These stunning photo essays present the planets Mars, a vivid orange-red beauty rising out of the darkness, and Uranus, a shimmering blue-gray globe with mysterious coal-black rings. In both titles, there are spectacular full-color photographs, many taken by spacecraft, and carefully written, informative text. Simon presents difficult factual material in readable form, conveying a sense of wonder and adventure regarding the continued exploration of our solar system. Photographs from the Mariner and Viking space probes show close-up views of Mars, including the polar icecaps, the dusty surface, Olympus Mons, and Mars' two small moons, Phobos and Deimos. Uranus shows photographs taken by Voyager 2 Spacecraft in its sweep past the present in January 1986. Before Voyager 2, the planet was known to have five moons. According to Simon, the space probe discovered ten new moons, most about 30 miles across. Voyager also discovered two new rings made up of spinning chunks of a black unknown material. As Simon says, ""These chunks look like lumps of coal on a merry-go, round."" Simon notes that Voyager 2 is presently on its way to a meeting with Neptune in 1989. Let's hope that Simon will again be our guide.