The Planets of our Solar System By: Radhika Raman

MERCURY

About the Planet: Mercury Mercury is the first planet from the sun. Named by Greeks after the fleet-footed messenger god Mercury. takes approximately 88 days to orbit around the sun. Average surface temperature is around 440 Kelvins, but has risen well over into the 700’s. Mercury’s equatorial diameter is around 4879.4 km. No t known to have any satellites, or moons, or any life forms. Early astronomers believed Mercury to be two planets, referring to it as both Hermes and Apollo at different times of day. It was Pythagoras who first suggested Mercury was a single planet. merc

VENUS

About the Planet: Venus Venus is the second planet from the sun. Named after the Roman goddess Venus (Greek: Aprohdite), of love and beauty. Takes approximately 225 days to orbit around the sun. Venus has an average surface temperature of around 737 Kelvins, but often rises above that. Its equatorial diameter is around 12,103.7 km. Venus currently has no known satellites, or moons. Venus has no signs of known life. Due to its brightness, Venus is often referred to as the morning star, or the evening star.

EARTH

About the Planet: Earth Earth is the third planet from the sun. Name from the Roman goddess Tellus. Tellus was the goddess of the earth, thus giving the planet Earth its name. Takes Earth approximately 365 days to orbit around the sun. Has an average temperature of around 287 Kelvins. The equatorial diameter of the Earth is 12,756.270 km. Has one known satellite, or moon, Luna. Earth is currently the only planet known to hold life and water that is not frozen.

MARS

About the Planet: Mars Mars is the fourth planet from the sun. It got its name after the Roman god of war, Mars. This is because of its apparent red color in the night sky, also giving it the nickname of the “red planet.” It takes Mars around 687 days to complete its orbit around the sun. Mars has an average surface temperature of 210 Kelvins, and an equatorial diameter of 6, 804.9 km. Mars has two known satellites, or moons, which are Phobos and Deimos. Mars is the only planet other than Earth that scientists today think life could ever exist on.

JUPITER

About the Planet: Jupiter Jupiter is the fifth planet from the sun. It is named after the Roman god, Jupiter, who held the same place Zeus did in Greek mythology. This might have something to do with the fact that Jupiter was the greatest God to the Romans, and Jupiter, is the largest planet in the solar system. It takes Jupiter approximately 4,333 days to complete its orbit around the sun, and has an average surface temperature of 152 Kelvins. The equatorial diameter of Jupiter is 142,984 km. Jupiter has 63 known moons or satellites, with Ganymede, its largest moon, at 5,268 km in width.

SATURN

About the Planet: Saturn Saturn is the sixth planet from the sun. Saturn is named after the Roman god Saturn, known as Cronus in Greek mythology, often associated with the sickle. Saturn is the second largest planet in the solar system. Saturn’s revolutionary period is 10,756 days long. The average surface temperature of Saturn is 143 Kelvins. Saturn has an equatorial diameter of 120,536 km. Saturn has 49 confirmed satellites, or moons, with its largest moon, Titan, bigger than the planet Pluto. Saturn has a total of 15 rings around it, making it one of the more visually appealing planets.

URANUS

About the Planet: Uranus Uranus is the seventh planet from the sun. It was discovered on March 13, 1781. Uranus is the third largest planet in the solar system by diameter. Uranus is named after the Greek god Ouranos, god of the sky. It takes Uranus approximately 30,707 days to complete its orbit around the sun. Uranus has an average surface temperature of 68 Kelvins. The equatorial diameter of Uranus is 51,118 km. Uranus has a total of 27 known satellites or moons, with one of its most unique being Miranda, with many grooves. Uranus has a total of eleven rings, which are nearly impossible to see from Earth, but can be viewed at certain times, when the rings are blocking stars behind them. Uranus currently has no known signs of life.

NEPTUNE

About the Planet: Neptune Neptune is the eighth planet from the sun. It was discovered on September 23, 1846. Neptune got its name from the Roman god of the sea. Neptune sometimes becomes the ninth planet from the sun due to Pluto’s orbit. It takes Neptune approximately 60,223 days to complete its orbit around the sun. Neptune has an average surface temperature of 53 Kelvins. The equatorial diameter of Neptune is 49,528 km. Neptune currently has 13 known satellites, or moons. Neptune has dark, faint rings, and currently is not known to hold life.

PLUTO

About the Planet: Pluto Pluto is the ninth planet from the sun. It was discovered on February 18, 1930. Ever since its discovery, there has been controversy over whether or not this miniscule planet is in fact a planet or not. Naming Pluto was difficult, but finally it was decided that Pluto be named after the Roman god Pluto, or Hades in Greek mythology. It takes Pluto 90,613 days to complete its orbit around the sun. Pluto has an average surface temperature of 44 Kelvins, and an equatorial diameter of 2,390 km. Pluto is by far the smallest planet in the solar system and has one satellite or moon, Charon. Not much is known about the far-off planet.