More than 100 billion boulders may be swarming in the disk around nearby star HD 100546. In a scene thought similar to the early years of our own Solar System, ever larger rocks are growing by colliding and accreting dust as the messy business of planet formation appears to be underway.

Even the hot and cracked surface of Venus has rolling hills. Although never actually photographed from up-close, images of the Venusian surface like that shown above have been constructed in recent years by digitally merging distant photographs with height-sensitive radar. Isolated above is a 100-kilometer wide swath inside a volcanic region known as Yavine Corona.