Mars is the fourth planet from the Sun in our solar system. It is named after Mars, the Roman god of war (Ares in Greek mythology). Its name was chosen because of its red color, a feature that also earned it the nickname "The Red Planet". Mars has two moons, Phobos and Deimos, both are small and oddly-shaped, each possibly being captured asteroids. The prefix areo- refers to Mars in the same way geo- refers to Earth—for example, areology versus geology. (Areology is also used to refer to the study of Mars as a whole rather than ju ...

Including:

Mars - Mythology Mars - Physical characteristics
Mars - Atmosphere Mars - Geology Mars - Topography Mars - Canals Mars - Ice patches
Mars - The moons of Mars Mars - The exploration of Mars Mars - Nomenclature
Mars - Early nomenclature Mars - Modern nomenclature
Mars - Observation of Mars Mars - Appearance Mars - Martian meteorites Mars - Life on Mars Mars - The Mars flag Mars - Mars in fiction

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See also:

Mars, Mars - Mythology, Mars - Physical characteristics, Mars - Atmosphere, Mars - Geology, Mars - Topography, Mars - Canals, Mars - Ice patches, Mars - The moons of Mars, Mars - The exploration of Mars, Mars - Nomenclature, Mars - Early nomenclature, Mars - Modern nomenclature, Mars - Observation of Mars, Mars - Appearance, Mars - Martian meteorites, Mars - Life on Mars, Mars - The Mars flag, Mars - Mars in fiction

Read more here: » Mars: Encyclopedia II - Mars - Physical characteristics

The red, fiery appearance of Mars is caused by iron oxide (rust) on its surface. Mars has only a quarter the surface area of the Earth and only one-tenth the mass, though its surface area is approximately equal to that of the Earth's dry land because Mars lacks oceans. The solar day (or sol) on Mars is very close to Earth's day: 24 hours, 39 minutes, and 35.244 seconds. Mars - Atmosphere. Mars' atmosphere is thin: the air pressure on the surface is only 750 pascals, about 0.75% of the average on Ear ...

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Mars, Mars - Mythology, Mars - Physical characteristics, Mars - Atmosphere, Mars - Geology, Mars - Topography, Mars - Canals, Mars - Ice patches, Mars - The moons of Mars, Mars - The exploration of Mars, Mars - Nomenclature, Mars - Early nomenclature, Mars - Modern nomenclature, Mars - Observation of Mars, Mars - Martian meteorites, Mars - Life on Mars, Mars - The Mars flag, Mars - Mars in fiction

Read more here: » Mars: Encyclopedia II - Mars - Physical characteristics

Atmosphere is the general name for a layer of gases that may surround a material body of sufficient mass. The gases are attracted by the gravity of the body, and held fast if gravity is sufficient and the atmosphere's temperature is low. Some planets consist mainly of various gases, and thus have very deep atmospheres (see gas giant). Earth, Venus, Mars, and Pluto have atmospheres that envelop their surfaces, as do three of the satellites of the outer planets: Titan, Enceladus (moons of Saturn), and Triton (a moon of Neptune). ...

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An aerobot is an aerial robot, usually used in the context of an unmanned space probe. While work has been done since the 1960s on robot "rovers" to explore the Moon and other worlds in the Solar system, such machines have limitations. They tend to be expensive and have limited range, and due to the communications time lags over interplanetary distances, they have to be smart enough to navigate without disabling themselves. For planets with atmospheres of any substance, however, there is an alternative: the balloon. Flyi ...

Including:

Aerobot - Basics of balloons Aerobot - The Venus Vega balloons
Aerobot - The Mars aerobot effort
Aerobot - JPL aerobot experiments Aerobot - JPL aerobot mission concepts

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Each NASA Viking Lander carried three biological experiments to the surface of Mars in the late 1970s. These were the first experiments used specifically to look for biosignatures on another planet. The three experiments all looked for changes in chemical composition of the atmospheric gasses trapped over a sample of Martian soil as it was exposed to different temperatures, chemical substances, and other conditions. In general, the results were negative for signs of life, although one of the three experiments gave an initial po ...

Including:

Viking biological experiments - Background Viking biological experiments - The experiments
Viking biological experiments - Pyrolytic release Viking biological experiments - Labeled Release Viking biological experiments - Gas Exchange Viking biological experiments - Gas Chromatograph - Mass Spectrometer
Viking biological experiments - The Results Viking biological experiments - Scientific conclusions and ongoing debate

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The probe consisted of a lander and a lightweight (10.6 kilograms/23 pounds) wheeled robot (Rover) called Sojourner ("one in a break from journeying"), after the sometime slave, abolitionist, and women's-rights activist Sojourner Truth. Mars Pathfinder - Landing Process. Mars Pathfinder used an innovative method of directly entering the Martian atmosphere, assisted by a parachute to slow its descent through the thin Martian atmosphere and a giant system of airbags to cushion the impact.

