The planet Mercury has no natural satellites or rings. It is the best known lightless celestial body due to its proximity to the Sun and is also the smallest of the four solid body planets.
The remaining three are Earth, Mars and Venus. These planets are also known as interiors.
Mercury also received the classification of smaller planet of Solar System after that denominated to Pluto like planet dwarf.
Features of Mercury
Size
Mercury is the smallest of the eight planets in the Solar System and is only slightly larger (1516 mi) than the Moon which has a radius of 1,079 mi.
Density
Mercury is the second densest planet after the earth with 5.43 g / cm 3 . To justify this density experts say that the partially molten core of the planet occupies 42% of its volume. Unlike the land that occupies 17%, and has a high concentration in iron.
Atmosphere
The planet can reach large temperature changes from very high temperatures (approximately 427 ° C) to very low (approximately -170 ° C). This feature is attributed to the thinness of its atmosphere.
Its atmosphere, which is actually an exosphere (outermost layer of a planet, its composition is similar to that of outer space), is composed of helium, potassium, hydrogen and oxygen. Its creation is due to the impacts of meteorites in the surface of the planet that have taken off the atoms of the same.
Surface
The surface of the planet has many traces of craters that are due to the impact of meteorites. The reason so many meteorites hit Mercury is also due to the thinness of their atmospheric layer.
Despite the extremely high temperatures that the planet handles several studies have found ice, or a similar substance, in craters of poles that are not in sight of sunlight.
It is not yet known with certainty how the ice originated but there are two options that suggest that they may be traces of comets that have impacted or the water froze from the interior of the planet.
Thanks to studies of two spacecraft sent to the planet, Mariner 10 and Messenger, they have revealed that a significant part of the surface is volcanic. In addition they suggest of the continuous impacts of meteorites and comets the cortex could be formed by a number of considerable eruptions to Over a long period of time.
Orbit
The orbit of Mercury is characterized by being the most eccentric (very inclined and very elliptical towards the Sun), can vary from 46 to 70 million kilometers. Its orbital period (translation) is 88 days.
Phenomenon of two sunrises
In some parts of the planetary surface there is the phenomenon of two sunrises where the sun rises and then hides again to go back out and continue its journey.
This is because the orbital velocity of Mercury equals the rotational speed days before the perihelion (the closest point of the orbital to the Sun), four days after the perihelion the star returns to have a normal movement.
First studies on Mercury
The earliest known studies of Mercury come from the Sumerians, the first great civilization of Mesopotamia , Specifically between 3500 BC to 2000 BC.
Curiously, the planet received many names in that era, one of them was found in archaeological remains as MulUDU.IDIM.GU.UD. He was also associated with the god of writing known as Ninurta.
Advanced Studies
Due to the current huge challenge and the high cost of fuel (a ship would have to travel approximately 90 million kilometers), it was decided to do the relevant studies through space probes.
Mariner 10 . This ship has traveled and made studies on both Venus and Mercury, being this last three times. Although it only got data from the illuminated side of the planet, it managed to take 10 thousand images of the surface.
MESSENGER . MErcury Surface, Space ENvironment, GEochemistry and Ranging ( Surface, Space Environment, Geochemistry and Mercury Measurement ). In addition to receiving the name by the abbreviations previous Messenger also means messenger since Mercury was the messenger god of the Roman mythology.
This probe was launched in 2004 and entered the orbit of the planet on March 18, 2011. Its observation period lasted one year. Studies of the elements present in the craters were made and a global map of the planet was created, thus obtaining images never seen before, in total were 250,000 photos.
In April of 2015 the NASA finished the mission of the ship by means of a controlled impact of the ship with the planet.
BepiColombo . It is a future mission to the planet and the first of the European Space Agency (ESA) in collaboration with the Japanese Space Exploration Agency (JAXA).
It will be made up of two ships, the Mercury Planetary Orbiter (MPO) and the Mercury Magnetospheric Orbiter (MMO). The mission will be launched in 2018 and scheduled to arrive in Mercury in January 2024.
The objectives of this expedition will be to gather more information about the planet (form, interior, geology, composition and craters), atmosphere (exosphere), the origin of the magnetic field and the structure and dynamics of the magnetosphere.
The center of operations will be at the ESOC (European Space Operations Center) located in Darmstadt, Germany. The center of scientific operations will be located at ESA's European Center for Space Astronomy.
Magnetosphere
Mercury is after the earth the second planet with a high magnetic field, considering that it is smaller than the earth is believed that this characteristic is due to the possibility of a molten nucleus.
Bibliography
- Choi, C. Q. (November 30, 2016). Planet Mercury: Facts About the Planet Closest to the Sun . Retrieved from Space: space.com.
- Goldstein, R. M. (1971). Radar observations of Mercury.
- Hubbard, W.B. (1984). Planetary interiors. Van Nostrand Reinhold Co., 1984, 343 p.
- JHU / APL. (1999-2017). Messenger: Mercury and Ancient Cultures . Retrieved from"Messenger: messenger-education.org".
- Ness, N.F. (1979). The magnetosphere of Mercury. In Solar System Plasma Physics. Volume 2-Magnetospheres (Pp. 183-206).
- (1997). Mercury: Magnetic field and magnetosphere. In J. Shirley, & R. W. Fairbridge, Encyclopedia of Planetary Science (Pages 476-478).
- Slavin, J. (2004). Mercury's magnetosphere . Retrieved from Science Direct: sciencedirect.com.