Is Mars an angry planet?
Orbit: 227,940,000 kilometers (65,438+0.52 astronomical units) from the sun.
Planet diameter: 6794 km
Quality: 6.42 19e23
Mars (Greek: Ares) is called the God of War. This may be due to its bright red color; Mars is sometimes called the "red planet". Interesting note: Before the Greeks, the ancient Romans once offered sacrifices to Martians, who were a god who seldom talked about agriculture. The aggressive Greeks regarded Mars as a symbol of war, and the name of March also came from Mars.
Humans have known about Mars since prehistoric times. Because it is considered to be the best place for human beings to live in the solar system (except the earth), it is loved by science fiction writers. But it is a pity that Lowell "saw" the famous "Canal" and other things, just like the princesses of Barsoumian, are all fictitious.
The first exploration of Mars was carried out by Mariner 4 in 1965. Several attempts were made, including two Viking planes (left) in 1976. Then, after a lapse of 20 years,1July 4, 997, the Mars Pathfinder finally landed on Mars (right).
The orbit of Mars is very elliptical. Therefore, where the sun shines, the temperature difference between perihelion and aphelion is nearly 30 degrees Celsius. This has a great influence on the climate of Mars. The average temperature on Mars is about 2 18K(-55℃, -67F), but it has a span from 140K(- 133℃, -207F) in winter to nearly 300K(27℃, 80F) in summer. Although Mars is much smaller than the earth, its surface area is equivalent to the land area of the earth's surface.
Besides the earth, Mars is a solid surface planet with the most interesting terrain. There are some spectacular terrains here:
-Mount Olympus: It is 24 kilometers (78,000 feet) from the earth's surface and is the largest mountain range in the solar system. Its base is more than 500 kilometers in diameter and is surrounded by cliffs as high as 6 kilometers (20,000 feet) (right);
-Tharsis: a huge bulge on the surface of Mars, with a width of about 4,000 kilometers and a height of 10 kilometers;
Valles Marineris: a group of canyons with a depth of 2 to 7 kilometers and a length of 4,000 kilometers (the title is as follows);
-Hellas Planitia: an impact crater with a depth of over 6,000 meters and a diameter of 2,000 kilometers in the southern hemisphere.
There are many ancient craters on the surface of Mars. But there are also many newly formed valleys, ridges, hills and plains.
In the southern hemisphere of Mars, there is a curved circular highland similar to that on the moon (left). On the contrary, most of its northern hemisphere consists of newly formed low-level plains. The formation process of these plains is very complicated. There is a huge height change of several kilometers on the north-south border. The reasons for the huge difference between the North and the South and the drastic changes in the border areas are still unknown (some people speculate that this is due to the huge force generated by the increase of extraterrestrial objects). Recently, some scientists began to wonder whether those steep mountains were in their original places. This question will be answered by the "Mars Global Explorer".
The internal situation of Mars is inferred only from its surface information and a large number of related data. It is generally believed that its core is composed of high-density substances with a radius of 1700 km; Wrapped in a layer of lava, thicker than the earth's mantle; The outermost layer is a thin shell. Compared with other solid planets, the density of Mars is lower, which indicates that the iron (magnesium and iron sulfide) in the core of Mars may contain more sulfur.
Like Mercury and the Moon, Mars lacks active plate movements; There is no indication that there has been crustal translation on Mars, which can cause mountains with as many folds as the earth. Because there is no lateral movement, the giant hot zone under the crust is stationary relative to the ground. Coupled with the slight gravity on the ground, it led to the Taris uplift and huge volcano. However, no signs of volcanic activity have been found recently. Although Mars may have had many volcanic movements, it seems that there has never been any plate movement.
There have been floods on Mars and some small rivers on the ground (right), which clearly proves that many places have been eroded. In the past, there was clean water on the surface of Mars, and there might even be great lakes and oceans. But these things seem to have only existed for a short time, estimated to be around 4 billion years ago. (barres Maneri was not formed by running water. It is caused by the extension and impact of shells, accompanied by Tarsis uplift).
