Pluto was discovered in 1930 after noting that this planet was pulling on Neptune, over 70 years after Neptune was discovered. Pluto gets very little light. It is so far from the Sun that it gets very little of the Sun's energy.
            Period of revolution: 247.7 years. Period of rotation: 6 days, 9 hours. Main components of atmosphere: none. Known moons: 1. Temperatures: Day -184°C; Night (?).