4. 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.
Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. It has
the longest rotation period (243 days) of any planet in the Solar System and rotates
in the opposite direction to most other planets (meaning the Sun rises in the
west and sets in the east).
5. Earth is the third planet from the Sun and the only astronomical object known
to harbor life. According to radiometric dating and other sources of evidence,
Earth formed over 4.5 billion years ago. Earth's gravity interacts with other objects
in space, especially the Sun and the Moon, Earth's only natural satellie.
Mars (Greek: Ares) is the god of War. The planet probably got this name due to its
red color; Mars is sometimes referred to as the Red Planet. (An interesting side
note: the Roman god Mars was a god of agriculture before becoming associated with
the Greek Ares; those in favor of colonizing and terraforming Mars may prefer this
symbolism.) The name of the month March derives from Mars.
6. Jupiter is the largest planet in the solar system. It is approximately 143,000
kilometers (about 89,000 miles) wide at its equator. Jupiter is so large that all of
the other planets in the solar system could fit inside it. More than 1,300 Earths
would fit inside Jupiter.
Saturn is the sixth planet from the Sun and the second largest planet in our solar
system.
Adorned with thousands of beautiful ringlets, Saturn is unique among the planets. It
is not the only planet to have rings—made of chunks of ice and rock—but none are as
spectacular or as complicated as Saturn's.
7. Uranus:The first planet found with the aid of a telescope, Uranus was
discovered in 1781 by astronomer William Herschel, although he originally thought it
was either a comet or a star. It was two years later that the object was universally
accepted as a new planet, in part because of observations by astronomer Johann
Elert Bode. Herschel tried unsuccessfully to name his discovery Georgium Sidus after
King George III.
Saturn is the sixth planet from the Sun and the second largest planet in our
solar system. Adorned with thousands of beautiful ringlets, Saturn is unique
among the planets. It is not the only planet to have rings—made of chunks of
ice and rock—but none are as spectacular or as complicated as Saturn's.
