Sun and Its Family

 

 

The development and acceptance of the heliocentric system (sun-centered/solar system), where the sun is considered as the center of the eight planets, helped the astronomers predict the position of the planets and its orbits. it has been indicated that the solar system consists of an ordinary star, the Sun, and around it revolved the planets and other heavenly bodies.

Planets were divided into two groups. First, the inner planets(Terrestrial planets). this consist of Mercury, Venus, Earth and Mars. Second, the outer planets(Jovian planets). Jupiter, Saturn, Uranus and Neptune are the planets that belong to this group. 

 

 

Below are the information about each planet:

Mercury- The smallest planet among the four inner planets. It makes one revolution around the sun in 88 earth's day. It is named after the messenger of the Greek gods. It is also considered as the hottest and coldest planet because there are no wind to carry heat from one region to another during night time due to very little atmosphere.

Inner Planets

Venus- the brightest star in the evening and in the morning sky. Because of its beauty, it is named after the goddess Venus. it is also considered as the twin sister of earth. its revolution is 225 earth days long. It has very dense atmosphere and opaque cloud cover and a green house that makes its atmosphere very hot.

Earth- the only planet that is capable for living organisms because of the atmosphere that enveloped it. It is also known as the Blue planet due to the abundance of its ocean. It revolves around the sun within 365 days.

Mars- this planet was named after the god of war. Its reddish color is due to the abundance of ferric oxide on its surface.It is smaller compared to earth and venus. It has low atmospheric pressure, lacks oxygen, scarcity of water and extreme change in temperature.

Outer Planets

 

Jupiter- the biggest among the planets. It was named after the ruler of Olympian gods due to its size. It is more liquid than gaseous and solid. Its atmospheres composition consist of hydrogen, helium, methane, ammonia and other molecules.

Saturn- A unique planet because of its rings. The slowest moving planet because of its slow pace. Its rings are composed of chunks of frozen water and rocks.  Its largest satellite is Titan.

Uranus- Discovered by William Herscbel in 1781. Its axis is tilted to 98 to the perpendicular of its Jupiter and Saturn because it has no internal source of heat.

Neptune- Its atmospheric composition is mainly hydrogen and methane with some helium and ammonia. Its largest satellite is Triton. It was named after the god of the sea.