In the third part of Gulliver’s Travels, Jonathan Swift described the imaginary land of Laputa inhabited by scientists alone. Among their discoveries, Swift described two moons of Mars not yet discovered in his time. The great astronomers immediately headed down the path of literary predictions but they were all disappointed. They thought Mars had no moons but they were wrong. During the opposition between Earth and Mars on 11 August 1877, a professor of the United States Naval Observatory in Washington Asaph Hall looked up to the sky through the then world’s most powerful 24-inch refractor telescope. And the telescope delivered. The professor noticed a faint star over a distance of three diameters off the planet. In a few days, there happened to be two stars and these were the elusive moons of Mars. Hall named them Phobos and Deimos, which mean “Fear” and “Terror” in Greek. These were the sons of the Greek God of War Ares who is the same as the Roman Mars.
On August 11, 1877, Deimos, the moon of Mars, was discovered