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Mission to Mars: Project Based Learning Benchmark Lessons

De
41 pages

Mission to Mars: Project Based Learning
Benchmark Lessons
Dr. Anthony Petrosino, Department of Curriculum and Instruction, College of Education, University of
Texas at Austin
Benchmarks content author: Elisabeth Ambrose,
Department of Astronomy, University of Texas at Austin
Project funded by the Center for Instructional Technologies, University of Texas at Austin
http://www.edb.utexas.edu/missiontomars/bench/bench.html
Table of Contents


Mars as a Solar System Body 4
Place in the Solar System 4
Physical Properties and Composition 5
The Moons of Mars 7
Mars geography 8
Mountains 10
Volcanoes 10
Valleys 11
Craters 12
Surface Rocks 14

Crust Composition 16

Atmosphere composition 17

Ice caps 17

Conditions on Mars 18
Gravity 18
Atmosphere 18
Weather, winds, storms 19
Temperatures, seasons, climate 20
Length of year 22
Length of day 22
Water on Mars 22
2 Polar Ice Caps 22
Water channels 23
Surface Water 25
Previous, Current, and Future Missions to Mars 25
Mariner 4 25
Mariner 6-7 26
Mariner 9 26
Viking 1-2 27
Mars Pathfinder/Sojurner Rover 27
Mars Global Surveyor 28
2001 Mars Odyssey 29
2003 Mars Exploration Rovers 29
2005 Mars Reconnaissance Orbiter 30
Smart Lander and ...
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Mission to Mars: Project Based Learning Benchmark Lessons Dr. Anthony Petrosino, Department of Curriculum and Instruction, College of Education, University of Texas at Austin Benchmarks content author: Elisabeth Ambrose, Department of Astronomy, University of Texas at Austin Project funded by the Center for Instructional Technologies, University of Texas at Austin http://www.edb.utexas.edu/missiontomars/bench/bench.html  
   Table of Contents   Mars as a Solar System Body    Place in the Solar System    Physical Properties and Composition  The Moons of Mars     Mars geography      Mountains       Volcanoes      Valleys Craters       Surface Rocks      Crust Composition      Atmosphere composition     Ice caps         Conditions on Mars     Gravity      Atmosphere      Weather, winds, storms    Temperatures, seasons, climate Length of year     Length of day    Water on Mars      2                                                                        4 4 5 7 8 0101  11 21 41 61 71 71 81 81 81 91 02 22 22 22
     Polar Ice Caps     Water channels     Surface Water     Previous, Current, and Future Missions to Mars Mariner 4      Mariner 6-7      Mariner 9      Viking 1-2      Mars Pathfinder/Sojurner Rover   Mars Global Surveyor    2001 Mars Odyssey    2003 Mars Exploration Rovers   2005 Mars Reconnaissance Orbiter  Smart Lander and Long-Range Rover  Scout Missions     Sample Return and Other Missions  Getting to Mars       Escape velocity     Routes and travel time     Supplies: food, water, oxygen   Psychological needs/concerns   References       3                                                                    22 32 52 52 52 62 62 72 72 82 92 9203  03 13 13 13 13 33 53 53 04 
 Mars as a Solar System Body  Place in the Solar System   The Solar System. NASA/JPL.  This picture depicts the correct relative sizes of the 9 planets of the Solar System in the correct order. The planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. Mars is the fourth planet from the Sun. It is one of the four inner planets. Mars orbits at a distance of 1.52 Astronomical Units (227,940,000 km) from the Sun. One Astronomical Unit is equal to 1.496 x 108 km, the average distance from the Earth to the Sun. Astronomical Units are abbreviated A.U. Its orbit is situated between those of Earth and the Asteroid Belt.      4  Sun and planets. NASA/JPL.  This picture depicts the four gas giant planets (Jupiter, Saturn, Uranus, and Neptune), Earth, and the Sun. Earth is the tiny dot between Jupiter and the Sun. The relative sizes of the objects are to scale, with 3200 km corresponding to one pixel of the image. If the relative sizes of the planets were shrunk to be one billionth of its actual size, the Earth would be the size of a large marble (2 cm diameter), Mars would be the size of a pea (1 cm diameter), Jupiter would be the size of a grapefruit, Saturn would be the size of an orange, Uranus and Neptune would each be the size of lemons, and the Sun would be the size of a tall man.  