Mars Pathfinder, Mars Pathfinder - Landing Site, Mars Pathfinder - The Probe, Mars Pathfinder - Landing Process, Mars Pathfinder - Mission, Mars Pathfinder - Mars Pathfinder Objectives, Mars Pathfinder - Mission equipment, Mars Pathfinder - Mars Pathfinder scientific objectives, Mars Pathfinder - Mission Stages: entry descent and landing, Mars Pathfinder - The Sojourner gets out, Mars Pathfinder - Sojourner's rock analysis, Mars Pathfinder - End of the mission, Mars Pathfinder - Facts, Mars Pathfinder - Bibliography on Mars

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During the entry stages these devices were used: thermic-protection shield and a big braking parachute; the usage of an altimeter radar so that the lander could establish how far it was from the surface; retrorockets to slow-down the lander during its descent; lastly, 24 airbags were opened 8 seconds before impact to muffle the landing once the lander detached from its parachute. Its landing speed wa ...

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Mars Pathfinder, Mars Pathfinder - Landing Site, Mars Pathfinder - The Probe, Mars Pathfinder - Landing Process, Mars Pathfinder - Mission, Mars Pathfinder - Mars Pathfinder Objectives, Mars Pathfinder - Mission equipment, Mars Pathfinder - Mars Pathfinder scientific objectives, Mars Pathfinder - Mission Stages: entry descent and landing, Mars Pathfinder - The Sojourner gets out, Mars Pathfinder - Sojourner's rock analysis, Mars Pathfinder - End of the mission, Mars Pathfinder - Facts, Mars Pathfinder - Bibliography on Mars

Read more here: » Mars Pathfinder: Encyclopedia II - Mars Pathfinder - Mission Stages: entry descent and landing

Sojourner's exit from the lander occurred on Sol 2. As the next sols progressed it approached some rocks which were named (by the scientists) "Barnacle Bill", "Yogi", and "Scooby Doo", after the famous cartoons. The rover made measurements of the elements found in those rocks and in the martian soil, while the lander took pictures of the Sojourner and the surrounding terrain, besides making climate observations. The Sojourner was a six-wheeled vehicle and it was 65 cm long, 48 cm wide, 30 cm tall and weighed 10.6 ...

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Mars Pathfinder, Mars Pathfinder - Landing Site, Mars Pathfinder - The Probe, Mars Pathfinder - Landing Process, Mars Pathfinder - Mission, Mars Pathfinder - Mars Pathfinder Objectives, Mars Pathfinder - Mission equipment, Mars Pathfinder - Mars Pathfinder scientific objectives, Mars Pathfinder - Mission Stages: entry descent and landing, Mars Pathfinder - The Sojourner gets out, Mars Pathfinder - Sojourner's rock analysis, Mars Pathfinder - End of the mission, Mars Pathfinder - Facts, Mars Pathfinder - Bibliography on Mars

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The first analysis on a rock started on Sol 3 with "Barnacle Bill". The Alpha Proton X-ray Spectrometer (APXS) was used to determine its composition, the spectrometer taking 10 hours to make a full scan of the sample. It found all the elements except hydrogen, which constitutes just one tenth of 1% of the rock's or soil's mass. The APXS works by irradiating rocks and soil samples with alpha particles (helium nuclei, which consist of two protons and two neutrons). The results indicated that "Barnacle Bill ...

See also:

Mars Pathfinder, Mars Pathfinder - Landing Site, Mars Pathfinder - The Probe, Mars Pathfinder - Landing Process, Mars Pathfinder - Mission, Mars Pathfinder - Mars Pathfinder Objectives, Mars Pathfinder - Mission equipment, Mars Pathfinder - Mars Pathfinder scientific objectives, Mars Pathfinder - Mission Stages: entry descent and landing, Mars Pathfinder - The Sojourner gets out, Mars Pathfinder - Sojourner's rock analysis, Mars Pathfinder - End of the mission, Mars Pathfinder - Facts, Mars Pathfinder - Bibliography on Mars

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Opportunity landed in Meridiani Planum at 354.4742°E 1.9483°S (areocentric coordinates), about 24 km downrange (east) of her intended target. Although Meridiani is a flat plain, without the rockfields seen at previous Mars landing sites, Opportunity rolled into Eagle crater, a small impact crater approximately 20 meters in diameter and it would be two weeks before she stuck a camera up to get a better look of her surroundings. On 2004 January 28, NASA announced that the landing site was being named in honor of the seve ...

