Our planet has only one known satellite, the Moon. Satellites are often called moons, referring to our own. The planet Mars has two small moons that look similar to potatoes and were discovered in the 19th century. They are so small that they are less than a quarter the size of the Moon. There is a possibility that in a few million years, they will no longer exist.
In this article we're going to reveal some of the most intriguing secrets of Mars' moons , including the characteristics and curiosities of Phobos and Deimos.
Characteristics of the moons of Mars
Mars has only two moons: Phobos and Deimos . These two irregularly shaped natural satellites orbit the planet. They are very small compared to our own moon, the Moon. Let's examine each moon individually to learn more about its characteristics:
Phobos
This satellite is only about 27 km in diameter. It orbits the planet at a distance of about 6.000 kilometers. In just 7 hours, it is able to complete a full orbit around the planet. It has a large number of craters, among which Stickney stands out. This crater is named after the wife of its discoverer. The crater has become so famous because it measures 10 km in diameter. The surface is covered with numerous grooves between 20 and 40 meters deep. These grooves are no more than 250 meters wide.
The surface of Phobos is covered in dust, reaching almost a meter in height. This is thought to be due to the constant impacts of smaller meteorites on Phobos. Furthermore, it is associated with characteristics that have piqued the curiosity of scientists, which can also be explored by investigating the curiosities of Mars and its influence on moons like Phobos.
Deimos
Let's go on to describe the other satellite of Mars. This satellite is even smaller than Phobos. It only has 12 kilometers in diameter. Like Phobos, it also has an uneven surface. Due to its low mass, gravity has not been able to round the surface. Therefore, it is said that they are shaped like potatoes.
It orbits much farther than Phobos, at a distance of about 23.500 kilometers from the center of Mars. Unlike the other moon, Deimos takes about 30 hours to complete an orbit around Mars. Its craters are not as wide; instead, they are smaller, about 2,3 km in diameter. The large number of craters gives its surface a smooth appearance at times.
The two moons of Mars always show the same face, as happens with our satellite. This is due to the tidal forces that anchor it.
The moons of Mars from the planet
Phobos orbits Mars at a very high speed. This is due to its proximity. It's one of the reasons it's able to circle the planet so quickly. From the surface of Mars, it appears to rise from west to east. Unlike Deimos, which can be seen from Mars like a star because of its size and distance, Phobos appears to rise from east and set from west. Phobos could be seen about three times a day from Mars. On the other hand, Deimos would only be visible about every two days, due to the time it takes to complete its orbit around Mars.
At the beginning of the 17th century, Johannes Kepler was able to predict that if Jupiter had four moons and Earth only one, then Mars would have two moons orbiting it. This assumption was correct, as we can see today. The problem with that theory is that Jupiter didn't have four moons, but many more. The discoveries took quite a while to be made because of their very small sizes compared to the moons of other planets.
On August 18, 1877, astronomer Asaph Hall, pressured by his wife Angeline Stickney, discovered the two moons at the Washington Naval Observatory . Today, they can be seen with an amateur telescope with an aperture of only 20 cm or more. On the day of their discovery, a 66 cm aperture telescope was required.
Origin of the moons of Mars
Several theories exist to explain the possible origin of Mars' moons. One suggests they may have originated from the asteroid belt orbiting between Mars and Jupiter. This theory could help explain their irregular shapes.
There are also other theories that suggest these natural satellites may have a similar origin to the Moon. That is, they were once part of Mars and were later ejected by meteorite impacts, leaving them in orbit. These theories relate to Martian gravity and its effects on celestial bodies, as well as the potential influence of black holes on the dynamics of the solar system.
Curiosities
We are going to list some of the most important curiosities that the moons of Mars have:
- Phobos is separated from Mars 9.380 kilometers from the center. With every century that passes, it gets 9 meters closer to the surface. This is due to the action of gravity. This means that, within 40 million years, Phobos ends up colliding with Mars.
- Unlike what happens with the Moon, these satellites do not reflect sunlight because of their size. This means that at dusk, everything is in twilight and the planet does not have any type of illumination.
- The moon Deimos is moving further and further away from the planet Mars. Each time it has a longer route and it takes more time to complete a complete revolution. In a few million years, Deimos will no longer be part of the Martian system. This will make it a drifting asteroid until it orbits another planet or roams the universe. These events would spell the end of the moons of Mars.
I hope this information helps you to know more about the moons of Mars and their curiosities. As you can see, nothing is forever, and although the time scale of the universe has nothing to do with the human scale, there is also an alpha and an omega.
