HOW MANY NATURAL SATELLITES DOES MERCURY HAVE? - SCIENCE - 2025

The planet Mercury has no natural satellites and no rings. It is the best known lightless celestial body due to its proximity to the Sun and it 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.

The first known studies about Mercury come from the Sumerians, the first great civilization of Mesopotamia, specifically between 3500 BC to 2000 BC

Interestingly, the planet received many names at that time, one of them was found in archaeological remains such as MulUDU.IDIM.GU.UD. He was also associated with the god of writing known as Ninurta.

Mercury was also classified as the smallest planet in the Solar System after Pluto was named a dwarf planet.

Mercury Characteristics

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 Earth at 5.43 g / cm ³. To justify this density, experts say that the core, partially melted, of the planet occupies 42% of its volume. Unlike the land that occupies 17%, and has a high concentration of iron.

Atmosphere

The planet can reach large changes in temperature, going from very high temperatures (427º C approximately) to very low (-170º C approximately). This characteristic is attributed to the thinness of its atmosphere.

Its atmosphere, which is really an exosphere (the outermost layer of a planet, its composition is similar to that of outer space), is made up of helium, potassium, hydrogen and oxygen. Its creation is due to the impacts of meteorites on the surface of the planet that have detached the atoms from it.

Surface

The surface of the planet has many crater tracks that are due to the impact of meteorites. The reason so many meteorites hit Mercury is also due to the thinness of its atmospheric layer.

Despite the extremely high temperatures that the planet handles, several studies have found the presence of ice, or a similar substance, in craters at the poles that are not in view of sunlight.

It is not yet known for sure how the ice originated, but there are two options that suggest that it could be traces of comets that have impacted or the water froze inside the planet.

Thanks to studies of two space probes sent to the planet, Mariner 10 and Messenger, they have revealed that an important part of the surface is volcanic, in addition to suggesting the continuous impacts of meteorites and comets, the crust could be formed by a number of considerable eruptions at 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), it can vary from 46 to 70 million kilometers. Its orbital period (translation) is 88 days.

Two sunrise phenomenon

In some parts of the planetary surface there is the phenomenon of two sunrises where the Sun rises and then hides again to rise again and continue its journey.

This is because the orbital speed of Mercury equals the speed of rotation days before perihelion (the closest point of the orbital to the Sun), four days after perihelion the star returns to normal motion.

Advanced Studies

Due to the enormous current challenge and the great cost in terms of fuel (a ship would have to travel approximately 90 million kilometers) it has been decided to carry out the pertinent studies through space probes.

Mariner 10

This ship has traveled and made studies on both Venus and Mercury, the latter being three times. Although it only obtained data from the illuminated side of the planet, it managed to take 10,000 images of the surface.

MESSENGER

MErcury Surface, Space ENvironment, GEochemistry and Ranging (Surface, Space Environment, Geochemistry and Measurement of Mercury). In addition to receiving the name from the previous acronym Messenger also means messenger since Mercury was the messenger god of 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 carried out and a global map of the planet was created, thus obtaining images never seen before, in total there were 250,000 photos.

In April 2015 NASA ended the mission of the spacecraft through a controlled impact of the spacecraft with the planet.

BepiColombo

It is a future mission to be carried out to the planet and the first of the European Space Agency (ESA) in collaboration with the Japan Space Exploration Agency (JAXA).

It will be made up of two spacecraft, the MPO (Mercury Planetary Orbiter) and the MMO (Mercury Magnetospheric Orbiter), the mission will be launched in 2018 and is scheduled to arrive at Mercury in January 2024.

The objectives of this expedition will be to collect more information about the planet (shape, interior, geology, composition and craters), about the atmosphere (exosphere), the origin of the magnetic field and the structure and dynamics of the magnetosphere.

The operations center will be at the ESOC (European Space Operations Center) located in Darmstadt, Germany. The science operations center will be located at ESA's European Center for Space Astronomy.

Magnetosphere

Mercury is the second planet after earth with a high magnetic field, taking into account that it is smaller than earth it is believed that this characteristic is due to the possibility of a molten core.

Bibliography

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4. JHU / APL. (1999-2017). Messenger: Mercury and Ancient Cultures. Retrieved from Messenger: messenger-education.org.
5. Ness, NF (1979). The magnetosphere of Mercury. In Solar System Plasma Physics. Volume 2-Magnetospheres (pp. 183-206.).
6. (1997). Mercury: Magnetic field and magnetosphere. In J. Shirley, & RW Fairbridge, Encyclopedia of Planetary Science (pp. 476-478).
7. Slavin, J. (2004). Mercury's magnetosphere. Obtained from Science Direct: sciencedirect.com.