In the early days of Mars, it was very similar to Earth. Like the earth, almost all the carbon dioxide on Mars has been converted into carbonaceous rocks. However, due to the lack of plate movement of the earth, Mars can't recycle carbon dioxide into its atmosphere again, so it can't produce significant greenhouse effect. Therefore, even if it is pulled to the same distance from the sun as the earth, the temperature on the surface of Mars is still much colder than the earth.
The thin atmosphere of Mars is mainly composed of carbon dioxide (95.3%), nitrogen (2.7%), argon (1.6%), trace oxygen (0. 15%) and water vapor (0.03%). The average atmospheric pressure on the surface of Mars is only about 7 millibar (less than 1% on the earth), but it changes with the height, reaching 9 millibar in the deepest part of the basin and only 1 millibar at the top of Olympus. But it is enough to support hurricanes and big storms that occasionally sweep the whole earth. Although the thin atmosphere of Mars will also produce greenhouse effect, these can only raise its surface temperature by 5K, which is far lower than the temperature of Venus and the Earth as we know it.
The poles of Mars are permanently covered with solid carbon dioxide (dry ice). The structure of this ice sheet is layered, which is formed by the alternating overlapping of ice layers and the change of carbon dioxide layers. In the summer in the north, carbon dioxide is completely sublimated, and the rest is the ice water layer. Since the carbon dioxide in the south has never completely disappeared, we can't know whether there is ice under the ice in the south (left). The reason for this phenomenon is unknown, but it may be that the long-term change of the angle between the equatorial plane of Mars and its orbit leads to climate change. Maybe there is water deeper under the surface of Mars. This change in polar cover caused by seasonal changes has changed the pressure on Mars by about 25% (measured by Viking).
However, recent observations through the Hubble telescope show that Viking's environment at that time was not typical. The atmosphere of Mars now seems colder and drier than that detected by Viking (see STScI website for details).
Viking tried to do an experiment to determine whether there is life on Mars, but the result was negative. But optimists point out that only two samples are qualified, and they are not from the best place. Future Mars explorers will continue to do more experiments.
A small meteorite (SNC meteorite) is thought to come from Mars.
1On August 6th, 996, David Mackay and others claimed that the composition of organic matter was first discovered in Martian meteorites. The author even said that this ingredient, together with some other minerals obtained from meteorites, can be a proof of the existence of ancient microorganisms on Mars. (left? )
Such an amazing conclusion does not lead to the conclusion that aliens exist. Since David Zhu put forward his viewpoint, some opponents' research has also been published. But any conclusion should be "reasonable and well-founded". There are many things to be done before the conclusion is announced with complete certainty.
There is a large area of weak gravity in the tropical region of Mars. This is an unexpected discovery when the global Mars probe entered the orbit of Mars. They may have been left behind when early shells disappeared. This may be very useful for studying the internal structure of Mars, past atmospheric pressure and even the possibility of ancient life.
Mars is easy to see with the naked eye in the night sky. Because it is close to the earth, it looks very bright. Mike Harvey's planet search map shows the positions of Mars and other planets in the sky. More and more details and better charts will be discovered and completed by astronomical programs such as Starlight.
The satellite of mars.
Mars has two small near-earth satellites.
Satellite distance (km), radius (km), mass (kg), date of discovery by discoverer.
Phobos 900011.08e16 Hall 1877.
Phobos 23000 6 1.80 e 15 hall 1877
More websites about Mars, Phobos and Phobos.
More photos of Mars
The first photos from the Mars global probe.
Selected pictures of Mars Pathfinder
Is there life on Mars?
Information and pictures are from NASA GFSC (JSC has mirror sites).
The exploration of ancient life on Mars: traces of life activities may exist on the Martian meteorite ALH8400 1 produced by Kai et al. was pre-released.
From LANL
Is there life on Mars? An index about this news.
More about my homepage about Martian meteorites.
Mars meteorites show that signs of life come from the earth, not Mars.
There is life on Mars! Dr Gilbert v Levin's another viewpoint based on the return result of the Viking spacecraft.
