Mars has two tiny moons: Phobos and Deimos, which orbit around the Red Planet. Phobos recently often flashed in the news, as scientists have concluded that this satellite is doomed and will die after some time. But what do we know about Phobos. Read on and find out.
Phobos has a shock crater, which is incredibly large compared to the size of the satellite. Named Stickney, they have 9,5 kilometers (5, 9 miles) in diameter and probably formed as a result of a collision that was so powerful that it almost destroyed Phobos. Secondary craters, which are used to determine the age of the surface of a satellite or a planet, are used by scientists to study the object. A region with fewer craters may be more eroded and older than a region with a smaller number. However, this method is not applicable to Phobos.
We all know that Phobos is doomed, but what is happening with this tiny companion now is still a matter of discussion. These grooves, which you see in the image above, were considered by scientists as the result of the collision of an object with Phobos, which resulted in the Stickney crater. However, a new study shows that these grooves are the result of gravity Mars. Phobos was supposed to collide with the surface of Mars in 30-60 million years, but now we have proof that this will never happen. Instead, the satellite will be broken and forms a ring around Mars.
Phobos is a truly dusty place. Observations with Mars Global Surveyor show that a layer of dust one meter thick covers the entire surface of the satellite. This dust has been formed as a result of erosion from impact craters over the years. You can see evidence of some of these craters in the image above.
Phobos rotates fairly close (6000 km or 3700 miles) to Mars, which is twice as close as the Moon orbit of the Earth. The satellite makes a complete revolution around the planet in 7 hours and 39 minutes and rises in the west, and sets in the east. Phobos rotates so closely to Mars that it is not visible from all points of the planet.
It is still unclear whether Phobos is a captured object, although the European Space Agency indicates its low density and possible voids inside the satellite, which means that it could be an asteroid. But there are other proofs that Phobos could have been formed in the orbit of the planet and could well have been the result of a collision of Mars with an object in the distant past.
To give a name to a celestial body requires the approval of the International Astronomical Union. MAS gives names to all planets and satellites in our Solar System and beyond. The name “Phobos” means fear. Jonathan Swift himself described two tiny companions in the story “Gulliver's Travels”. This sounds a bit strange, but Swift mentioned two Martian satellites in his book in 1726. Phobos was discovered in 1877.
It is difficult to send a spaceship
Dozens of missions were sent to Mars, but none of them landed on the surface of Phobos. Not to say that people did not try. In 1988, the Soviet Union tried to send two probes. Named Phobos-1 and Phobos-2 - both failed. Russia also tried to send a mission called Phobos-Grunt in 2011, but it was stuck in Earth orbit after launch. Fortunately for science, several missions of Mars were able to make images of a satellite, all of which you saw in this article.