12.2018 THE SEARCH FOR SACRED TEXTS “If you are dealing with antiquities, you must get your hands dirty.” EITAN KLEIN ISRAEL ANTIQUITIES AUTHORITY EXPLORE | ATLAS MARINE MARS? Ice V A S T I T A S Lomonosov 60° vvvič ankkko Kunowsky MMMiiilll ACIDALIA ARCADIA Ascuris PLANITIA PLANITIA TEMPE Planum TERRA C HRYSE 30°N Massive volcano Olympus Mons and the deep canyons of Valles PLANITIA A MAZO NIS Marineris—iconic physical fea- tures of modern Mars—had not yet formed 3.8 billion years ago. P LANITIA LUNAE Pettit PLANUM XANTHE 210° EQUATOR 240° 270° 300° TERRA 330° 0° ICY THEORY R Ancient water may have E F been frozen into thick I ice sheets blanketing the T landscape. Imprints of I R A flowing material on the A R surface would then be the G R DAEDALIA R E result of seasonal warming T and geothermal activity A M T P LANUM leading to melting. E 30°S R m nu llla R PPP s A o Ice cover rrr Newton I o ca p r s i o NOAC HIS S a P I lan B R um CCCo perrrn E AONIA ARGYRE icus N Galle U Lowell PLANITIA M Aonia 60° Planum TE RRA Arge ntea Pla num CARVED CHANNELS I ce Gullies like these, found in the In July 2018 scientists canyons of Gorgonum Chaos, argued for the existence of show clear evidence of flowing a 12-mile-wide subsurface material. Whether they were lake using radar evidence formed by water is still unknown. from a European mission. TELEVISION Ancient Mars looked very different from today’s Progress on MARS parched, crimson landscape. Around 3.8 billion years Watch season two of the docudrama series MARS. ago, the planet may have had enough surface water Episodes air Mondays at to fill an ocean or bury much of it in ice. Missions like 9/8c through December 17, on National Geographic. NASA’s Curiosity have found clues to the mystery: Did abundant water once cover the red planet? BY MATTHEW W. CHWASTYK Cap B O R E A L I S 60° Lyot Hypothetical Ocean Mie Moreux UTO PIA PLANITIA I A A B R A A R R 30° E T Baldet Peridier Cassini Antoniadi T Pasteur E ISIDIS SYRTIS Tikhonravov Eddie R PLANITIA MAJOR R E L Y S I U A PLANUM M P A L A e N 30° 60° 90° 120°EQUATOR o 150°ZZZ I T lll PPP e I iiis lll p A 0° PPP a h S n yyy llla u rrr Schiaparelli TODAY’S DESERT n m iii A um a s About 3.5 billion years ago, m B Gale u u moisture began reacting c n u aaa L lll A with iron in Mars’s powdery PPP soil, creating its red hue. Gusev E Herschel Flaugergues As solar wind eroded the A atmosphere, most water was lost to space. The rest is buried under the surface or HESPERIA A locked in polar ice caps. PLANUM I 30° R E Eridania Planitia M TERRA HELLAS PLANITIA M A R Kepler I R C T E I H E A T Planum R M E 60° Malea Barnard R O Chronium R Plan P E um T Prrromettthei PPPlllanum Cap PROLIFIC POOLS In this image from the Curi- Polar ice caps expand and osity rover, the arrangement contract with the planet’s of deposits implies that Gale seasons. It’s unknown how crater once held a lake of far they once reached. considerable depth. SOURCES: BETHANY EHLMANN, CALECH; CALEB FASSETT, NASA MARSHALL SPACE FLIGHT CENTER; MICHAEL MANGA, UNIVERSITY OF CALIFORNIA, BERKELEY; ROBIN WORDSWORTH, HARVARD UNIVERSITY; NASA/JPL, UNIVERSITY OF ARIZONA; NASA GODDARD SPACE FLIGHT CENTER; USGS ASTROGEOLOGY SCIENCE CENTER.