Mercury (planet) diagram on the right illustrates the effects of the eccentricity, showing Mercury's orbit overlaid with a circular orbit having the same semi-major axis. Mercury's higher velocity when it is near perihelion is clear from the greater distance it covers in each 5-day interval. In the diagram the varying distance of Mercury to the Sun is represented by the size of the planet, which is inversely proportional to Mercury's distance from the Sun. This varying distance to the Sun leads to Mercury's surface being flexed by tidal bulges raised by the Sun that are about 17 times stronger than the Moon's
Dark Planet the series' best. It was part of a second set of four books, which were successful enough to allow the range to continue. Dark Planet "Dark Planet" is a BBC Books adventure book written by Davey Moore and is based on the long-running British science fiction television series "Doctor Who". It features the Tenth Doctor and Martha. This one was set on a future version of Earth where society was split in half and some people stayed underground and the rest high above on land dangerously close to the Sun. This is part of the "Decide Your Destiny" series which