... In the Center of 30 Doradus . ... In the center of 30 Doradus lies a huge cluster of the largest, hottest, most massive stars known. The center of this cluster, known as R136, is boxed in the upper right portion of the above picture. Comet Halley and the Milky Way . ... Comet Halley is the bright white streak near this photograph's center. Comet Halley is the most famous comet in history, and returns to the inner Solar System every 76 years. ... Half Dome Rock on Mars . ...