These were a new variety,
named Viking 1
and Viking 2
. The mission of these probes was not only to orbit mars and
take aerial photograph
s, but also to land on the Martian terrain
The Vikings managed to discover what Mars’ atmosphere consisted, take temperatures,
gather soil sample
s and analyse
them, and finally take many more photographs.
While the Vikings were launched at the same time, they didn’t land in the same place on
Mars, but had areas to search quite a long way apart. This was so that the scientists
working on the project had different data from different areas to work with.
The soil samples that the two Viking probes obtained showed a high iron content in the
soil of Mars and no apparent life. There was no carbon
in the soil (carbon is essential for
our kind of life) and no microscopic life form
s from either of the two landing sites.
Although there didn’t seem to be any life, these results could change, as only a tiny
percentage of Mars’ regions were tested by the probes.
Finally, in 1997, the Mars Pathfinder mission
arrived on Mars. Inside the Pathfinder, there
was a tiny robot named Sojourner
which was romote-controlled from NASA
headquarters. Sojourner tested more soil and took more photographs. It also studied
Mars’ rocks in detail. Many of the big rocks near Pathfinder’s landing site have been
tested and named, for example Shark
, Scooby Doo
. Yogi is
probably the most famous Mars rock, and the most extensively tested. Two other tested
areas are known as the Roadrunner Flats
and the Rock Garden
. There were still no signs
of life on Mars on the Pathfinder mission.
The Feasibility of Life on Mars:
Is anyone home?
For many years, people have associated the red planet with
life. Romans with people fighting battles, and the God Mars, science-fiction
Martians, Warner Bros
with Marvin the Martian, and Martians in general. Why?
Of all the planets in our solar system, mars is the one most like Earth, so therefore it was a
reasonable assumption to expect life. So is there life?
In the late 1800s, an astronomer named Giovanni Schiaparelli saw linear markings on the
surface of Mars. He named these in Italian, ‘canali’. By this term, he simply meant that
there were channel
s on Mars’ surface, but not canal
s. Some people began to believe that
these ‘canals’ were a sure sign of intelligent life on the red planet - who else could have
Now, of course, we know from the Mariner, Viking and Pathfinder missions that there are
no canals built on purpose by any form of life. Why did people see canals? This mistake
of astronomy is attributed to a visual illusion
in which the dark areas on Mars’ surface
seem to be connected lines.
Scientists are slowly piecing together the puzzle
of Mars’ history
. Once, people believe from the
dry riverbeds on Mars’ surface, Mars was warm, with running water. Maybe life could
have existed on the planet. Quickly, Mars turned into a hostile
terrain. Scientists don’t
believe that life could have evolved
fast enough to survive, but nobody is yet willing to
rule out the possibility of Martians...
Let’s go colonising!
r and more realistic
than it sounds. Quoting
the magazine Scientific American
, "America has the resources and technology to send men
". Fair enough, but do the benefits of terran colonisation
the dangers of sending people to the red planet?
NASA in America has hinted at a manned expedition to Mars in the year 2020, but there
are no final plans. People would have to take oxygen supplies, food and equipment, and
it’s a long journey to get there - 9 months! While it is true that men could search a
greater area of planet for life, and do detailed tests on rock and soil samples, nobody is
sure how well a possible mission would work. Also, a manned mission
would cost about
the same as 10 robotic mission
s, so the US Government
hasn’t indicated that American men will be
setting foot on the red planet any time soon.
It would be possible over a long period of time for men to slowly use a ‘green-house
effect on Mars, and warm the planet up. This would melt the polar ice caps to produce
water. If we added the right ‘ingredients’, or element
s, it would be possible for humans to
walk, breathe and grow with out assistance, but this is an extremely unlikely event.
Nevertheless, science-fiction fans can keep in their sights the possibility of Martian
colonisation, although it would be a cold and barren place to live...
U.S. President George W. Bush has announced that a manned mission to Mars may in fact take place at some point. Election gimmick, malarky, or effective way? Only time will tell...
Mars, the red planet, named after the Roman God Mars, is a cold
and hostile environment.
There are no obvious signs of life
, and no tests indicated any signs of past life having
existed. Many space probes have visited the red planet, and discovered that it is very like
Earth in its axis tilt, poles, seasons and day. Mars has two natural satellites, Phobos and
Deimos, both of which support many craters. Mars has some amazing geographical
features, from the towering Olympus Mons to the winding Valles Marineris. Half the size
of Earth, and nine months away, Mars is a barren and harshly terrained neighbour
: Its connection to the god of war dates back much further. Gugalanna
and Ares were all associated with it.
: Mars was named in the time of the greeks, I believe, named Ares, after the greek god of war. The romans later gave new names to the greek gods when they adopted them as their own, and therefore new names to the planets.
- Scientific American - March 2002, May 1998 + SE Quarterly
- New Scientist - September 1997
- National Geographic - August 1998
- The Inner Planets - Neil Ardley, Schoolhouse Press, 1987
- Discovering the Planets - Jacqueline Mitton, Eagle Books, 1991
- Mars - Dinah Moche, Franklin Watts, 1978
- Mars: Our Mysterious Neighbour - Isaac Asimov, Gareth Stevens Publishing, 1988
- Mars - Elaine Landau, Franklin Watts, 1991
- Planets and Satellites - Various authors, Belitha Press, 1994
- Mars - Seymour Simon, A & C Black, 1987
- Phillip’s Atlas of the Universe - Patrick Moore, George Phillip Ltd., 1997