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  Our Universe Harith, Ishaan,Kruthika, Nithin, Snehin, Swetcha, Chinmay
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  Astronomy ● On aclear night, you can see thousands of stars in the sky. you can also see some planets, like Venus, Mars, Jupiter and Saturn. ● These are known as Heavenly or Celestial objects. ● They form a part of the vast universe we live in and are usually very far from us. ● The scientific study of celestial objects developed greatly after the invention of the Telescope in the 17th century. Ishaan
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  ● The firstrecord of a telescope comes from the Netherlands in 1608. It is in a patent filed by Middelburg spectacle-maker Hans Lippershey with the States General of the Netherlands on 2 October 1608 for his instrument "for seeing things far away as if they were nearby". ● Astronomy is the study of everything in the universe beyond Earth's atmosphere. ● Scientists who pursue astronomy are called astronomers. Astronomy Ishaan
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  ● A clusterof stars is called a galaxy. ● A galaxy is a system of stars, stellar remnants, interstellar gas, dust, and dark matter bound together by gravity ● A galaxy contains billions of stars. ● Alcyoneus is the largest known galaxy of all. ● Segue 2 is the smallest galaxy known. Galaxies
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  ● Galaxies mayhave different shapes, such as elliptical and spiral. ● Some galaxies do not have a regular shape and are called irregular galaxies. ● Spiral galaxies consist of a flat, rotating disk containing stars, gas and dust, and a central concentration of stars known as the bulge. Types Of Galaxies
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  ● Elliptical galaxieshave shapes that range from completely round to oval. They are less common than spiral galaxies. Unlike spirals, elliptical galaxies usually contain little gas and dust and show very little organization or structure. ● Irregular galaxies are the most unusual of galaxies. They don't seem to fit into either the spiral or elliptical galaxy categories. They don't have nice spiral arms, but they do have dark patches of gas and dust. Types Of Galaxies
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  Types Of Galaxies SpiralGalaxy Irregular Galaxy Elliptical Galaxy
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  ● Look atthe sky from north to south on a clear, moonless night. You can see a long, faint strip of light across the sky. This is the Milky Way, also known as the Akashganga in India. ● Our planet Earth belongs to this spiral Galaxy. It consists of 100-400 billion stars. ● All the stars we see in the night sky are in our own Milky Way Galaxy . Milky Way
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  ● Our galaxyis called the Milky Way because it appears as a milky band of light in the sky when you see it in a really dark area. Why is it called the Milky Way? What is inside the Milky Way? ● The Milky Way is a huge collection of stars, dust and gas. It's called a spiral galaxy because if you could view it from the top or bottom, it would look like a spinning pinwheel. The Sun is located on one of the spiral arms, about 25,000 light-years away from the center of the galaxy. Where is the earth located in the Milky Way? ● Earth is located in one of the spiral arms of the Milky Way (called the Orion Arm) which lies about two-thirds of the way out from the center of the Galaxy.
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  ● In 1610,GalileoGalilei used a telescope to study the Milky Way and discovered that it is composed by a huge number of faint stars. ● Galileo also concluded that the appearance of the Milky Way was due to refraction of the Earth's atmosphere. ● The ancient Romans called it the Via Galactica, or "road made of milk". This is how our galaxy became known as the Milky Way. Who Discovered the Milky Way?
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  ● As billionsof stars form a galaxy, billions of galaxies together form a Universe. Thus, the universe consists of everything that exists. ● It even includes time itself and, of course it includes you. ● Universe is a name given to all the matter around us Our universe is also called the cosmos. It is originally a Greek word. ● Objects in the universe are in continuous motion. Galaxies are also in motion. The Sun, which is in the Milky Way, moves at a speed of about 220km/s. Universe
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  ● One lightyear is the distance travelled by light in 1 year, and is equal to about 9,460,000,000,000 km (9.46x10^12 km) ● The term light-year is often used in astrophysics to measure the distance between two astronomical objects. ● One light-year equals 5,878,625,370,000 miles (9.5 trillion km). Light Year
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  Astronomical Unit (AU)