Explanation: What could cause rectangular ridges on Mars? As data flows in from the two spacecraft currently orbiting Mars, surface structures are seen that are not immediately understood. These structures pose puzzles that planetary geologists are eager to solve, as they might provide clues to past processes that have shaped Mars over billions of years. On the right of the above image is an unusual array of ridges first spotted in Mariner 9 data in 1972. A ridge wall runs for about 5 kilometers. Two competing progenitor theories include hardened sand dunes and once-molten rock that seeped through surface cracks and cooled. Dubbed "Inca City" for their resemblance to stone walls of an ancient Earth civilization, the new Mars Global Surveyor images now show them to be part of a larger circular pattern, indicating an origin possibly related to the impact crater. (Non-natural origin hypotheses are not invoked by conservative scientists unless clear indications exist that natural processes could not work.)

<<  Oktyabr'  >> Pn Vt Sr Cht Pt Sb Vs   1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31       1995   1996   1997 1998   1999   2000 2001   2002   2003 2004   2005   2006 2007   2008   2009 2010   2011   2012 2013   2014   2015 2016   2017   2018 2019   2020   2021 2022   2023   2024

Yanvar' Fevral' Mart Aprel' Mai Iyun' Iyul' Avgust Sentyabr' Oktyabr' Noyabr' Dekabr'

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.

Publikacii s klyuchevymi slovami: Mars - Mars Publikacii so slovami: Mars - Mars
Sm. takzhe: Ledyanye oblaka nad Krasnoi planetoi Dolina Marinera: Bol'shoi kan'on na Marse Mars: sputnik, kratery i vulkany Dvizhenie Marsa Leopardovye pyatna na marsianskih kamnyah Ten' marsianskogo robota Mesto posadki "Ares-3" Vse publikacii na tu zhe temu >>