... From top to bottom, these stacked panels show the largest sunspot group in a decade in visible, extreme ultraviolet, and x-ray light. All were taken on March 29, around.. ... The Hydra Cluster of Galaxies . ... Forty years ago, on April 12, 1961, Soviet cosmonaut Yuri Alexseyevich Gagarin became the first human in space. ... At only 30 million light years distant and fully 60 thousand light years across, M51, also known as NGC 5194, is one of the brightest and most picturesque galaxies on the sky. ...