What is found in Mercury



Mercury is the smallest planet and closest to the sun. Because of this proximity, it is difficult to observe from Earth, even under favorable conditions. Its maximum angular distance from the sun is only about 27 ° from the earth. Detailed images of its surface could only be obtained with space probes (e.g. Mariner 10 (1974)). Like the moon, Mercury does not have a dense atmosphere (surface pressure 10-12 mBar (according to Mariner 10)), but a weak fossil magnetic field (4 × 10-4 times the magnetic field strength of the earth) which is directed approximately parallel to its axis of rotation, but no Van Allen radiation belt. Its surface is littered with craters, mountains and plains, similar to that of the Earth's moon.

You can also find cold traps on Mercury, in grooves up to 11 km deep, into which sunlight never falls. There could be carbon or methane ice deposits there.

A particularly striking surface detail is the "Caloris Basin", a vast impact structure, at the edges of which the distortions caused by shock waves can still be seen very clearly, which were probably felt all over the planet. --------------------------------

Mercury needs 87.97 earth days to orbit the sun. It rotates around its axis once every 58.65 days; Together with its orbital period, this results in a day length of 176 earth days (rotation period / orbital period = 2/3). Until 1962, Mercury was believed to have a bound rotation. That is why the sub-solar point was chosen as the 0 meriadian on Mercury, which only fixes a degree of longitude in the case of a bound rotation. Today the crater ---------------- is used to fix the prime meridian.

The temperatures on the surface fluctuate between 70 ° and 600 ° Kelvin (night-day side).

The eccentricity of Mercury's orbit is relatively high with a value of over 0.2.

The rotation of the point closest to the sun (the perihelion) of its orbit cannot be fully explained with the help of Newton's mechanics due to orbital disturbances of the sun and the rest of the planets (especially Venus). A planet (volcano) was therefore postulated within Mercury's orbit, but it was never found. The problem was only solved by the general theory of relativity, according to which the spatial geometry is subject to bending in the vicinity of large masses (here our sun). The part of the perihelion rotation of Mercury (43 "per century) that cannot be explained according to Newtonian mechanics is a direct result of this changed geometry.

The density of Mercury is 5.42 g / cm3 - this value is similar to that of the earth, but much larger than that of the earth's moon. This is an indication (besides the magnetic field) that Mercury has a metallic core.

The escape speed is 4.25 km / sec. Together with the high surface temperatures, no dense atmosphere can hold on to Mercury. However, a higher concentration of He was found on Mercury than on the moon. This helium may have been created by radioactive decay of uranium and thorium, or it may come from the solar wind.


Physical data:

Mass [kg] 3.302 × 1023
Diameter [km] 4879.4
Mean density [kg / m3]5430
Acceleration of gravity on the surface [cm / s2]370
Escape speed at the equator [m / sec] 4250
Mean distance from the sun [AU] 0.387
Rotation period [days] 58.646225
Period of rotation [sidereal years] 0.2408467
Obliquity [°] (equator against orbital plane)0
Inclination [°] (orbit plane against ecliptic) 7.00487
eccentricity 0.20563069
Mean surface temperature [K] 440
Maximum surface temperature [K] 700
Minimum surface temperature [K] 100
Albedo 0.12
Largest surface detail Caloris Basin (1350 km diameter)
Composition of the atmosphereTraces of hydrogen and helium



Greek:'ErmhVTransliteration:HermesRoman name:Mercury

Hermes is the son of Zeus and Maia. As the fastest of the gods, he is the messenger of Zeus. In the symbolic representation, Hermes has winged shoes, a hat with wings and a magic wand. He is the god of thieves and traders. Hermes shows the dead the way to the underworld. He is named as the inventor of the bagpipes, the scale, astronomy, weights and measures, and boxing. Furthermore, he is said to have been the first to cultivate olive trees.


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