PIA05481: Which Came First? Vug or Spherule?
 Target Name:  Mars
 Is a satellite of:  Sol (our sun)
 Mission:  Mars Exploration Rover (MER)
 Spacecraft:  Opportunity
 Instrument:  Microscopic Imager
 Product Size:  817 x 617 pixels (w x h)
 Produced By:  JPL
 Full-Res TIFF:  PIA05481.tif (349.5 kB)
 Full-Res JPEG:  PIA05481.jpg (42.63 kB)

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Original Caption Released with Image:
This image, taken by the microscopic imager onboard the Mars Exploration Rover Opportunity, shows a close-up of the region dubbed "El Capitan," which lies within the rock outcrop at Meridiani Planum, Mars. In the lower left, a spherule, or sphere-shaped grain, can be seen penetrating the interior of a small cavity called a vug. This "cross-cutting" relationship allows the relative timing of separate events to be established. In this case, the spherule appears to "invade" the vug, and therefore likely post-dates the vug. This suggests that the spherules may have been one of the last features to form within the outcrop.
Image Credit:
NASA/JPL/US Geological Survey

Image Addition Date: