Mars, which has a striking red appearance, is the fourth planet from the sun and the seventh largest in the solar system, only Mercury is smaller. Scientists believe Mars is red due to various oxides - particularly iron oxides - on its surface. Mars is named after the Roman god of War (Ares to the Greeks). The name of the month March is derived from Mars.

It is a relatively small world that seems to be cold and dry. Its surface exhibits many Earth-like features, although its craters and monochromatic color scheme are suggestive of Earth's Moon as well. It has an extreme day to night temperature difference due to its thin atmosphere. Temperatures range from about 80F (27C) at noon, to about -100F (-73C) at midnight. Its atmosphere consists mainly of Nitrogen and Argon. Mars is roughly twice as bright as Sirius, the brightest star apart from the sun. The brightness of Mars varies with its position in its orbit. It has a diameter a little more than half of Earth's - 4200miles (6800km) - and about 11% of the mass of the Earth.


Mars' orbit is significantly elliptical. Mars' average distance from the Sun is 230 million kilometers, or about 1.5 astronomical units (A.U.). Its orbital period is 687 Earth days. A solar day on Mars is slightly longer than an Earth day. Its perihelion is 207 million km and its aphelion is 249 million km.


Like earth and most other planets mars rotate with a siderial period of 24 hours and 37 minutes. Mars rotation is characterized by the position of its poles in the celestrial sphere.


Mission Country Launch Date Type Notes
Mars-1960A USSR 10-10-1960 Flyby Failed to reach Earth orbit
Mars-1960B USSR 10-14-1960 Flyby Failed to reach Earth orbit
Mars-1962A USSR 10-24-1962 Flyby Aborted as it entered orbit. Pieces remained in orbit for a few days.
Mars1 USSR 11-01-1962 Flyby Communication failed when it was 760,000km from Earth (03-21-1963)
Mars1-1962B USSR 11-14-1962 Lander Failed during Trans-Martian Insertion (TMI) attempt
Mariner 3 USA 11-05-1964 Flyby Failure to eject the equipment shield prevented it from attaining a Mars Trajectory
Mariner 4 USA 11-28-1964 Flyby Arrived 07-14-1965. Returned 22 images of Martian surface. Closest approach: 9912km
Zond 2 USSR 11-30-1964 Flyby Carried same instruments as Mars1. Communications failed enroute
Mariner 6 USA 02-24-1969 Flyby Arrived 07-31-1969. Collected surface and atmospheric data. Returned 75 images. Closest approach: 3330km
Mariner 7 USA 03-27-1969 Flyby Arrived 08-05-1969. Identical to Mariner 6. Collected data relevant to the search for life on Mars. Returned 126 images. Closest approach: 3518km
Mars-1969A USSR 03-27-1969 Orbiter Exploded seconds after launch.
Mars-1969B USSR 04-02-1969 Orbiter Detonated early in launch.
Mariner 8 USA 05-08-1971 Flyby ...

Phobos? Pathfinder? Spirit? Phoenix?


Saturn moon Project Mars has two small moons, Phobos and Deimos. They are thought to be captured asteroids or satellites. There is no right theory as to how Phobos and Deimos came to be in orbit around mars. The most likely scenario suggest that these moons are probably asteroids perturbed by the giant gravity of Jupiter into orbits that allowed Mars to captur them. If correct Phobos and Deimos should be composed of carbon and rich rock like c-type asteroids. Since their densities are so low they can't be pure rock. They are more likely to be composed of an mixture of rock and ice. Both moons are heavily cratered. The motion of Phobos and Deimos appear very differnt from our own moon. Both moons are tidally locked always presenting the same face towards Mars. Since the sun angular diameter is 21' there are no total solar eclipses on Mars because the moons are to small to cover the entire sun. Another scenario suggest that they are fragments of larger objects broken apart in a collision. Such moons may be formed from collisions of objects originally in orbit around the planet or they might also have captured gravitationally at some point in the past. Since the moons have surface materials similar to many asteroids in the outer asteroid belt it leads most scientist to believe that Phobos and Deimos are captured asteroids.


