In boldly graphic full-bleed art and a simple text that challenges children to think and wonder, a useful concept book that explores what, actually and imaginatively, is in the apparently empty sky: sun, rain, lightning, a rainbow; birds and butterflies; kites, planes, balloons, astronauts; Pegasus, Santa Claus, ghosts, cherubim; and, ``Sad to say...soot, smog and smoke.'' The progression of color—from airy blue through several storms, a night of fireworks, another with an aurora, and back to dawn—is an especially felicitous feature of an intelligently conceived and well-designed book. (Nonfiction/Picture book. 3-7)