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Opportunity rover, Opportunity rover - Naming of Spirit and Opportunity, Opportunity rover - Landing site: Challenger Memorial Station, Opportunity rover - Mission duration, Opportunity rover - Events and discoveries, Opportunity rover - Timeline, Opportunity rover - First panorama, Opportunity rover - First color panorama, Opportunity rover - Opportunity lands in a crater, Opportunity rover - Opportunity Ledge outcroppings, Opportunity rover - Hematite, Opportunity rover - Spherical Granules Spherules, Opportunity rover - Opportunity digs a trench, Opportunity rover - Drenched in water, Opportunity rover - First atmospheric temperature profile, Opportunity rover - Former Martian sea, Opportunity rover - Endurance Crater, Opportunity rover - Heat shield and meteorite, Opportunity rover - Moving farther south, Opportunity rover - Dug in, Opportunity rover - Astronomy, Opportunity rover - Honors, Opportunity rover - External References

Read more here: » Opportunity rover: Encyclopedia II - Opportunity rover - Landing site: Challenger Memorial Station

Exploration of Mars - Mars probe program. In 1971, shortly after Cosmos 419 failed to launch, the Soviet Union successfully sent Mars 2 and Mars 3, nearly a decade after the launch of Mars 1, all part of the Mars probe program. The Mars 2 and 3 probes each carried a lander, both arriving on Mars in 1971. The Mars 2 lander entered Mars' atmosphere at too steep an angle, causing it to crash, and the Mars 3 lander functioned for only 20 seconds after l ...

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Exploration of Mars, Exploration of Mars - Questions to explore, Exploration of Mars - Launch windows, Exploration of Mars - Early flyby probes and orbiters, Exploration of Mars - Early Soviet missions, Exploration of Mars - Mariner program, Exploration of Mars - Landers and later missions, Exploration of Mars - Mars probe program, Exploration of Mars - Viking program, Exploration of Mars - Phobos program, Exploration of Mars - Mars Global Surveyor, Exploration of Mars - Mars Pathfinder, Exploration of Mars - Spate of failures, Exploration of Mars - Mars Odyssey, Exploration of Mars - Mars Express, Exploration of Mars - Mars Exploration Rovers, Exploration of Mars - Mars Reconnaissance Orbiter, Exploration of Mars - Future Missions, Exploration of Mars - Manned missions, Exploration of Mars - Timeline of Mars exploration, Exploration of Mars - 1960s, Exploration of Mars - 1970s, Exploration of Mars - 1980s, Exploration of Mars - 1990s, Exploration of Mars - 2000s, Exploration of Mars - Future

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The Mars 2 and Mars 3 missions consisted of identical spacecraft, each with an orbiter and an attached lander; they were the first human artifacts to touch down on Mars. The orbiters' primary scientific objectives were to image the Martian surface and clouds, determine the temperature on Mars, study the topography, composition and physical properties of the surface, measure properties of the atmosphere, monitor the solar wind and the interplanetary and Martian magnetic fields, and act as communications relays to send signals from the landers ...

See also:

Mars probe program, Mars probe program - Mars 2 and 3, Mars probe program - Mars 4 5 6 and 7, Mars probe program - Later missions, Mars probe program - Phobos, Mars probe program - Mars 96, Mars probe program - External link

Read more here: » Mars probe program: Encyclopedia II - Mars probe program - Mars 2 and 3

The broad goals of the Mars Reconnaissance Orbiter are to search for evidence of water, and characterise the atmosphere and geology of Mars. Six science instruments are included on the mission along with two "science-facility instruments", which use data from engineering subsystems to collect science data. Three technology experiments are also included to demonstrate new technologies for future missions. [2] Cameras ...

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Mars Reconnaissance Orbiter, Mars Reconnaissance Orbiter - Overview, Mars Reconnaissance Orbiter - Active timeline, Mars Reconnaissance Orbiter - Mission timeline, Mars Reconnaissance Orbiter - Instrumentation, Mars Reconnaissance Orbiter - Science instrumentation, Mars Reconnaissance Orbiter - Science facility, Mars Reconnaissance Orbiter - Technology experiments, Mars Reconnaissance Orbiter - Engineering data, Mars Reconnaissance Orbiter - Structure, Mars Reconnaissance Orbiter - Power systems, Mars Reconnaissance Orbiter - Electronic systems, Mars Reconnaissance Orbiter - Navigation systems, Mars Reconnaissance Orbiter - Telecommunications system, Mars Reconnaissance Orbiter - Propulsion system

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Mars has no global geomagnetic field comparable to Earth's. Combined with a thin atmosphere, this increases the amount of ionizing radiation that reaches the Martian surface. The Mars Odyssey spacecraft carried an instrument, the Mars Radiation Environment Experiment (MARIE), to measure the dangers to humans. MARIE found that radiation levels in orbit above Mars are 2.5 times higher than at the International Space Station. Average doses were about 22 millirads per day (220 micrograys per day or 0.8 gray per year). A three year exposure to su ...

