  | 
          
            This is a file from the  Wikimedia Commons. Information from its  description page there is shown below.  Commons is a freely licensed media file repository.  You can help. 
           | 
         
        
        
       
        
         
          
           | Description | 
           169384main pia09189-330.jpg
             English: NASA   http://www.nasa.gov/mission_pages/MRO/multimedia/pia09189.html 
              Ridges as Evidence of Fluid Alteration  Tectonic fractures within the Candor Chasma region of Valles Marineris, Mars, retain ridge-like shapes as the surrounding bedrock erodes away. This points to past episodes of fluid alteration along the fractures and reveals clues into past fluid flow and geochemical conditions below the surface.  
             
            | 
          
          
           | Date | 
           2007-02-18 (original upload date) | 
          
          
           | Source | 
           Transferred from  en.wikipedia; transferred to Commons by  User:Mike Peel using  CommonsHelper. | 
          
          
           | Author | 
           Original uploader was  Rickyjames at  en.wikipedia | 
          
          
           Permission ( Reusing this file) | 
           
             PD-USGOV-NASA. 
            | 
          
         
         
         Licensing 
        
         
          
           | Public domainPublic domainfalsefalse | 
          
         
         
          
             | 
           This file is in the  public domain because it was solely created by  NASA. NASA copyright policy states that "NASA material is not protected by copyright unless noted". (See  Template:PD-USGov,  NASA copyright policy page or  JPL Image Use Policy.) | 
           
            
            | 
          
         
         
          
           | 
            
            | 
           Warnings:
             - Use of  NASA logos, insignia and emblems are restricted per US law  14 CFR 1221.
 
             - The NASA website hosts a large number of images from the  Soviet/ Russian space agency, and other non-American space agencies. These are not necessarily in the public domain.
 
             - Materials based on  Hubble Space Telescope data may be copyrighted if they are not explicitly produced by the  STScI.  See also {{ PD-Hubble}} and {{ Cc-Hubble}}.
 
             - The  SOHO (ESA & NASA) joint project implies that all materials created by its probe are copyrighted and require permission for commercial non-educational use.  
 
             - Images featured on the  Astronomy Picture of the Day (APOD) web site may be copyrighted.  
 
             
            | 
          
         
         
        
       File usage
       
        The following pages on Schools Wikipedia link to this image (list may be incomplete):
        
        
       
      SOS Children aims to make Wikipedia suitable for young learners. SOS Childrens Villages helps more than 2 million people across 133 countries around the world. Would you like to sponsor a child?