Mercury (planet) Mercury (planet) Mercury is the smallest and innermost planet in the Solar System. Its orbital period around the Sun of 87.97 days is the shortest of all the planets in the Solar System. It is named after the Roman deity Mercury, the messenger of the gods. Like Venus, Mercury orbits the Sun within Earth's orbit as an "inferior planet", and never exceeds 28° away from the Sun. When viewed from Earth, this proximity to the Sun means the planet can only be seen near the western or eastern horizon during the early evening or early morning. At this time it
A Deepness in the Sky A Deepness in the Sky A Deepness in the Sky is a science fiction novel by American writer Vernor Vinge. Published in 1999, the novel is a loose prequel (set twenty thousand years earlier) to his earlier novel "A Fire Upon the Deep" (1992). The title is coined by one of the story's main characters in a debate, in a reference to the hibernating habits of his species and to the vastness of space. The plot begins with the discovery of an intelligent alien species on a planet orbiting an anomalous star, dubbed OnOff because for 215 of every 250