Mars 4 var en sovjetiskrymdsond som sköts upp den 25 juli1973, med en Proton K/D raket, för att utforska planetenMars. Efter en kurskorrigering den 30 juli 1973 slutade två datorer ombord att fungera, vilket ledde till att manövern för att gå in i omloppsbana runt Mars inte kunde genomföras. Den 10 februari1974 passerade rymdsonden Mars på ett avstånd av 1 844 km.
Marskorsande asteroider•Mars trojaner•Dariankalendern•Tid på Mars•Mars Society•Flashline Mars Arctic Research Station•Haughton–Mars Project•Mars to Stay•Mars flagga•Mars i fiktion•Marshavshypotesen•Caves of Mars Project
Mars 4-5.jpg Foto della sonda spaziale sovietica Mars 4 (uguale a Mars 5).
Mars Hubble.jpg NASA's Hubble Space Telescope took the picture of Mars on June 26, 2001, when Mars was approximately 68 million kilometers (43 million miles) from Earth — the closest Mars has ever been to Earth since 1988. Hubble can see details as small as 16 kilometers (10 miles) across. The colors have been carefully balanced to give a realistic view of Mars' hues as they might appear through a telescope.
Especially striking is the large amount of seasonal dust storm activity seen in this image. One large storm system is churning high above the northern polar cap (top of image), and a smaller dust storm cloud can be seen nearby. Another large dust storm is spilling out of the giant Hellas impact basin in the Southern Hemisphere (lower right).