Detailed information about Mars

Astronomical knowledge of Mars-Simple chapter

Chapter II Planetary Members of the Solar System

At present, the planetary members of our solar system mainly include Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. The early Pluto has been downgraded to a series of dwarf planets. As for whether there is a celestial body in Neptune's outer orbit that meets the definition of a planet, it has not been found yet.

The members of these planets fall into three categories. The first kind is Earth-like planet (rocky planet), which is mainly composed of silicate rocks. They are Mercury, Venus, Earth and Mars. The second kind is a woody planet (gas giant planet), which is mainly composed of hydrogen and helium. They are Jupiter and Saturn respectively. The third is the ice giant planet, which is mainly composed of ice-like solids composed of water, ammonia and methane, namely Uranus and Neptune.

We introduce these eight planets according to their distance from the sun.

The first section Earth-like planets

Earthlike planets are mainly solid planets composed of rocks and silicates. They are Mercury, Venus, Earth and Mars. It is called Earth-like planet because other planets are similar to the Earth, and they are all rock and solid planets.

2. 1. 1 mercury

See the article "Astronomical Knowledge of Mercury-A Simple Chapter"

2. 1.2 Venus

See the article Astronomical Knowledge of Venus-A Simple Chapter.

2. 1.3 Dadi

See the article Astronomical Knowledge of the Earth-A Simple Chapter.

2. 1.4 Mars

Mars is also a close neighbor of our earth, just a little farther from the sun than our orbit. Mars is different from Venus. We can see the red surface of Mars from the earth, and we can also observe the polar ice sheets and weather changes. Because the environment of Mars is quite similar to that of the Earth, Mars is more attractive to human beings.

Figure 2. 1.4 Viking 1 The mosaic image of Mars taken on February 22, 1980 shows the beautiful and huge Mariner Canyon.

2. 1.4. 1 the origin of the name of Mars

Before the Han Dynasty, Mars was not called Mars. Ancient people thought that the position of Mars was unpredictable and its brightness was unstable, so they named it Fluorescent Star.

During the Western Han Dynasty, the astronomer Sima Qian, the author of the official Historical Records, found that Mars was reddish brown from actual observation, which was linked with the theory of "five elements" and officially named Mars.

In western Roman mythology, he was named "Mars" because of his fiery red color. He is the god of war in Roman mythology-Mars mythology.

2. 1.4.2 Is there a fire on Mars?

Of course not! Seen from the earth, Mars is red, but it is not fire. Its surface is iron oxide, similar to our common "rust" color.

Figure 2. 1.4.2 True color image of Mars, taken by Rosetta in February 2007.

2. 1.4.3 How big is Mars?

Mars is slightly less than half the size of the earth. Mars is about 6779 kilometers in diameter and the earth is about 12742 kilometers in diameter. Although Mars is only half the size of the Earth, it is larger than Mercury (about 4,879.4 kilometers in diameter).

Figure 2. 1.4.3 The diameter of Mars is about half that of the Earth.

Looking at Mars from the earth's night sky, Mars can only be represented by its visual diameter. The maximum length of Mars is about 26 arc seconds, which is the extreme value of a big impact of Mars. 60 seconds is equal to 1 minute, and it takes about 30 minutes to see the sun and moon from the earth.

2. 1.4.4 Structure of Mars

Mars, like the earth, is a rocky planet. There are the core, mantle and crust, and the polar atmosphere.

There is volcanic activity on the surface of Mars, but it has been stagnant since about 3.5 billion years ago. There are plains, craters, mountains and canyons on Mars. For example, Mount Olympus is the highest mountain known in the whole solar system, and Mount Everest on earth is more than twice as high. There is also Mariner Grand Canyon, which is the largest canyon on Mars and the largest and longest canyon known in the solar system.

The surface of Mars is basically a big desert, desolate and cold. Because of the air and convection, there are often huge sandstorms sweeping the world.

Figure 2. 1.4.4 The ground of Mars

2. 1.4.5 Is there water on the surface of Mars?