See also:

Colonization of Mars, Colonization of Mars - Similarity to Earth, Colonization of Mars - Differences, Colonization of Mars - Habitability, Colonization of Mars - Radiation, Colonization of Mars - Communication, Colonization of Mars - Possible locations for colonies, Colonization of Mars - Polar regions, Colonization of Mars - Midlands, Colonization of Mars - Valles Marineris, Colonization of Mars - Concerns

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Mars Express Orbiter - 2004. January 23 ESA announced the discovery of water ice in the South Polar ice cap, using data taken on January 18 with the OMEGA instrument. January 28 Mars Express Orbiter reaches final science orbit around Mars. March 30 A press release announces that the orbiter has detected methane in the Martian atmosphere. Although the amount is small, about 10 parts in a thousand million, it has excite ...

See also:

Mars Express Orbiter, Mars Express Orbiter - Spacecraft and subsystems, Mars Express Orbiter - Mission profile, Mars Express Orbiter - Scientific discoveries and important events, Mars Express Orbiter - 2004, Mars Express Orbiter - 2005

Read more here: » Mars Express Orbiter: Encyclopedia II - Mars Express Orbiter - Scientific discoveries and important events

MSL will be set down on the Martian surface using a new NASA high-precision entry, descent, and landing (EDL) system that will place it within ten kilometers of an intended target, in contrast to the 150-kilometer error of previous landing systems used on Mars. The rover is folded up within an aeroshell which protects it during the travel through space and during the entry at Mars. Much of the reduction of the landing precision error is accomplished by an atmospheric entry guidance algorithm, similar to that used by the astronauts returning ...

See also:

Mars Science Laboratory, Mars Science Laboratory - Mission News, Mars Science Laboratory - MSL Specifications, Mars Science Laboratory - Proposed scientific payload, Mars Science Laboratory - Mars Science Laboratory Cameras, Mars Science Laboratory - ChemCam, Mars Science Laboratory - Alpha-particle X-ray spectrometer APXS, Mars Science Laboratory - CheMin, Mars Science Laboratory - Sample Analysis at Mars Instrument Suite SAM, Mars Science Laboratory - Radiation Assessment Detector RAD, Mars Science Laboratory - Dynamic of Albedo Neutrons DAN, Mars Science Laboratory - Rover Environmental Monitoring Station REMS, Mars Science Laboratory - Power source, Mars Science Laboratory - Landing system, Mars Science Laboratory - Future of MSL

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The Orbiter had as its primary science objectives to: monitor the daily weather and atmospheric conditions record changes on the martian surface due to wind and other atmospheric effects determine temperature profiles of the atmosphere monitor the water vapor and dust content of the atmosphere look for evidence of past climate change. Specifically it was to observe and study dust storms, weather systems, clouds and dust hazes, ozone, distribution and transport of dust and water, ...

See also:

Mars Climate Orbiter, Mars Climate Orbiter - Science objectives, Mars Climate Orbiter - Spacecraft and subsystems, Mars Climate Orbiter - Mission profile, Mars Climate Orbiter - The metric mixup

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The spacecraft was launched on June 2, 2003 from Baikonur Cosmodrome in Kazakhstan, using a Soyuz-Fregat rocket, and began its inter-planetary voyage. The orbiter entered Mars orbit on December 25, 2003, and Beagle 2 entered Mars' atmosphere the same day. After repeated attempts to contact the lander failed, it was declared lost on February 6, 2004, by the Beagle 2 Management Board. On February 11, ESA announced an inquiry would be held into the failure of Beagle 2. In the meantime, the Mars Express Orbiter has started its science phase and is performing excellently a ...

See also:

Mars Express, Mars Express - Timeline, Mars Express - Mars Express instruments

Read more here: » Mars Express: Encyclopedia II - Mars Express - Timeline

Terraforming - Mars. There is some scientific debate over whether it would even be possible to terraform Mars, or how stable its climate would be once terraformed. It is possible that over geological timescales - tens or hundreds of millions of years—Mars could lose its water and atmosphere again, possibly to the same processes that reduced it to its current state. Indeed, it is thought that Mars once did have a relatively Earthlike environment early in its history, with a thicker atmosphere and abundant ...

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Terraforming, Terraforming - History of scholarly study, Terraforming - Ethical issues, Terraforming - Theoretical methods of terraforming, Terraforming - Mars, Terraforming - Venus, Terraforming - Other worlds, Terraforming - Paraterraforming, Terraforming - In fiction, Terraforming - Prose, Terraforming - Television and film, Terraforming - Miscellanea

Read more here: » Terraforming: Encyclopedia II - Terraforming - Theoretical methods of terraforming