Mars 2 ... continuing the discovery of information on the Red
The sunset image is from the Pathfinder
Mission, and demonstrates that romantic evenings can be possible on Mars,
but kissing through helmets might dampen the mood.
has permanent ice caps at both poles composed mostly of solid carbon dioxide
("dry ice"). The ice caps exhibit a layered structure with alternating
layers of ice with varying concentrations of dark dust. In the northern summer
the carbon dioxide completely sublimes, leaving a residual layer of water ice.
It's not known if a similar layer of water ice exists below the southern cap
(left) since its carbon dioxide layer never completely disappears. The mechanism
responsible for the layering is unknown but may be due to climatic changes related
to long-term changes in the inclination of Mars' equator to the plane of its
orbit. There may also be water ice hidden below the surface at lower latitudes.
The seasonal changes in the extent of the polar caps changes the global atmospheric
pressure by about 25% (as measured at the Viking lander sites). The image to
your left is of the North Polar Cap in mid-Martian summer. The diameter of this
cap is about 1100 km, and most of what you see is frozen water.
Recent observations with the Hubble Space Telescope have revealed that the
conditions during the Viking missions may not have been typical. Mars' atmosphere
now seems to be both colder and dryer than measured by the Viking landers. (
more details from STScI)
landers performed experiments to determine the existence of life on Mars.
The results were somewhat ambiguous but most scientists now believe that they
show no evidence for life on Mars (there is still some controversy, however).
Optimists point out that only two tiny samples were measured and not from the
most favorable locations. More experiments will be done by future missions to
the Mars Sojourner and Pathfinder
missions successfully landed on the surface. A small robotic car moved around,
taking pictures and making close analysis of rock types. A few images from that
mission are included below, and if you want to see more surface photos, click
on the Pathfinder website.
A small number of meteorites (the SNC meteorites) are believed to have originated
1996 Aug 6, David McKay et al announced the first identification of organic
compounds in a Martian meteorite. The authors further suggest that these compounds,
in conjunction with a number of other mineralogical features observed in the
rock, may be evidence of ancient Martian microorganisms. I was out in the San
Francisco area when this Mars meteor story broke from the Ames Research Center.
It was incredibly exciting to be so close to the action. Exciting as this is,
it is important to note while this evidence is strong it by no means establishes
the fact of extraterrestrial life. There have also been several contradictory
studies published since the McKay paper. Remember, "extraordinary claims
require extraordinary evidence." Much work remains to be done before we
can be confident of this most extraordinary claim. Whether anyone ever really
proves the geological formations in the rock to be bacterial fossils or not
is not as important as the effect this story had on the public in general and
the politicians in particular. When NASA asked for money to fund extra Mars
missions, the Federal Government was more than willing to cough up some large
dollar figures because of the potential of finding evidence of life, if not
even life itself underneath the surface dust. Keep in mind that the lack of
an appreciable atmosphere means no gases to block harmful solar radiation. Any
life forms living on the surface would suffer extreme radiation and mutate to
death. Indeed, the movie "Total Recall" shows mutant humans who suffered
their horrible fate when the original Mars settlers constructed domes of cheap,
non-UV protective glass.
but not global, weak magnetic fields exist in various regions of Mars. This
unexpected finding was made by Mars
Global Surveyor (seen in an artist's rendition to your left, photographing
Olympus Mons) just days after it entered Mars orbit. They are probably remnants
of an earlier global field that has since disappeared. This may have important
implications for the structure of Mars' interior and for the past history of
its atmosphere and hence for the possibility of ancient life.
Also orbiting Mars presently is the Mars
Odyssey satellite. This satellite is bouncing laser beams off the surface
to generate fantastic topographic maps
These current satellite missions are accomplishing wonders, and a trove of
new scientific data is accumulating which will give engineers, geologists, and
terraformers plenty of work to keep them busy for many years to come. To see
the current progress, check out the JPL
When it is in the nighttime sky, Mars is easily visible with the unaided
eye. Its apparent brightness varies greatly according to its relative position
to the Earth. There are several Web sites that show the current position of
Mars (and the other planets) in the sky. More detailed and customized charts
can be created with a planetarium program such as Starry Night.
Mars has two tiny satellites which orbit very close to the surface:
Meaning of name
To learn more about these two little moons, go to Martian
Moons. ("Distance" is measured from the center of Mars).
During the 1999
Nobel Conference at Gustavus College, I had the opportunity to listen to and
then meet Dr. Roald Sagdeev. He was a former head of the Soviet Space Research
Department and a project director for several Soviet satellite missions. After
listening to his speech, purchasing and reading his book, I found a few interesting
things about their program, as well as the US program. The Soviets and Americans
had reached a gentleman's agreement. America would send spacecraft to Mars and
share information, while the Soviets would send spacecraft to Venus and share
information. Over the ensuing 10-15 years, the two bitter Cold War enemies shared
science information despite their military disagreements. Apparently, the Soviets
and Americans were working on star wars technology, which meant laser weapons
capable of destroying space satellites, either from space or from the ground.