                                 PHOBOS            DEIMOS


ORBITAL PERIOD (MARS DAYS) 0.31891 1.26244



MASS(x10to15 KG) 10.8 1.8

MEAN DENSITY 1900 1750


Phobos is the larger and innermost of Mars's two moons. Phobos is closer to its primary than any other moon in the solar system. It is also one of the smallest moons in the solar system.Phobos is Greek for fear. They were discoverd on August 12,1877 by Asaph Hall. It was photographed by MARINER 9 in 1971, VIKING 1 1977, PHOBOS in 1988. Phobos orbit Mars below the synchronous orbit radius. It rises in the west, moves rapidly across the sky and sets in the east, at least two times daily. It takes about 11 hours for it to rise again. Phobos orbit Mars faster than the planet itself rotates, tidal forces are slowly but steadily decreasing its orbital radius. At some point in the future when it approaches Mars closely enough phobos will be broken up by these tidal forces.


Deimos is the smaller and outermost of Mars two moons. It is also the smallest known moon in the solar system. In Greek mythology Deimos is known as the son of Ares (Mars) and Aphrodite (Venus). Deimos is Greek for panic. Deimos was first discovered August 10,1877 by Asaph Hall and photographed by viking 1 1977. When looking at Deimos from the surface of Mars near its equator it looks more like a bright star or planet. It's only slightly bigger than Venus looks from earth. The diameter is angular and about 2'. Since Deimos is outside synchronous orbit, it's expected to rise in the east very slowly. Despite the 30 hour orbit it'll take 2,7 days to set in the west as it slowly falls behind the rotation of Mars and begins to rise again. Deimos is far enoughr away that its orbit is slowly boosted just like our own moon but unlike Phobos. Deimos orbit 23,459 km from Mars. Its shape is 15 x 12.2 x 11 km, Mass 1.8 x 1o to 15 kg.

Ice caps

Mars has ice caps at both north and south poles the permanent portion of the north polar cap consists almost entirely of water ice. In the northern hemisphere winter, this gains a seasonal coating of frozen carbon dioxide and dry ice about 3 ft. thick. The South polar cap aquires a thin frozen carbon dioxide coating in the southern hemisphere winter. Beneath this is the permanent polar cap which is in two layers. The top layer consist of frozen carbon dioxide and about 27 ft. thick, the bottom layer is very much deeper and is made of water ice. Data collected by Mars radar instrument has indicated that enough water is locked up at Mars's south pole to cover the planet in all liquid layer 36 ft. deep. The northern cap is larger and colder. During the southern hemispheres summer the ice cap sublimates, a process in which the ice turns straight back into gas leaving behind what is known as the residual polar cap. This problem occurred because the winter cap is symmetrical about the south pole. The residual cap is offset by some three to four degrees. The seasonal warming and cooling of the poles effects weather and climate on Mars. Researchers at the Carl Sagan Center suggest that how much light Mars reflects is a major factor in the warming. As tha caps shrink they develop dark spots, rifts, and a ragged border. During the Martian summer the polar cap in that hemisphere shrinks and the dark regions grow darker during winter the polar cap grows again and the dark regions warmed geyserlike jets of carbon dioxide gas mixed with dust and send erupts from the ice. Mars seasons aren't balanced like earth. Mars experience seasons similar to that of earth but due to its higher orbital excentricity their length is quite different.


Venus Project

Mercury Project

http://www.SolarViews.con/eng/marsvolc.html =/mars/space_missions.html

--JPul008 04:59, 13 September 2007 (UTC)JPul008


There, is a foreign world out there in our galaxy that remains mysterious in the people of Earth's eyes. Despite it being on of Earths neighbors, this mysterious land remains filled with questions for those people. However, being one of the four terrestrial planets, these "Earthlings" have invaded this land that is filled with questions waiting to be answered. There is one common question that has not been answered yet. "Could there be ANY form of life on Mars?" This question, as well as others is still being pondered upon by Earthlings, while they invade the peaceful home of what SEEMS to be nobody. Well, as it turns out, the Earthlings technology defiantly missed something during their explorations...

Until now...