Due to the harsh surface environment of Mars, there is almost no stable liquid water on the surface of Mars, but most of the water on Mars is locked in permafrost and polar cap.

In 2008, NASA's Phoenix Mars probe first discovered water in Martian soil. Then, in 20 13, NASA's Curiosity Mars probe found a lot of water in Martian soil, which indicated that Mars had enough water resources for future immigrants.

A surprise is that in July, 2065438+2008, the "Express" Mars probe of the European Space Agency discovered an underground liquid lake of Mars near the southern ice sheet of Mars, with a diameter of about 20 kilometers.

2. 1.4.6 Is there life on Mars?

This is an answer that we humans really want to know ("this is an answer that we humans really want to know" is changed to "this is a question that we humans really want to know the answer"), but unfortunately there is no! At least not yet! There is evidence that there was life on Mars in ancient times, but it is still inconclusive whether there really was life on Mars.

However, on June 6, 20 18, an amazing discovery was made. NASA announced that the rover Curiosity had found organic matter in the rocks of the ancient lake bed of Mars. This may provide important clues to the search for life.

Due to the low surface temperature, thin atmosphere and low air pressure of Mars, liquid water can not exist stably on the surface of Mars for a long time, but only underground. Because the atmosphere is thin, most of the ultraviolet rays of the sun directly illuminate the surface of Mars, so underground is a better place for life to live.

Fig. 2. 1.4.6 Life Mars described by the painter.

2. 1.4.7 Mars rotation and revolution

The rotation cycle time of Mars is very close to that of the Earth, nearly 1 day. The exact solar time of Mars is 24 hours, 39 minutes and 35.244 seconds.

Because Mars is out of the earth's orbit and farther away from the sun, its period of revolution is longer than the earth, and it takes about 687 days to go around the sun, nearly twice as long as the period of revolution of the earth.

2. 1.4.8 Future Mars Colonization

Judging from the current process of human discovery, Mars is the most suitable planet for human habitation in the solar system except the earth.

1 day of Mars is very close to 1 day of Earth. Like the earth, Mars has four seasons, polar regions and aurora, and Mars also has weather changes, such as sandstorms and tornadoes.

In the future, humans may transform Mars into the earth, so that all kinds of creatures can live independently on the surface of Mars.

Fig. 2. 1.4.8 Concept map of Mars after geochemical transformation.

A small document about Mars

The mass is about: 6417100000000 tons = 64 1765438+ 10/0/0.

The volume is about:1631800000 cubic kilometers =16365438+800 million cubic kilometers = 163 18x 10 cubic kilometers (0./kloc of the earth

The diameter is about 6779 kilometers (0.532 times that of the earth);

The rotation period is about 24.6229 hours (65438+ 0.029 times of the earth);

Period of revolution is about 686.973 days (1.88 1 times the earth);

The average temperature is about -63 degrees;

The temperature difference between day and night is about -89 degrees to -3 1 degree (measured at the Viking landing site).

About 227.9 million kilometers from the sun center;

About 78.39 million kilometers from the center of the earth;

The maximum visual magnitude seen from the earth is about -2.95438+0.

Section 2 Woodlike Planets

Wood-like planets are mainly composed of gases, sometimes called gas giant planets. They are Jupiter and Saturn, so they are called woody, so Saturn is similar to Jupiter.

Jupiter

See the next article: Astronomical knowledge of Jupiter-a simple article.

reference data

1.WJ encyclopedia

2. All data parameters are quoted from NASA-Planet Profile.

Author: Zero-degree galaxies (Astronomy Online)

Auditor: Xiao Pai

Final comment: Zero-degree galaxies (Astronomy Online)

Editing time: 2065 438+08. 7. 2-2065 438+08. 7. 6.

Review time: July 8, 20 18-September 9, 2065438+08.

Last update: 20 18 September 15 Saturday.

Note: All information and data are huge, and errors are inevitable. Please also point out the mistakes so as to correct them.