Mercury is the closest planet in the Sun and is also the smallest of the eight planets in our Solar System. It is gravitationally blocked and this rotation is unique to the solar system.





Mercury has been known to humanity since ancient times, and although its date of discovery is unknown, the first mention of the planet is considered about 3000 BC by Sumerian.


The year in Mercury is 88 days, but Mercury day is 176 earth days. Mercury almost completely closes on the Sun – also known as a gravitational blockage – and over time it slowed the rotation of the planet, almost adapting it to the orbit around the Sun.



Mercury revolves around the sun so fast that early civilizations believed they were two different stars – one that appeared in the morning and the other appeared in the evening.

Mercury facts

Mercury is the smallest planet in the solar system with a diameter of 4,879 km and is one of the five planets visible to the naked eye.



After Earth, Mercury is the second densest planet. Despite the small size, Mercury is very dense, because it consists mainly of heavy metals and rocks – the main characteristics of terrestrial planets.



Mercury is titled after the message-bearer of the Roman gods, who is also known as Hermes in Greek mythology.

This is due to the speed at which mercury circulates around the Sun and the speed with which the mercury Roman deity could deliver messages.


The mercury facts, Astronomers did not realize that Mercury was a planet until 1543 when Copernicus published his solar-focused model of the Solar System – placing the Sun as the center of the solar system, and not the previously considered center, the Earth.



The planet has only 38% of the gravity on Earth. This means that Mercury facts are unable to maintain the atmosphere it has and is instead destroyed by the solar wind.

Mercury facts
Solar winds

However, the same solar winds also bring new gases, radioactive decay, and dust from micrometeorites – complementing the atmosphere.



Mercury has no moons or rings due to low gravity and lack of atmosphere.
Once it was thought that there was a planet named Vulcan between the orbit of Mercury and the Sun – but the existence of such a planet was never found.



Mercury’s orbit is an elliptical rather than circular. According to scientists and astronomers, it has the most eccentric orbit in the solar system and the smallest round planet.



Other Mercury facts, This Planet is only the second hottest planet. Venus, though further from the Sun than Mercury actually experiences higher temperatures.


This is because Mercury has no temperature-regulating atmosphere and causes the most extreme temperature change on all planets – from -170 ° C (-280 ° F) at night to 430 ° C (800 ° F) during the day.


Mercury does not experience any seasons. Mercury’s axis has the smallest inclination on all other planets, and this causes the lack of seasons on its surface.



Mercury is the only planet that does not rotate exactly once a year – instead, it rotates three times for every two solar orbits. This is because it almost completely closes in the sun.



Mercury’s orbit was important to prove the theory of general relativity of Albert Einstein.

Planet core

Mercury has a large iron core, which is about 40% of its volume (compared to 17% of Earth’s core mass) at its center, whose radius is 1800 to 1900 kilometers1100 to 1180 miles).



The outer crust of Mercury is only 500 to 600 kilometers thick (310 to 375 miles). The outer crust (coat and crust) is 2930 kilometers (1819 miles) thick.



Mercury has a very thin atmosphere, which consists of atoms from the surface of the planet, which broke with the solar wind.

Because mercury is so hot, these atoms quickly escape into space, thanks to which the atmosphere constantly replenished.


Mercury has a poor magnetic field whose force is about 1% of the magnetic field on Earth. Only two spaceships ever visited Mercury.


It is difficult to reach the planet due to the proximity of the Sun, and the visit of the spacecraft will require 91 million kilometers towards the gravitational potential of the Sun.

Mariner 10 visited in 1974-75, flying Mercury three times and mapping half of its surface.



Mercury has more craters and impacts traces than any other planet. The surface is similar to the Moon because unlike most planets, Mercury is not geologically active and cannot “heal” from bumps with asteroids and comets. Most Mercurian craters are famous writers and artists.




What’s intriguing about Mercury facts is our lack of knowledge of some of the key details until recently.

For example, it was not until 1974 that the Mariner 10 probe recorded the first images that provided specific Mercurial surface details.


In the past few years, unexpected discoveries about the atmosphere and interior of Mercury have questioned previously accepted theories.


Now is the exciting time of discovery and a new understanding of Mercury. On March 18, 2011, the Messenger spacecraft reached the orbit around Mercury in its annual mission.



Atmosphere Of Mercury

The mercury atmosphere is so thin that it practically does not exist. In fact, approximately 1015 times less dense than the Earth’s atmosphere, Mercury’s closer to a real vacuum than any manmade vacuum ever create.


The explanation of the lack of a significant atmosphere is twofold. First, with the gravity of only about 38% of the Earth’s value, Mercury simply can not keep a lot of atmospheres.


Secondly, the close proximity of the Sun and the Sun causes it to be constantly bombarded by the solar wind, which carries most of the small amount of atmosphere.


However, just as scarce as its atmosphere, Mercury has one. According to NASA, its chemical composition is as follows: 42% oxygen (O2), 29% sodium, 22% hydrogen (H2), 6% helium, 0.5% potassium and possibly trace amounts of argon, carbon dioxide water, nitrogen, xenon, krypton, neon, calcium (Ca, Ca +) and magnesium.


A remarkable result of such a rare atmosphere is extreme temperatures occurring on the surface of the planet. At a low temperature of around -180 ° C and a high of approximately 430 ° C.


Mercury has the largest range of surface temperatures on any planet. The extreme highs on the side facing the Sun result from an inadequate atmosphere because they are unable to absorb solar radiation.



Surface Of Mercury

Until 1974, the surface of mercury remained, to a large extent, a mystery for scientists due to the close proximity of the Sun. Being so close to the Sun limits the visibility of Mercury just before dawn or just after dark.

Surface of  mercury

In these times, unfortunately, the angle in which we see Mercury from the earth moves our line of sight through a significant amount of Earth’s atmosphere, which significantly hinders our view.


However, during the three flights of Mercury in 1974, the Mariner 10 probe captured clear and delightful photographs of the surface of the planet.


Surprisingly, Mariner 10 photographed almost half of the planet’s surface during its mission! The results showed that Mercury’s surface has three important characteristics.


The first feature is the huge number of impact craters that have accumulated over billions of years. Caloris Basin is the largest of them with a diameter of 1550 km.


The third part of the surface features also tells us a lot of interest.  The important thing about buckling Mercury facts is what it implies.


The implication is that because the core of Mercury is shrinking, it is also the planet as a whole. Recent estimates show that Mercury’s diameter has decreased by more than 1.5 kilometers.