[{SlideShowNav}] !!!Satellite image of Baltic sea [{Image src='190fi.jpg' width='603' height='650' caption='Image courtesy of USGS. ' popup='false' alt='Satellite image of Baltic sea' class='image_left'}] [{SET customtitle='Satellite image of Baltic sea'}] \\ Ethereal swirls of grease ice appear turquoise against the midnight blue of the northern Baltic Sea in this false-color satellite image taken over the Aland Islands (red) between Finland and Sweden. The second stage of sea ice formation, grease ice consists of a viscous mix of tiny ice crystals and resembles an oil slick on the oceans surface. Wind and currents constantly shape and reshape grease ice into surreal, ghostly patterns.