Since the Star Wars Treaty was signed by America and the Soviet Union, it was
impossible to test the technology without the other side knowing it. But the
Russians had a pretty interesting plan. They were going to send a space probe
to Mars' moon Phobos and then blast material off the surface, catch it in a
web, and return samples to Earth for analysis. An excellent instrument to do
this blasting would be a powerful laser. Fortunately, for the Americans, they
had spies in the Soviet program so they knew this laser test was not a space
mission but a military test. The Americans therefore made a proposal to the
Soviets. If the Soviets were willing, would they mind if a wonderful new camera
America was testing could be attached to the Soviet craft. Caught "red-handed"
the Soviets had to agree. Now the Americans could aim their camera, not at the
surface of Phobos, but at the Soviet star wars laser weapon. Unfortunately,
both Phobos 1 (seen in an artist's rendition to your left) and its back-up Phobos
2 were lost, and both "tests" failed.
is the JPL website that will offer more information than I can place in this
course, as well as some nice connecting links.
Fossils? This is the rock that caused all of the excitement in 1996. Known
more simply as ALH84001.0, this rock held tiny geological formations that looked
remarkably like bacterial fossils.
For more on the story, click on the website.
The images above can be found at the Mars
Society, a group of private citizens dedicated to the exploration, terraforming,
and colonization of the Red Planet.
Well, there it is, Cydonia ... the supposed site of an alien city on Mars.
Martian Pyramids is
a website that is devoted to the meaning of these strange features on the surface,
imaged by the Viking missions in the 1970's. For years, the "face on Mars"
has fascinated the public, as too has the pyramids. In fact, these very pyramid
structures, seen in the lower left of the left image above, inspired the movie
No single person has more connection to Mars than Percival Lowell. His story
is one of the most interesting accounts in the history of Astronomy. Excited
by the visions of canals reported by Giovanni Schiparelli, Lowell founded an
observatory at Flagstaff, Arizona and dedicated himself to the study of Mars.
The more Lowell studied Mars, the more he saw there. Soon he was seeing a vast
system of canals, literal straight-line channels running all over the surface,
connecting the polar caps to cities and junctions. Their purpose, according
to Lowell was to help a race of Martians survive a dying world. Lowell's book
can be read by clicking on the web site.
The visions and writing of Lowell inspired an entire industry. HG Wells was
inspired to write a book, The War of the Worlds which depicted the Martians
coming to the Earth where there was a plentious supply of water. Orson Wells
narrated the story in 1938 on a public radio broadcast. Americans from coast
to coast were frightened by the reading, many hid in the homes, and others committed
suicide. To read his entire book, click on the War
of the Worlds by HG Wells for the complete text.
After HG Wells, Edgar Rice Burroughs wrote a series of Mars-related books.
The collection of books by Edgar Rice Burroughs is on line, with complete texts.
Princess of Mars,
Gods of Mars,
Warlord of Mars,
and Thuvia, Maid
Two movies, of the many that have tickled our fancy with Mars stories can
be looked upon briefly at Mission
to Mars and Mars Attacks.
fascinating site, if you have ever watched the movie "Aliens" (the
second in the "series"), deals with the subject of terraforming a
planet. The idea in the movie was to construct a huge machine that would manufacture
air and make an entire planet liveable. The movie called it a "shake and
bake colony." While Mars cannot hold an atmosphere due to its lack of sufficient
mass, some have proposed digging a deep hole, closer to the interior to that
gravity will then be able to hold on to the oxygen that might be put there.
Other ideas include burrowing into the sides of the Valles Marineris, like in
the movie "Total Recall."
To see some interesting proposals on the subject, click on Terraforming
Perhaps the most interesting site I have found to date that deals with lore
and truth about Mars is the Chronology
of Mars website. This places has connections to information about Mars going
back to the beginning of history, a connection to every mission to Mars whether
it was successful or a failure, and a connection to fun stuff about the planet.
You can see a condensed version of the Chronology
of Mars that I copied into the course strictly for educational purposes
Now, it is time to do something really cool. The Mars
Global Surveyor is returning images of the Red Planet's surface, and planetary
geologists are trying to cataloge the craters. Since the task is beyond the
ability of grad students and their professors, a website has been opened that
allows any student of Astronomy an opportunity to do meaningful work related
to these Martian craters. Please go now to the
Mars Crater Page and
check out your lab assignment connected with this course.
To learn more about planet Mars, go to the JPL
webpage and click on Mars.
Here are 10 questions I would like you to answer about
the planet Mars.
1) Give a brief description of the planet's surface
2) What gives Mars its red color?
3) What is so special about Olympic Mons?
4) Why might the Mars Society be interested in the Valles
5) What are the names of the 2 moons of Mars?
6) Why would water boil on Mars?
7) Why would glass domes be necessary in a surface city
to protect the pioneers that would want to live on Mars?
8) What spacecraft first landed on Mars and when did
this event take place?
9) What is the current scientific interest in the Martian
soils and rocks that might tell us about the geologic history of Mars?
10) What are the polar caps composed of and what happens
to them in summer?
There is so much to Mars, in fact more than an entire course could possibly
hold, and as time goes by, perhaps more of the interesting Mars stories, fictional
and true, can be included in this course. Before you go any further, how
about checking to see if you are certain about your answers to the short quiz
above, and then sending your response my way at the Mars
For now though, it is time to move on. Please go to
to the Gas Giants page.
| Home | Course
Assignments | Teacher Bio
| Course Units
| Syllabus | Links