... Mammatus Clouds over Nebraska . ... When do cloud bottoms appear like bubbles? ... Known to some as the Elephant's Trunk Nebula, parts of gas and dust clouds of this star formation region may appear to take on foreboding forms, some nearly human. ... Saturn in Blue and Gold . ... Long features dubbed tiger stripes are known to be spewing ice from the moon's icy interior into space, creating a cloud of fine ice particles over the moon's South Pole and creating Saturn's mysterious E-ring. ... April . ...