Recent astronomical events have afforded skywatchers an eyeful, starting with last Wednesday's magnificent harvest moon. A few days later the sun spewed giant bubbles of plasma known as coronal mass ejections (CMEs) toward the earth. CMEs can form when so-called solar filaments collapse, spilling cool, dense gas onto the sun's surface. When viewed in profile against a dark sky, such filaments are called prominences (right). As the CMEs struck the earth's magnetosphere, they triggered a luminous display of aurora, visible Sunday evening to observers in Europe and North America despite the bright light of the nearly full moon. (Early yesterday morning a shockwave passed our planet, probably the leading edge of another CME.) Asteroid enthusiasts weren't disappointed either. The Near-Earth Asteroid (NEA) 2000 RD53, discovered just last month by NASA's Near-Earth Asteroid Tracking system (NEAT), zoomed by Sunday, barely 11 times more distant than the moon. With the help of an eight-inch or larger telescope, observers can still catch a glimpse of this bright 400-meter space rock.
ABOUT THE AUTHOR(S)
Kate Wong is a senior editor for evolution and ecology at Scientific American.
Credit: Nick Higgins