• THE SOLAR SYSTEM:

The Solar system is a tiny part of a galaxy & consists of the sun and all the objects that travel around it. It includes the Earth and eight other planets, along the satellites that travel around most of them. It further includes Asteroids, Meteoroids, Comets, Interplanetary dust & interplanetary plasma. The planets are described in detail below: -


1. Mercury:

It is the rocky planet.

It is covered with holes called Craters.

It has no moon.

It has no atmosphere.

It is the nearest planet to the sun.

It is also the smallest planet of the solar system.

It is the fastest planet.

The temperature on mercury vary between 420 0C (7900F) in the day and -180 0C (-2900F) at nights.

Its distance from Sun is 58 million kms.

Its revolution period is 88 days.

Its rotation period is 58 days, 15 hours and 30 minutes.

Its radius is 2,433 kms and diameter is 4,878 kms.



2. Venus:
Apart from the moon, Venus is the brightest object in the sky. Venus can be seen with naked eye in the Morning or in the evening. Following are the main characteristics of the Venus.

It is the rocky planet.

It is also called morning star.

It is the brightest planet.

It has no moon.

It is the slowest rotating planet.

It is also the hottest planet.

It is the nearest neighbor of the earth in the solar system.

It has longest daytime. (225 Earth days).

It rotates from east to west as opposite to most other planets.

Its distance from the Sun is 108 million kms.

Its revolution period is 224.7/225 days.

Its rotation period is 243 days and 14 hours (longest day).

Its diameter is 12,102 kms.

It is wrapped in thick clouds of CO2 gas.


3. The Earth:
The earth is the largest and the densest of the four terrestrial planets. It is the most wonderful planet of the solar system. Following are the features of the Earth.

It is the rocky planet.

It is the densest planet.

It is also the watery and bios planet.

It has one moon.

Its two-thirds surface is covered with oceans.

The earth’s surface is rich in Oxygen, Silicon, Aluminum, Iron, Calcium, Sodium etc.

It has atmosphere which contains 78% Nitrogen, and 21% Oxygen.

Its distance from the Sun is 150 million kms.

Its revolution period is 365 ¼ days.

Its rotation period is 23 hours, 56 minutes, 40 seconds.

Its diameter is 12756 km (7927 miles equatorial and 7900 miles polar diameter)


4. Mars:
Mars is the 4th planet of the solar system which is visible by a naked eye as abright red spot in the sky.

It is the rocky planet.

Mars is covered with red dust & is red planet.

It has two moons Phobos and Deimos.

Its average temperature is -53 0C.

Distance from the sun 228 million kms.

Revolution period 687 days.

Rotation period 24 h, 37 min and 22 sec.

Its diameter is 6794 kms.

It has an atmosphere composed almost entirely of CO2.


5. Jupiter:
It is the largest & heaviest planet of the solar system.

It is the fastest rotating planet.

It has 63 moons.

It has the largest number of satellites.

It has the shortest daytime. (10 hr).

It has a dense, cloudy atmosphere of hydrogen and helium.

Its distance from sun is 778 million kms.

Revolution period 12 years.

Rotation period 9h, 50min, and 30 sec. (smallest day)

Its diameter is 1, 24,800 kms.

Its diameter is eleven times greater than the earth’s diameter.

It has a rock-iron-ice core about 15, 000 km (9,000 miles) thick.

Jupiter radiates 67% more heat than it receives from the sun. This is mainly due to dissipation of the primordial heat of the planet.

It has 16 satellites.


6. Saturn:
In 1610, Galileo became the first person to look at Saturn through telescope.

It is the second largest planet.

It has brightest rings.

It has a magnificent system of rings.

It has 62 moons.

Distance from Sun 1427 million kms.

Revolution period 30 years.

Rotation period 10h, 14 mins.

The largest moon of Saturn is the Titan and it is the second-largest moon in the solar system. Titan is larger than the planet Mercury.

Its diameter is 1, 20, 000 km.

According to Guiness book of answers, Saturn has 18 known satellites.


7. Uranus:
When sky is very dark and very clear Uranus can be seen with the naked eyes. William Herschel discovered the planet in March 1787.

It is greenish planet.

It has 27 moons.

It has an atmosphere, which is dominated by hydrogen and helium.

Its distance from Sun is 2869.9 million kms.

Revolution period is 84 years.

Rotation period is 16h, and 10 mins.

Titania is the largest moon of Uranus.

Its diameter is 52, 400 km.

It has 15 known satellites.


8. Neptune:
The German astronomer Johann Galle discovered Neptune.

It is the coldest & blue planet.

It is the slowest to move around the sun.

It is known as the twin of Uranus due to their similarity of size, mass and composition.

Neptune has 13 moons that we know of. The largest moon is Triton.

Distance from Sun 4496, 6 million kms.

Revolution period 165 years (largest year)

Rotation period 18 hours.

Its diameter is 49,100 kms.


9. Pluto:
It is not considered as Planet now, but is classified as dwarf planet.