Planet Mercury: General characteristics and atmosphere
Mercury is the planet closest to the Sun (you can find general information about Mercury and other planets of the Solar System in Appendix 1) – The average distance from the Sun is 57,909,176 km. However, the distance from the sun to mercury can vary from 46.08 to 68.86 million km. Mercury’s distance to Earth is 82 to 217 million km. Mercury axis is almost perpendicular to the plane of its orbit.
Due to the slight inclination of the mercury rotation axis to the plane of its orbit, there are no seasonal changes on this planet. Mercury has no satellites. Mercury is a small planet. Its mass is the twentieth part of the mass of the earth and its radius is 2.5 times less than that of the Earth. Scientists believe that in the center of the planet there is a large iron nucleus: it represents 80% of the planet’s mass and at the top there is a mantle of rocks.
For observations from Earth, Mercury is a difficult object, since it should always be observed in the context of a evening or morning dawn under the horizon and, in addition, at this time the observer sees only half of his illuminated album. The first to investigate Mercury was the American space probe ‘Mariner-10’, which in 1974-1975. The planet overwhelmed three times. The closest approach of this space probe to Mercury was 320 km.
The planet’s surface looks like an wrinkled apple peel, it is full of cracks, depressions, mountainous chains, the highest reach 2-4 km, steep scarp, 2-3 km high and hundreds of kilometers long. In several regions of the planet, the valleys and the plains without craters are visible on the surface. The average soil density is 5.43 g / cm 3 .
In the studied Mercury Hemisphere, there is only one flat place: the heat plain. It is assumed that it is a frozen lava that sprouted from the bowels after a collision with a giant asteroid about 4 billion years ago.
General characteristics of the planet Mercury
Medium Orbital Speed, km / s – 47.87
Mass (earth = 1) – 0.0553
Weight, kg – 3.3022 * 10 23
Equatorial Radio (Earth = 1) – 0.3825
Equatorial Radio, km – 2439.7 ± 1.0
Average density, g / cm 3 – 5.427
Gravity (earth = 1) – 0.38
Rotation period around the axis, days – 58,646
Rotation period around the sun, days – 88
Inclination from Ecuador to orbit, Deg. – two
Surface temperature, ° с:
- minimum -183
- Average 67
- Maximum 427
Number of satellites – Nope
Atmosphere
Mercury’s atmosphere has an extremely low density. It consists of hydrogen, helium, oxygen, calcium vapors, sodium and potassium (fig. 1). The planet probably receives hydrogen and helium from the sun, and metals evaporate from its surface. This thin layer can be called ‘atmosphere’ only with great stretch. The pressure on the planet’s surface is 500 billion times lower than on the surface of the Earth (this is less than in modern vacuum facilities on Earth).
The maximum surface surface temperature recorded by the sensors is +410 ° с. The average temperature of the night hemisphere is -162 ° C, and the daytime temperature is +347 ° C (this is sufficient to melt lead or tin). Temperature descents due to the change of stations caused by orbit elongation reach 100 ° C on the daytime side. At a depth of 1 m, the temperature is constant and equal to +75 ° с, because the porous soil does not drive the heat well.
Organic life in Mercury is excluded.
Leave feedback