... The Large Magellanic Cloud in Ultraviolet . ... Where are the hottest stars in the nearest galaxies? ... Have you ever seen an aurora? ... Many bright nebulae and star clusters in planet Earth's sky are associated with the name of astronomer Charles Messier, from his famous 18th century catalog. ... NGC 6903: The Butterfly Nebula . ... Star Size Comparisons . ... The Nebula's glowing gas surrounds hot young stars at the edge of an immense interstellar molecular cloud. Curiosity: Wheels on Mars . ...