The Planets

There are a total eight planets in the solar system –

Ø The planets are divided in the two groups – Inner planets and Outer planets.

Ø Inner planets – Mercury, Venus, Earth, Mars.

Ø These are also known as terrestrial planets or rocky planets. These are denser and have a shorter periods of revolution.

Ø Outer planets – Jupiter, Saturn, Uranus, Neptune.

Ø  These are also known as Gas Giants or Gaseous planets. They are big in size and have a longer periods of revolution.

Ø Jupiter is the biggest planet in the Solar System and Mercury is the smallest.

Mercury

Ø  Mercury is the closest planet to the Sun.

Ø  Mercury  has No natural satellites (moons).

Venus

Ø Venus is known as Earth’s twin.

Ø Longest rotation period of any planet.

Ø Venus is the hottest planet in the solar system.

Ø Revolves around the sun in clockwise manner while most others are revolving in anti-clockwise.

Ø No natural satellites (moons).

Earth

Ø  Earth is the only planet in the solar system to be known to support life.

Ø  Earth has water in all three states – liquid, solid and gas.

Ø  Gasses present in the earth’s atmosphere are Nitrogen, Hydrogen, Oxygen, Carbon Dioxide etc

Ø  Earth  takes 23 hour 56 minutes 46 seconds to rotate around its axis.

Ø  Earth  takes 365.26 days to revolve around the Sun.

Ø  The Ozone layer present in the Earth’s atmosphere protects it from the ultra violet rays.

Ø  Moon is the only natural satellite of the Earth.

Mars

Ø  Mars known as the ‘Red Planet’ due to presence of iron-rich red soil.

Ø  Phobos and Deimos are the two moons of Mars.

Ø Mars has the largest known volcano (and second tallest mountain) in the solar system 

 

Jupiter

Ø Jupiter is the largest planet of the solar system.

Ø Jupiter has the shortest rotation period.

Ø Jupiter has 67 moons. 4 largest moons  Ganymede (largest moon in the solar system – bigger than Mercury), Callisto, Io (volcanic), Europa (has water-ice).

Saturn

Ø Saturn is the second largest planet in the Solar system.

Ø Saturn has a band of concentric rings revolving around it made up of tiny rocks and pieces of ice.

Ø Saturn has 62 moons. Titan is the largest

 Uranus

Ø   Uranus is the third biggest planet of the solar system.

Ø Composed of Hydrogen, Helium, Water, Ammonia, Methane.

Ø Uranus is tilted sideways so that its poles lie where most other planets have their equators.

Ø   Uranus Has 27 known moons (5 main – Miranda, Ariel, Umbriel, Titania, Oberon).

Neptune

Ø Neptune is the farthest planet from the Sun.

Ø Neptune is blue in color because of methane.

Ø Neptune has a storm called ‘Great Dark Spot’.

Ø Neptune has 14 known moons (Triton – largest)

Pluto

Ø Demoted to status of “Dwarf Planet”.