1989 Event U.S.S.R.'s Phobos II enters Martian orbit 1988 Event U.S.S.R. launches Phobos II for Martian orbit 1988 Event Soviet Union launches Phobos 1 to probe Martian moon (unsuccessful) 1877 Event Asaph Hall discovers Mars' moon Phobos 1877 Event Phobos (Martian satellite) discovered (A Hall) 1829 Birthday Asaph Hall, discovered satellites of Mars, Phobos and Deimos
