'Blueberries' and 'Popcorn'

This view from the microscopic imager on NASA's Mars Exploration Rover Opportunity shows a type of light-colored, rough-textured spherules scientists are calling "popcorn" in contrast to the darker, smoother spherules called "blueberries." The spherules seen here are on the part of a rock named "Bylot" indicated in a panoramic camera image (see PIA06777). This magnified view confirmed the existence of blueberries partially coated in the popcorn material. This mosaic was assembled from four microscopic imager frames taken on sol 199 (Aug. 15, 2004). The yellow rectangle indicates the portion of this view shown in a tighter view (see PIA06779).