Earth's moon is "the Moon” because it was the only one people had ever seen until 1610. That's when Galileo discovered moons orbiting Jupiter. Why did it take until 1877 for someone to find the moons of our neighbor Mars?

Moons of Mars - Facts for Kids

Here are two NASA photos showing the two Martian moons, with Phobos on the left and Deimos on the right. You can see that they are highly irregular in shape.