Study Notes On Facts About Solar System

Cosmology: Science dealing with the nature and origin of the universe

Big Bang Theory: Canon Lemaitre

Steady State Theory: Hermann Bond and Thomas Gold.

Pulsating universe theory: Allan Sandage.

One Parsec = 3.26 light years.

Hydra is the largest constellation.

When brightness of a star increases 20 magnitudes or more, it is called a supernova.

Sun accounts for 99.85% of the mass of the solar system.

Suns Revolutionary period= 250 m years

Rotation time = 25 days

Planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune

Venus and Uranus rotate anti- clockwise at their axis, whereas all other planets rotate clockwise.

Largest Terrestrial Planet:- Earth

Smallest Jovian Planet:- Neptune

Mercury and Venus have no satellites.

Jupiter has the largest rotational velocity.

Genemede of Jupiter :- Largest Satellite

Titan is the only satellite in the solar system with an atmosphere of its own.

Saturn has the least density among all the planets.

Uranus is also known as Green planet.

Greatest satellite of Neptune : Triton

Facts about Earth's Surface

The Crust: It has two layers: Sial and Sima. These two layers extend to a distance of 30-40 km from the earth's surface. The join of Crust and Mantle is called Mohorovic Discontinuity.

The Mantle: It extends from 35-2900 km. The join of Mantle and Core is called the Gutenberg Discontinuity.

The Core: It extends from 2900-5150. It is also called NiFe because of the presence of Nikel and Iron.

Mechanical Division of Mantle

1. Lithosphere: It constitutes 80-100 km of upper most mantle. It is rigid and cool

2. Asthenosphere: It is also a part of the upper mantle. It is hot, soft and pliable.

Remember: All the meridians and only the equator form great circles.

Composition of Earth

1. Crust Composition: Oxygen: 46.8%, Silicon: 27.7%

2. Total Earth Composition: Iron: 35%, Oxygen: 30%, Silicon: 15%

Continental Drift Theory

According to Alfred Wegner about 250m years ago, all continents were united on a super continent called asPangaea, which was surrounded by a large ocean called Panthalsa.

Continents Drifted in Two Directions:

a. Towards Equator: Due to Gravitational attraction of equatorial bulge ( caused the formation of Himalayas, Alps, and Atlas)

b. Towards West: Owing to tidal forces of moon and sun ( Caused the formation of Rockies and Andes)

Rocks, Earthquakes and Volcanism
About 90% of rock forming minerals are silicates.
Felspar is the most abundant rock forming silicate material.
About 75% of the surface area of the globe is covered by the sedimentary rocks while rest 25% area is occupied by the igneous and metamorphic rocks.
Shale is the most abundant sedimentary rock.
5. Marble is a metamorphic rock from limestone, Diamond from Carbon etc.
Richter scale is used to assess the magnitude of an earthquake. It is logarithmic, it means each whole no on the scale represents a tenfold increase in the measured wave amplitude. It is a quantitative scale.

Intensity of earthquake is measured by Mercalli Scale. It is a qualitative scale.

Earth's Movements

Faults: Here the rock beds are dislocated and displaced resulting in the formation of faults.

Rift Valley: Is a linear depression on earth eg. Narmada and Tapti. Dead Sea, the most saline lake after Lake Van are situated in a rift valley.

66% of the earthquakes of the world are recorded in Circum-Pacific Zone.

With the increasing depth, the temperature rises gradually at 1 deg C per 32 m.

Molten rock material below Earth's surface is called Magma, above Earth's surface is called Lava.