Sir Marty, the ruler of this rather vast world called Mars was the first of the Martians to discover mysterious objects roaming around the world. "I cannot believe this!" he exclaimed, "Another freaking object from Earth.... These things are some pests!!!" "I wonder what they are trying to do..." Fascinated by this mysterious object, Sir Marty began to observe it. He found wheels, several computer chips, and most importantly a camera. The Earthlings were spying on THEM!! Outraged by this fact, Sir Marty captured this object on wheels and took it to his laboratory for further investigation.

Once in the privacy of his laboratories, Sir Marty decided to call upon his finest investigation team. This team consisted of 6 Martians (3 technicians & 3 scientists). The leader of this group was Dr. Mac, a Sr. scientist. Dr. Mac has the most experience of all of the scientists on Mars, but even he has not seen anything of this complexity from Earth. As Dr. Mac looked over the various parts of this mysterious object that he called "land rover", he formed an important hypothesis that jump-started the investigation for the team. Knowing that Mars was a terrestrial planet just like Earth, he figured that the Earthlings were not overly interested in what their world looked like. The were more interested in finding out whether there was any life here on Mars, just as there was on Earth. The rest of the team felt that this hypothesis was necessary, and thus began planning the next step of their inquest as to why the land rover was invading the privacy of the citizens of Mars.

"Ummmmmmm Sir Marty?? I found a few interesting gadgets over here.. Come QUICK!!" Dr. Mac had discovered the devices the Earthlings were using to "spy" on them. Attached to those devices was an antenna. "Hmmmmmmm..... this is going to allow us to get in touch with these nosy people, and see what they want" Sir Marty wasn't as enthusiastic about this plan, but at the same time he was disgusted with the number of these "rovers" roaming around on the surface of his beloved planet. Therefore, he approved of Dr. Mac's idea under one condition.

Let him do the talking....

"Sir Marty to Earthlings, come in please!"

Meanwhile, back at NASA headquarters on Earth, there was pandemonium over the transmission received from rover 324 (the captured rover). NASA administrator Sean O'Keefe took charge and answered this "mysterious" voice.

  • (E= Earth, M= Mars)

E: "NASA to Dr. Mac, we hear you loud and clear."

M: "Yessir, I, as leader of the Martain people demand an explanation for the ridiculous number of rovers from YOUR planet!!"

E: Did you say ummmm Martain people???

M: YES I did... now explain yourself, or you can kiss all of your gadgets goodbye!!!

E: Well sir, we sent our new line of space explorer rovers to your land to gather more information to answer some of our questions...

M: Questions like?????

E: Well, ironically, you answered our main question by coming in contact with us through our rover.. The people of Earth have always wondered if there were any living organisms on your planet.

M: Well, now ya know, so can you PLEASE take those damned things off of my land??

E: Well, before we do that, can you explain how you guys survive in your habitat?? I mean, after all, it is much different from our living conditions here on Earth...

M: Well Mr. O'Keefe, I supposeeeeeeee I can do that for you...

E: Good man..

M: Well, first off... Our skin is made up of a thick layer of blubber.. This allows us to cope with those subzero temperatures that you guys know of. And yes, we have seasons here on Mars, thanks to our 25 degree tilt. Our temperatures vary during our seasons, but they never peak above the 0 degree mark (C). I know you are probably thinking, with temperatures this low, its impossible for us to have water... Well... we don’t necessarily have water, but our windy conditions in the Meridiani Planum region of our world allow fluvial sediments made up of sulphate rich grains to be present on our land. This is the closest thing that we have to water, but it complies with our body chemistry.

E: Well that’s very interesting, but how do you guys live in such a low pressure atmosphere??

M: Well, again, our body structure and bodily functions make this possible... Our average surface pressure runs about 5-7mb.. From what i understand, that’s like ummmmmmmmmmmmm around 1000 millibars lower than your average pressure on Earth... Sooo maybe that'll make you think twice about actually coming here *laughs* ahem... ANYWAYS, yes our immune system makes it possible for us to live in such a thin atmosphere. However, although our atmosphere is so thin, it is composed of most of the same gases as your atmosphere. Only, carbon dioxide dominates our atmosphere.

