Accelerating glaciers and disintegrating ice shelves are troubling signs of major changes underway in the large polar ice sheets.  Earth observing satellites' watchful eyes in the sky capture these events as they happen and help scientists understand the processes likely for these compelling events.  Historic studies of rapid glacier retreat lend additional insight into the possible causes.  A number of these changes lie well beyond any ever recorded in human history.  With our global society's heavy investment in and cultural attachment to coastal areas, we have made ourselves vulnerable to the ice sheet's ability to change sea level.  What's going on along the icy margins of the world's ice sheets and what's in store?