Mars -- the real planet1.5 AU from SunDiameter ~ ½ Earth Cold, dry planet – weak greenhouseMass ~ 1/10 Earth Max 70F summer, Min -140FDensity 3.9 gm/cm 3Period 687d ~ 2 yrsRotation 24h 37mInclination 24oAtm – thin, low densityCO2 95%N 3%Ar 2%H2O trace – clouds, ice caps
Earth and Mars Comparison Earth MarsRadius 6378 km 3397 kmDensity 5515 kg/m3 3933 kg/m3Gravity 9.8 m/s2 3.72 m/s2Year 365.25 days 686.98 daysEccentricity 0.017 0.094Day 24 hours 24 hr 39 minObliquity 23.45º 25.19º
Hubble Telescope Picture of Mars This NASA Hubble Space Telescope view provides the most detailed complete global coverage of the red planet Mars ever seen from Earth. This picture was taken on February 25, 1995, when Mars was at a distance of 65 million miles.
Atmosphere on MarsMars has a rocky, dry terrain with huge volcanoes anddeep valleys. The atmosphere is much thinner thanEarth’s and is comprised primarily of carbon dioxide andnitrogen. It’s gravity is about one-third of our own.
The surface on MarsSurface 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
Water on Mars?Sinusoidal channelsLaminated terrainIce Caps
Largest Volcano on Mars The largest volcano in the solar system is Olympus Mons. It is 624 km (374 miles) in diameter; about the same size as Arizona. The altitude of Olympus Mons is three times the altitude of the largest peak on Earth, Mt. Everest.
Gigantic Canyon Valles Marineris, or Mariner Valley, is a vast canyon system that runs along the Martian equator. Valles Marineris is 2500 miles long and reaches depths of up to 4 miles.
Gigantic Canyon For comparison, the Grand Canyon in Arizona is about 500 miles long and 1 mile deep. In fact, the extent of Valles Marineris is as long as the United States and it spans about 20 percent (1/5) of the entire distance around Mars.
Seasons on MarsLike Earth, Mars has seasonal changes but the seasons last muchlonger. In Winter, Mars’ polar ice cap can reach down to 45degrees latitude and then rapidly shrink during Spring. Dust stormsare seasonal, also, as witnessed in this Hubble image.
Earth/Mars Comparison Mars EarthDistance from Sun 141.6 Million Miles 93 Million Miles Diameter 4222 Miles 7926 Miles Length of Year 687 Earth Days 365.25 Days Length of Day 24 hours 37 minutes 23 hours 56 minutes Gravity .375 that of Earth 2.66 times that of Mars Temperature Average -81 degrees F Average 57 degrees FTemperature Range -127 C to 17 C -88 C to 58 CNumber of Moons 2 1
Mars, the god of War The planet was named after Mars, the Roman God of War, who was one of the most worshipped and revered gods in ancient Rome. The god Mars held a special place in the Roman Pantheon not only for his patronly influence, but because of the importance of military achievement in the republic and the Roman Empire.
Early conceptsBefore space exploration, Mars was considered the bestcandidate for harboring extraterrestrial life. Italianastronomer, Giovanni Schiaparelli thought he saw straightlines crisscrossing its surface. This led to the popular beliefthat irrigation canals on the planet had been constructed byintelligent beings.
Mariner missions In July of 1965, Mariner 4, transmitted 22 close- up pictures of Mars. All that was revealed was a surface containing many craters and naturally occurring channels but no evidence of artificial canals or flowing water.
Viking Landers Finally, in July and September 1976, Viking Landers 1 and 2 touched down on the surface of Mars. The three biology experiments aboard the landers discovered unexpected and enigmatic chemical activity in the Martian soil, but provided no clear evidence for the presence of living microorganisms in the soil near the landing sites.
Viking LandersAccording to scientists, Mars is self-sterilizing. They believethe combination of solar ultraviolet radiation that saturates thesurface, the extreme dryness of the soil and the oxidizingnature of the soil chemistry prevent the formation of livingorganisms in the Martian soil. The question of life on Mars atsome time in the distant past remains open.
The First RoverMars Pathfinder was the first instrumented lander and robotic rover to studythe surface of Mars. Findings from the investigations carried out by scientificinstruments on both the lander and the rover suggest that Mars was at one timein its past warm and wet, with water existing in its liquid state and a thickeratmosphere.
Mars Exploration Rovers Artist’s Concept Image: NASAThe Mars Exploration Rovers, Spirit and Opportunity, arecurrently studying how past water activity on Mars hasinfluenced the red planets environment over time.
Spirit In March 2005, Spirit studied rocks in the “Paso Robles” area that have a high sulfur content. Much of the high sulfur is contained in a hydrated iron-sulfate mineral that can only have formed in the presence of liquid water.
Opportunity Opportunity’s spectrometer and microscopic imager found that rocks near the lower slopes of Endurance Crater were affected by water both before and after the crater formed.
CuriosityNASAs Curiosity Mars RoverTo handle this science toolkit, Curiosity istwice as long and five times as heavy as Spiritor Opportunity. The Gale Crater landing siteplaces the rover within driving distance oflayers of the craters interior mountain.Observations from orbit have identified clayand sulfate minerals in the lower layers,indicating a wet history.NASAs Mars Science LaboratoryCuriosity rover, a mobile robot forinvestigating Mars past or presentability to sustain microbial life.Curiosity is being tested inpreparation for launch in the fall of2011.