  The relative sizes of the Mercury, Venus, Earth, and Mars. NASA/JPL.  While it is easy to compare the relative sizes of the planets in an image, it is more difficult to compare their relative distances from the Sun. If the Solar System was shrunk to one billionth of its actual size, the Moon would be about 30 centimeters away from the Earth. The Sun would be 150 meters (one and a half football fields) away from the Earth. Mars would be 325 meters away (three football fields), Jupiter would be 750 meters away (5 city blocks), Saturn would be 1500 meters away (10 city blocks), and the nearest star would be more than 40,000 km away (twice the circumference of the Earth!) From the Earth, Mars looks like a big, reddish star. A somewhat closer view as in this image taken as the Mars   5 Climate Orbiter was approaching the planet, shows the brightly lit side of Mars that is facing the Sun.   Physical Properties and Composition  Mars has a mass of 6.4x1023 kg, or about 100 times less than the mass of Earth. It has a diameter of 6,000 km, or about half that of Earth. The surface area of Mars is about the same as the land area of Earth. There is no evidence of current plate tectonic activity or active volcanism on Mars, although there is evidence to suggest that such phenomena have been present in the past. Mars is made of an inner core with a 1700 km radius, a molten mantle, and a very thin crust that ranges from 80 km to 30 km thick in places. The planet is made mostly of iron. In fact, iron oxide (rust) on the surface of Mars is what makes the so-called “Red Planet” appear red.
 The interior of Mars. NASA/JPL.    The surface of Mars. NASA/JPL.  Because Mars is not very massive, it can retain only a thin atmosphere of mostly carbon dioxide. Carbon dioxide makes up 95.3 percent of the atmosphere, while nitrogen at 2.7 percent, argon at 1.6 percent, oxygen at 0.15 percent, and water at 0.03 percent make up the remainder. The carbon dioxide on Mars does produce a small   6 greenhouse effect that raises the temperature on the planet about five degrees. The atmosphere is thick enough to produce very large dust storms that can be seen from Earth.     A dust devil on Mars, taken by the Mars Global Surveyor. NASA/JPL.   A Martian sunset, taken by the Imager for Mars Pathfinder. NASA/JPL.  
 The red and blue colors in this Martian sunset are caused by absorption and scattering of light by dust in the atmosphere. Mars also has ice caps on both its north and south poles. The ice caps grow and shrink with the seasons, and they are made of both carbon dioxide ice (“dry ice”) and water ice. The ice caps can be seen from Earth.   Martian North Polar Cap. NASA/JPL.   The Moons of Mars  Mars has two moons named Phobos and Deimos, Greek for fear and panic. Phobos is the closer of the two, orbiting Mars 9378 km above the planet’s center. It is very small – the diameter of   7 the moon is only 22 km. It is very odd-shaped, and has a mass of just 1.1x1016 kg. It is composed mostly of carbon-rich rock and is heavily cratered. Most astronomers think that Phobos is a captured asteroid. Phobos orbits Mars very quickly. It usually rises, transverses the Martian sky, and sets twice every Martian day. The moon is also very close to Mars’ surface. Just as an airplane flying over the Earth’s equator cannot be seen above the horizon for an observer in the United States, Phobos is so close to Mars’ surface that it cannot be seen above the horizon from all points on Mars. As it orbits, it slowly spirals in towards the Martian surface. Phobos looses 1.8 meters of altitude per century, and in 50 million years it will either crash into the surface or be destroyed in the atmosphere.  