The question about Martian meteorites comes from LPI.
SNC meteorite
"Martian meteorite" information provided by JPL Ron bulke (a lot of pictures)
From Arizona State University.
From LANL
From JPL
From RPIF
Start with StarDate.
From RGO
From TPS
From NASA Space Company.
Welcome to Mars, provided by the American Museum of Natural History.
Mars: A History of Observation and Exploration, by William Sheehan (an excellent book)
Geological history of Mars
The surface of Mars is provided by LANL.
Volcanoes on Mars are provided by LANL.
Clouds on Mars are provided by LANL.
From NSSDC
A Martian dust storm was provided by HST.
Atlas of Mars is provided by Viking's orbital camera (you can see high-definition pictures of the whole surface of Mars! )
Mars probe, providing photos of anywhere on Mars.
PDS astronaut Mars probe
The special issue of Mars is provided by Marin Space Science System.
About the connection with Mars
Contact with Mars is now written by Hardtmuth Rohmert.
Today's Mars: html~ 100k gif
Pictures provided by the Viking lander.
The climate of Mars
Meteorological data (and some pictures) provided by Viking lander
The daily weather report of Mars is provided by the radio communication team of Mars Global Surveyor in Stanford.
Pictures of Mars (Outer Wall Super Card Library)
Quotation of Martian special words
Mars perspective, providing the latest related pictures.
Percival Lowell, the earliest author of Mars, wrote it on 1895.
Explore Mars
The Mars Pathfinder brought the latest images of its surface.
Sponsor of Planetary Research Office and Materials Research
Explore the center of Mars
Chronology of Mars, an electronic news bulletin on Mars exploration provided by JPL.
The Basic Principles of Exploring Mars was written by Dr. Wanke Duke of NASA.
Study the past life of Mars in order to explore it.
Mars launch mission sequence, that is, the catalogue of Mars exploration missions.
Mars perspective, information provided by Mars pathfinders for amateur or professional observers to communicate.
Exploring Mars, news provided by LPI.
Rock 7, a typical Martian drifter.
The "face" on Mars:
Fact sheet provided by NASA.
Specific analysis provided by MSSS (copy is also available at LANL).
A teacher's guide to the appearance of Mars written by Sally Stephens.
"Happy face" picture provided by MSSS.
MGS picture, amazing page, doesn't look like a face at all.
Literary and artistic works about Mars:
Mars in the eyes of the earth; Science fiction.
Mars magazine, science fiction about Mars.
Princess Mars mythology of edgar rice burroughs
Edgar rice burroughs's god of war.
Edgar rice burroughs's Mars Army.
Savia, a Martian girl from edgar rice burroughs.
Star Wars in herbert george wells
Ray bradbury's study guide to the chronicle of Mars
Other reference materials
More contact with Mars
Unknown point
Why is there such a big difference between the perihelion of Mars? Why are the atmospheric hoods near the North and South poles different?
Are there any active volcanoes on Mars?
What makes the eroded place on Mars look so similar to the riverbed on Earth?
How much groundwater is there on Mars?
Mars is considered to be the first on the list of planets that are most likely to have life. The vikings found no signs of life on it. But they only tested two independent areas. Will there be life in other unexplored areas, or will there be life on Mars at some time in the past? Recent evidence about meteorites needs to be confirmed. Many investigations and studies will bring results.
The prospect of exploring Mars is more optimistic than other planets. NASA's Mars Global Explorer is carrying many scientific instruments from unfortunate Mars observers and is working in its orbit. The lander carried by the Mars Pathfinder successfully landed on Mars on July 4th, 1997. The third group of explorers, Russia's Mars 96, failed to launch. 1998 has implemented some other exploration plans, but in Russia, even in the United States, funds are still a big problem. The proposal of Mars Observer 1995 was not passed by Congress; No one can predict the political nature of future exploration missions. Russia's original Mars 96 (later called Mars 98) plan has been abandoned. Now Japan is planning its Mars exploration mission called "Planet B"; If the United States hesitates, maybe they will use rockets to complete the task.