The Dust and Ion Tails of Comet Hale Bopp . ... The blue ion tail is composed of ionized gas molecules, of which carbon monoxide particularly glows blue when reacquiring electrons . ... The blue ion tail points directly away from the Sun . The white dust tail is created by bits of grit that have come off the comet's nucleus and are being pushed away by the pressure of light from the Sun. This tail points nearly away from the Sun. ... NASA Web Site Statements, Warnings, and Disclaimers . ...