Sunset with Hale-Bopp at Keck . ... Credit Copyright: W. Keel ( U. Alabama in Tuscaloosa ) Explanation: A famous star cluster and observatory highlight this picture of Comet Hale-Bopp. Taken last week from the observatory summit of Hawaii 's Mauna Kea Volcano, the dome of the new 10-meter Keck II telescope appears silhouetted on the lower left. ... Normally sunset and clouds are to be avoided when making astronomical observations, but Comet Hale-Bopp is not a normal astronomical object. ...