CELESTIAL BODIES• Stars ,plants ,the moon and other bodies in the sky are called celestial

bodies.

• The different shapes of the disc of the moon observed during a month are called the phases of the moon.

• Nearly fifteen days after the new moon can be seen approximately once a month.

• The new moon is seen when the moon is in between the sun and the earth.

• The full moon can be seen when the sun and the moon are on either side of the earth.

• The surface of the moon is dusty and full of crater.

• A light year is used to measure very large distance. It equals the distance travelled by light in one year. Sunlight takes about 8light minutes to reach the earth.

STARS• A STAR is a large sphere of glowing gases.

• Stars change over time.

• The object switches to become a “true star” and it is then able to make its own heat and light.

• The life of the star then depends on its mass.

• The color of a star measures its temperature.

– Red=the coolest,

– Yellow=an intermediate

temperature,

– Blue=the hottest temperature

SOLAR SYSTEMThe Solar System consists of• There are 8 planet in the solar system that revolve around the sun.

• The sun is a major source of heat and light for all the planets in the solar system.

• The sun in its centre

• Eight planets,circling around the sun,moons,asteroidand

• Comets

• Scientists are quite sure, that in the beginning of our Solar System there was a huge disc of dirt, rocks, gas, ice etc.

THESUN• The sun is the star that our solar system revolves around

• The earth could fit into the sun 1.3 million times

• The sun is the largest object in the solar system

• It is mostly made up of hydrogen

• A middle-aged, average star: Mostly Hydrogen & Helium 99.8% of the Solar System ~4.6 billion years old

• Shines because it is hot: Surface Temp ~6000 C Mostly Visible, UV & IR light

• Kept hot by nuclear fusion in its core: Builds Helium from Hydrogen fusion. Will shine for ~12 billion years

MERCURY• Mercury is closest to the sun and also the fastest and the smallest

of all the planets.

• It is always present on the same side of the sun.

• Mercury is the inner planet.

• It takes about 88 days to complete one revolution around the sun.

• It is very near to the Earth, we can see it just before sunrise and just after the sunset.

• It is yellowish orange in colour.

• Mercury has no moon or satellite of its own.

VENUS• Venus is the closest planet of the sun. It is the brightest

objects seen in the night sky.

• It is also called as shining planet. It is silver blue in colour and is hot planet.

• It appears as morning star in eastern horizon and as a evening star in western horizon. But we can never see ii late in the night.

• There is no evidence of life on Venus.

• It completes it revolution around the sun in 225 days.

EARTH• The third planet from the sun

• The only planet that supports life in our Solar System

• Earth has 1 moon

• 71% of the Earth’s crust is covered with water

• it is a medium sized planet, a bit larger than Venus

• (probably) the only planet with liquid water in our Solar System

• (probably) the only planet with intelligent life in our Solar System

MARS• Fourth from the sun

• Last of the Terrestrial (Earth-like) planets

• Called the Red planet because of its color

• Mars has 2 moons.

• It is a small sized planet, half as large as Earth

• Mars is well visible to the naked eye

• Mars has been visited by robotic vehicles:Pathfinder, Spirit and Opportunity

JUPITER• Jupiter is the 5th planet from the sun and is the largest planet in

the Solar System

• Jupiter is the first of the Gas planets

• Jupiter has 61 known moons!!!

• It is the largest planet of the Solar System,more than 1.300 Earths could fit inside

SATURN• Saturn is the 6th planet from the sun.

• Saturn is best known for its rings.

• The rings around Saturn are made up of frozen gases, water ice and rock. So the rings are not solid bands around the planet.

• There are 31 moons orbiting Saturn.

URANUS• It is medium sized planet of the Solar System

• It is quite far away but still can be spotted with small telescopes

• Like Saturn, Uranus has a system of rings

• Saturn has at least 27 moons

NEPTUNE• It is medium sized planet of the Solar System, only a little bit smaller

than Uranus

• It is quite far away but still can be spotted with small telescopes

• Neptune has four rings and at least 13 moons

MOON• Moons are like little planets that encircle the real planets.

• Usually, they are much smaller than planets.

• Planets can have no moons (like Mercury and Venus), one moon (like Earth) or up to a very large number of moons (e.g. 63 for Jupiter).

• Phobos and Deimos are Mars‘ companions. Phobos means “fear“, Deimos means “panic“. Mars itself has been named for the Roman God of War.

• They are quite small (<15km) and look rather like potatoes than like moons.

ASTEROIDS• There is a large gap in between the orbits of Mars and

Jupiter. This gap is occupied by a large number of small object that revolve around the sun. These are cal led asteroids .

• Asteroids are sometimes called minor planets because the are made up Of rocks and metal. The rocks come in many s izes . Larger rocks are Asteroids.

• They are found in large areas between the orbits of Mars And Jupiter.

• Asteroid can only be seen through large telescope.

COMETS• Comets are also members of our

solar system.

• Icy nucleus, which evaporates and gets blown into space by solar wind pressure.

• Mostly objects in highly elliptical orbits, occasionally coming close to the sun.

METEOR• At night when the sky is clear and the moon is not there, you may

sometimes see bright streaks of light in the sky. These are commonly known as shooting star, although they are not stars. They are called meteors.

• A meteor is usually a small object that occasionally enters the earth’s atmosphere. At that time it has a very high speed.

• The friction due to the atmosphere heats it up. It glows and evaporates quickly.

METEOROIDS• Small (mm – mm sized) dust

grains throughout the solar system

• If they collide with Earth, they evaporate in the atmosphere.

• Visible as streaks of light: meteors

CONSTELLATIONS• The stars forming a group that has a recognisable shape is called

constellation.

• One of the most famous constellation which you can see during summer time in the early part of the night is ursa major .

• Most constellations appear in many different positions in the sky as the Earth revolves around the sun.

• Earth rotates on its axis, this makes most constellations appear to rise in the east and set in the west during the night.

URSA MAJOR• Ursa Major is probably the most famous constellation, with the

exception of Orion. Also known as the Great Bear, it has a companion called Ursa Minor, or Little Bear. Everyone living in the Northern Hemisphere has probably spotted the easily recognized portion of this huge constellation. The body and tail of the bear make up what is known as the Big Dipper.

CONSTELLATION SCORPIUS

SWAN CONSTELLATION

INDIAN SATELLITES• Indian space research organisms (ISRO)is incharge of indian

satellites. The first satellite made in India, Arybhatta was launched in 1975 by a soviet rocket.