Abstract: Space Weather is a growing applied study of the causes and effects of radiation in Earth's space environment. These ideas are now also being extended to other planets. Together with the effects of space debris (man-made or natural) they apply constraints to the design of space missions, risks to human spaceflight, engineering of instruments and other spaceflight hardware, effects on the ground at Earth and other planets, and also affect the quality of measurements made in space. They can even affect our ability to detect extinct life on Mars. In this colloquium I will explore these issues from Mars to the edge of the solar system.