Mercury (planet) three weeks, the Sun is almost stationary overhead, and is at its most brilliant because Mercury is at perihelion, its closest to the Sun. This prolonged exposure to the Sun at its brightest makes these two points the hottest places on Mercury. Conversely, there are two other points on the equator, 90 degrees of longitude apart from the first ones, where the Sun passes overhead only when the planet is at aphelion in alternate years, when the apparent motion of the Sun in Mercury's sky is relatively rapid. These points, which are the ones on the equator where the apparent
The Empty Planet them a newspaper so they can quickly learn the human language. They reveal the strange image is a countdown. They demand the air and the sun, saying that if it is not given to them by the end of the countdown the human race will not return. Rani realises that they don't mean 'sun and air' but 'son and heir'. It turns out that Gavin's father was an alien king, who has now died. The robots have come to take Gavin to their planet and sent the news he is a prince in the energy trace, but Gavin never received