Solstice And Season's Eclipse . ... This celestial event is known as a solstice, marking the beginning of Summer in the Southern Hemisphere and Winter in the North. But this year, the solstice will be followed, on December 25th, by another geocentric celestial event -- the last eclipse of the millennium ! The Christmas day eclipse will only be a partial one as the silhouetted disk of the Moon obscures the Sun's edge. ... NASA Web Site Statements, Warnings, and Disclaimers . ...