The Moon That Looks Like A Rock
Above is a picture of Phobos.
While Phobos looks like a rock, it is in fact a moon of Mars.
The above graphic shows the orbit around Mars of the two Martian moons.
They spin around and around to no apparent end.
Here are some facts about Phobos–
Phobos, the largest Martian, gouged and nearly shattered by a giant impact crater and beaten by thousands of meteorite impacts, is on a collision course with Mars
Phobos, named after a messenger of the Roman god of war, is the larger of Mars’ two moons and 27 by 22 by 18 km in diameter. It orbits Mars three times a day, and is so close to the planet’s surface that in some locations on Mars it cannot always be seen.
Measurements of the day and night sides of Phobos show such extreme temperature variations that the sunlit side of the moon rivals a pleasant winter day in Chicago, while only a few kilometers away, on the dark side of the moon, the climate is more harsh than a night in Antarctica. High temperatures for Phobos were measured at -4 degrees Celsius (25 degrees Fahrenheit) and lows at -112 Celsius (-170 degrees Fahrenheit). This intense heat loss is likely a result of the fine dust on Phobos’ surface, unable to retain heat.
Phobos has no atmosphere. It may be a captured asteroid, but some scientists show evidence that contradicts this theory.
Moral of the story—Though it may look like a rock, it may in fact be a moon.
I remember the debate a few years ago about Pluto. Was it a big rock or a planet.? Was it an asteroid? I think that the final consensus was that it was an asteroid.
Now, for Mars’ moons, I think that you can have the same argument. Are they moons? Are they captured asteroids? I think that they are asteroids but in the long run it don’t matter. If you have a large enough telescope they are very cool to look at.
Pluto has been given a status in-between planet and giant rock. Plutoid is the term. really–I’m not making that up.