E: Wellllllllllllllllllllll, that really clears up my questions Sir Marty... I appreciate your patience with us here at NASA.

M: Yes yes, you got your information, now i want some peace and quiet... Remover your equipment from my land PLEASEEE!!!!

E: Yes sirrrrr, will do!!



Misc. Information

  • A popular site for exploration and research
    • Why? It is the closest planet to Earth, and its atmosphere and climate are not too harsh for orbiters and rovers. Mars is a terrestrial planet (solid surface), which allows these exploration tools to roam around the planet.
  • Its average distance from the sun is 141.6 million miles
  • Orbital Speed
    • Avg: 24.077 km/s
    • Max: 26.499 km/s
    • Min: 21.972 km/s
  • Surface Temp
    • Avg: −46 °C
    • Max: −5 °C
    • Min: −87 °C

Physical Characteristics & Features

Geology: the study of physical history

  • Surface primarily composed of basalt, based on observations of lava flowing from volcanos.
  • Surface covered with many craters, polar ice caps, canyons, volcanoes and mountains
  • Reddish appearance caused by Iron (III) oxide (Fe2O3)
  • Average thickness of crust = 50km but no thicker than 125 km.
    • As a result, the crust does not deform very easily
  • Core region: about 1,480 km in radius (about half of the planets radius)
  • Consists of primarily iron and about 15% sulfur
  • Core is at least partially fluid
  • The high content of Sulfur gives the core a low viscosity (The resistance of a substance to flow.)
    • Ex. Water flows faster than molasses because it contains a lower viscosity level.

Hydrology: the study of waters distribution, uses, and conservation on a planets surface and atmosphere.

  • It is hypothesized that earlier in its history, Mars had a much denser atmosphere and thus could have had water on the surface. Currently, the atmospheric pressure on the surface of Mars is equivalent to the pressure 35 kilometers above the surface of the earth. The Martian atmosphere is mostly composed of carbon dioxide. The atmosphere on Mars is so thin that liquid water freezes or evaporates quickly.
  • The Opportunity Mars Exploration Rover found evidence for groundwater activity in the Meridiani Planum region of Mars, in the form of aeolian(wind) and fluvial sediments (river or stream) composed of sulphate-rich grains.
  • Little is known, however, about the hydrologic processes responsible for this environmental history—particularly how such extensive evaporite deposits formed in the absence of a topographic basin.
  • NASA continues to research Mars’ hydrology through programs like Opportunity Mars Exploration.

Geography: The physical characteristics, especially the surface features, of an area.

  • Mars has seasons because, like the earth, it rotates on a tilted axis of 25° while earth's is 23.5°.
  • With a diameter of 6779 kilometers (4212.2 miles), Mars is just over half of the diameter of the earth (12,742 km).
  • During a Martian winter, the size of the polar ice cap grows. During the summer, it shrinks. These polar caps are formed mostly of frozen carbon dioxide ("dry ice").
  • The summers in the southern hemisphere are warmer than the summers in the northern hemisphere.
  • Mars has latitude and longitude. Of course, 0° latitude is the equator, the dividing line between the northern and southern hemispheres, and 90° north and south are the poles. There's no observatory at Greenwich on Mars so 0° longitude is simply an imaginary line to help us locate Martian features.
  • The surface of the Red Planet has two distinct areas of topography: the Northern Lowlands and Southern Highlands. The Northern Lowlands is an area which displays the results of lava flows, sedimentary deposits and cold weather (periglacial) processes. The Southern Highlands are separated from the Lowlands by a ridge up to two kilometers high and are heavily cratered like the earth's moon.

Atmosphere: The gaseous mass or envelope surrounding a celestial body. It is retained by the celestial body's gravitational field.