  Phobos taken from the Viking 1 Orbiter. NASA/JPL.  Deimos orbits farther out than Phobos, and it is even smaller, with a diameter of only 12.6 km and a mass of 1.8E15 kg. In fact, Deimos is the smallest known moon in the Solar System. Like Phobos, Deimos is made of mostly cratered carbon-rich rock, is very amorphous, and is thought to be a captured asteroid. Like our own Moon, Deimos orbits far enough away from Mars that it is being slowly pushed farther and farther away from the planet.     8 Deimos, taken from the Viking 2 Orbiter. NASA/JPL.  Mars Geography  Like Earth, the surface of Mars has many kinds of landforms. Some of Mars’ spectacular features include Olympus Mons, the largest mountain in the Solar System. The Tharsis Bulge is a huge bulge on the Martian surface that is about 4000 km across and 10 km high. The Hellas Planitia is an impact crater in the southern hemisphere over 6 km deep and 2000 km in diameter. And the Valles Marineris, the dark gash in Mars’ surface shown in the picture below, is a system
 of canyons 4000 km long and from 2 to 7 km deep.   Mars, taken by the Hubble Space Telescope. NASA/JPL. The white patches in the map of the Martian surface shown below are clouds and storms in Mars’ atmosphere.  Mars with clouds and storms, taken by the Hubble Space Telescope. NASA/JPL.    9 Martian Topography. NASA/JPL.  This is a map of Martian topography. In the left image, the Tharsis Bulge can be seen in red and white. The Valles Marineris is the long blue gash through the middle. In the right image, the blue spot is the Hellas impact basin. Craters can also be seen in the right image.    Mars Topography. NASA/JPL.  This image is a flat map of Mars, made from data from an instrument aboard the Mars Global Surveyor. There
 are striking differences between the northern and southern hemispheres. The northern hemisphere (top) is relatively young lowlands. It is about 2 billion years old. The southern hemisphere (bottom) consists of ancient and heavily cratered highlands, much like the surface of the Moon. It is about 4 billion years old. There is a very clean boundary between the two regions, although the reason for this sharp break is unknown. It might be due to a very large impact that occurred just after the planet’s formation. The Hellas impact basin is visible as the bright blue region on the left side of the image. The Tharsis Bulge is the bright red region on the right side. It is interesting to note that these two features are located on exact opposite sides of the planet from each other. Olympus Mons is the white spot to the left of the Tharsis Bulge.  01   Mountains  The picture below shows the Libya Montes, examples of mountains on Mars. The Libya Montes were formed by a giant impact. The mountains and valleys were subsequently modified and eroded by other processes, including wind, impact cratering, and flow of liquid water to make the many small valleys that can be seen running northward in the scene. This picture covers nearly 122,000 square kilometers (47,000 square miles).   Mountains on Mars. NASA/JPL.   Volcanoes  There is no known current active volcanism on Mars. All of the volcanoes on Mars appear to be extinct. Mars also lacks plate tectonics. Both volcanic and
 plate tectonic activity are caused by heat flowing from the interior of a planet toward the surface. Because Mars is much smaller than the Earth (about half its diameter), and is much less massive (about 1/10 the mass of Earth), the planet cooled off very quickly. There is no more heat to escape from the interior of the planet, and therefore all plate tectonic and volcanic activity has stopped. The best known volcano on Mars is Olympus Mons, which is the largest volcano in the Solar System. It is a shield volcano, meaning that it has broad, gentle slopes that were formed from the eruption of lava. It rises 24 km (78,000 ft.) above the surrounding plains – much higher than Mt. Everest here on Earth. Its base is more than 700 km in diameter, which is bigger than the state of Missouri. It is rimmed by a cliff 6 km (20,000 ft) high. The last time Olympus 1   1Mons erupted was about one billion years ago.   Olympus Mons. NASA/JPL.   Oblique view of Olympus Mons. NASA/JPL.    Elevation of Olympus Mons.   Valleys The following picture is an image of the Valles Marineris, the great canyon of Mars. It is like a giant version of the
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