Moons of Mars these 'predictions', two craters on Deimos are named Swift and Voltaire, while on Phobos there is one named regio, "Laputa Regio", and one named planitia, "Lagado Planitia", both of which are named after places in "Gulliver's Travels" (the fictional Laputa, a flying island, and Lagado, imaginary capital of the fictional nation Balnibarbi). Many of the craters on Phobos are also named after characters in "Gulliver's Travels". Asaph Hall discovered Deimos on 12 August 1877 at about 07:48 UTC and Phobos on 18 August 1877, at the US Naval Observatory in Washington, D.C., at about 09:14 GMT (contemporary sources, using the
Transit of Phobos from Mars Transit of Phobos from Mars A transit of Phobos across the Sun as seen from Mars takes place when Phobos passes directly between the Sun and a point on the surface of Mars, obscuring a large part of the Sun's disc for an observer on Mars. During a transit, Phobos can be seen from Mars as a large black disc rapidly moving across the face of the Sun. At the same time, the shadow (antumbra) of Phobos moves across the Martian surface. The event could also be regarded as a particularly quick and shallow annular solar eclipse by Phobos. A