All planets other than Mercury and Venus are known to have either at least one natural moon as the natural satellite.Despite its smaller size, Mars has two moons in comparison to Earth’s one moon, though the size of the two moons of Mars is a lot smaller than the moon of Earth. The two moons of the planet Mars are Deimos and Phobos.Deimos moon has an orbital period of around 30.3 hours around Mars. Deimos’s orbit is not exactly in the equatorial plane but a bit off, by about two degrees, which is considered quite significant by scientists. Mars moon Deimos has an orbital speed of 3,020 mph (4860.2 kph). In terms of size, both the natural moons of Mars are not larger than asteroids, but smaller than the moon of our planet Earth. As stated by NASA, Phobos is the larger moon with a diameter of 14 mi (22.5 km) while Deimos is smaller in size at around 8.1 mi (13 km). Deimos is a dark celestial body that seems to be composed of C-type surface materials, which resemble that of asteroids in the asteroid belt.Deimos and Phobos got their name based on Greek Mythology. The moon Deimos was named by astronomer Asaph Hall who discovered the moon in 1877. Deimos and Phobos were the sons of Ares, the Greek God of war.Read on for some more interesting facts about the orbital speed, orbital distance, and surface features of the moon Deimos.How were the two moons of Mars discovered?There are two Martian moons that are known to exist in our solar system. Out of the two Mars moons, Deimos has been identified as the smaller one. This Martian moon was discovered in August 1877 by a scholar who goes by the name of Asaph Hall.What is even more interesting is that these Martian moons were named after Greek mythology individuals, Ares’s sons. Ares was known as Mars, the Roman god to the Romans.Martian moon Deimos was discovered in an attempt to understand and study the red planet. As efforts were being made, Hall was able to discover this structure moving around the red planet from his naval observatory. He saw two moons of Mars and was also able to recognize their cratered surface from his naval observatory. When Hall discovered Deimos, he kept looking and eventually six days later discovered the second moon of Mars.This was the first time in years that the theory of Kepler had found any proof. These Martian moons had remained undiscovered until then because they were relatively smaller in size and moved extremely close to the red planet. Even when both the moons were discovered, the scientists took time to understand and evaluate all the information before finally sending a space mission for closer observation. After that, there were several other space missions also sent to Mars for studying the planet and its moons, Phobos and Deimos.The Formation And Composition Of DeimosThe composition of Deimos is very similar to that of asteroids that have been studied so far. Seeing the size of this moon and its structure, many scientists believe that Daimos is in fact an asteroid. They suggest that it was part of the asteroid belt between Mars and Jupiter but was thrown out of orbit.Then the gravitational force of the closest planet, in this case, Mars, pulled the asteroid into an orbit around the planet. This is because the outer asteroids present in the inner asteroid belt have similar shapes and the same composition and color.Another possibility is that the gravity of Mars enabled dust and rock particles in the solar system to accumulate closer to the planet and move in a nearly circular orbit. Certain other scientists believe that the formation of Deimos and Phobos took place in the same way as Earth’s moon, through collision. However, these are all speculations and no clear evidence has been found to indicate the precise formation of these tiny structures near Mars.From afar, the bright moons shine as bright as Venus. Space pictures indicate that Deimos was struck by meteorites several times in the past, as evidenced by its craters. Interestingly, the regolith that is spread all over the moon is, in fact, the debris or the broken specks of dust of meteorites that struck Deimos, not particles from the crate formation. Even though there are multiple craters on the surface of it, they only ever named two of them. One was named after Jonathan Swift and the other after Voltaire, both of whom were writers. Deimos is the smaller moon structure that moves Mars around in an equatorial plane.Exploring The MoonsOnce discovered, the two moons became the center of attention for most scientists. The two moons were remarkably different from Earth’s moon.Even the full moon during an eclipse on Mars appeared like tiny dots. It was discovered that Deimos moon has a radius of only 3.9 mi (6.2 km). Deimos’s orbit is 14,576 mi (23,458 km) away from the surface of Mars and it’s believed that is likely to move further away over the next century. Over the years, NASA has conducted various surveys and sent multiple missions to gather all the data possible from the moons Deimos and Phobos.The axis of their orbit is always leaning towards the red planet. This is similar to the way Earth’s moon is inclined. The regolith keeps redepositing in the cratered surface as it moves around its orbit. They named this moon of Mars after one of Ares’s sons, who is known for wreaking terror. It is still widely believed that Deimos belonged to the outer asteroid belt. Mars moon Deimos is the smallest in size among all the moons discovered so far in our solar system. The distance between Deimos’s orbit and the Sun is measured to be 142.3 million mi (229 million km).More Interesting Facts About Phobos And DeimosTheir names from Greek mythology translate into fear and terror, respectively. Both the twin brothers, Phobos and Deimos, had a close bond with one another, according to the tales. Scientists, however, after observing the orbital period and equatorial plane of both Phobos and Deimos, have felt that both these will eventually lead to destruction.Phobos is moving closer to Mars every year. As per estimates from NASA scientists, Phobos will crash into Mars somewhere around the next century. Deimos, on the other hand, is believed to be moving away from the gravitational pull of Mars. This will eventually free Deimos from its orbit around Mars and it might begin to float freely in the solar system. Alternatively, it might be captured into orbit by another celestial body. Both Phobos and Deimos are believed to have developed around the same time.Even though Phobos and Deimos were discovered with some delay, the attention they received was immense. Both Phobos and Deimos show more similarity to asteroids compared to Earth’s moon. These moons look more like asteroids due to their shape and composition. Phobos is so close to the planet that it moves around the planet at least three times each day, making it the fastest-moving moon in our solar system.The explorations that NASA engaged in resulted in capturing some brilliant images and learning more about these moons and the red planet that they orbit around. The Mars moon Deimos is interestingly showing signs of having had connections with a different celestial body in the past. This was very well comprehended by the scientists as they analyzed the uncommon gravitational tilt of this moon. It’s also possible that at some stage in the past, many ages ago, it floated free from its parent planet in the solar system. Moving too close to the equatorial plane of Mars is the same character seen in the moons of Jupiter and Saturn; it roughly shows that the moon and its planet were formed around the same time period. The orbit period of Phobos also presents evidence of this.The Appearance Of DeimosScientists believe that billions of years ago, an early moon, supposedly belonging to Phobos, hit Deimos hard enough to cause the present tilt.If this speculation is true, then the grandparent of Phobos must have been very large, much bigger than Phobos. As Deimos doesn’t move fast, it’s Phobos that comes closer to maintain the tilt of Deimos.Deimos appears to have a dark shade with craters all over it. The space images show that the moon is colored red and gray. There are a greater number of craters found towards the south pole of the moon. It is a small structure with a highly irregular shape, and it looks pretty much like a lump of heavy clay. It has got grooves all around it. The surface, however, looks smooth. This is probably because of all the dust which settled over the craters, covering the ridges and deep craters.
All planets other than Mercury and Venus are known to have either at least one natural moon as the natural satellite.