  • Mars has a very thin atmosphere made mostly of carbon dioxide
  • The Vikings made the official measurements of Mars’s atmosphere.
  95.32%: carbon dioxide
  2.7%: nitrogen
  1.6%: argon
  0.13%: oxygen
  0.07%: carbon monoxide
  0.03%: water vapor
  trace: neon, krypton, xenon,
  ozone, & methane
  • Surface pressure 1-9 millibars, depending on altitude; average 7 mb.
    • Put it in perspective: (Hurricane Wilma , the strongest Atlantic Hurricane on record had a central pressure of 882mb at peak strength)
  • In 2004, researchers found small quantities of methane and ammonia in the Martian atmosphere. These discoveries are important, because methane is expected to be destroyed by sunlight in a time period of a few 100 years, and ammonia is only expected to survive for several hours in Mars’s atmosphere.

History of early observations of the Atmospehere:

  • William Herschel offered the first scientific evidence that Mars might have an atmosphere. His observations of the planet in 1783 led him to suppose that some changes he had noted were due to "clouds and vapors." Four years later, Johann Schröter arrived at the same conclusion:
    • “The spots and streaks on the surface of Mars are always changing, even from hour to hour. But that they are the same regions is shown by the fact that the same shapes and positions develop and pass away again, as one would expect of the variable atmospheric appearances occurring above a solid surface.”
  • The first substance to be positively identified in the Martian atmosphere was carbon dioxide.

Climate: the composite or generally prevailing weather conditions of a region, as temperature, air pressure, humidity, precipitation, sunshine, cloudiness, and winds, averaged over a period of time.

  • The orbit of Mars is not quite circular, it is slightly elliptical (an ellipse is a "flattened" circle). The sun is not in the center of this ellipse, but is offset to one side. As a result, there is one point in Mars' orbit where it is closest to the sun (called perihelion) and one point where it is farthest (called aphelion). Mars perihelion is measured to be 203,655,215 km and its aphelion is measured to be 249,232,432 km.

  • Mars has seasons because its axis is tilted 25.19°. Mars is at perihelion during the southern summer, making it slightly more intense than the northern summer.
  • Earth seasons vs. Martian seasons

Seasons Earth (Northern Hemisphere) in Earth days Mars (in Earth days) Spring 93 171 Summer 94 199 Fall 89 171 Winter 89 146

  • Mars also contains clouds, some CO2, others water

  • In 1999, Astronomers using NASA's Hubble Space Telescope detected a cyclonic storm system in the North Polar Region of the planet Mars. The storm is composed of water ice clouds like storm systems on Earth, rather than dust typically found in Martian storms, and is about four times the size of Texas. The storm, three times larger than any previously detected Martian spiral storm, is nearly 1100 by 900 miles in dimension. The eye of this colossal storm is approximately 200 miles in diameter. The system is larger than the planet's residual north polar ice cap, and is comparable in size to the hurricanes found on Earth.


  • Mars’ average distance from the Sun is roughly 230 million km. Its orbital period is 687 (Earth) days.
  • Mars takes twice as long as the Earth to orbit the Sun.
  • Mars days are only slightly longer than Earth days: 24 hours, 39 minutes, and 35.244 seconds.
  • A Martian year is equal to 1.8809 Earth years, or 1 year, 320 days, and 18.2 hours.


  • Two moons: Phobos & Deimos
    • Phobos {panic/fear (Greek mythology)}:
      • Discovered by Asaph Hall in 1877
      • Size: 13.4 x 11.2 x 9.2 km
      • Avg. distance from Mars: 9,378km.
      • Mass: 1.063 x 1016 kg
      • Rotation period: 24.62 Earth hours
      • Orbit period: 0.31891023 Earth days
    • Deimos {terror/dread (Greek mythology)}:
      • Discovered by Asaph Hall in 1877
      • Size: 7.5 x 6.1 x 5.2 km
      • Avg. Distance from Mars: 23,459 km
      • Mass: 2.38 x 1015 kg
      • Rotation period: 24.62 Earth hours
      • Orbit period: 1.2624407 Earth days

Life on Mars. Fact or Fiction?

  • Currently, the answer to this question would be fiction.
    • There is no solid evidence at the moment that there is actually life on the planet. It's (Mars) atmosphere conditions are also not very suitable for any form of life at the moment.
  • However, researchers have concluded that if there was ever life on Mars, then it was a "long time ago"

Works Cited