Astronomy Picture of the Day . Ancient Volcanos of Mars . ... Credit: Malin Space Science Systems , MOC , MGS , JPL , NASA Explanation: Findings of ancient martian microbial fossils in meteorites and liquid water related features on Mars' surface are currently controversial issues. ... This synthetic color picture recorded in March by the Mars Global Surveyor spacecraft shows two of them, Ceraunius Tholus (leftmost) and Uranius Tholus. ... Publications with keywords: volcano - Mars . ...