SPACE Prapti Dutta

The solar system The solar system includes the Sun and all the objects that orbit around it due to its gravity. This includes things such as planets,  comets ,asteroids, meteoroids and moons. The Solar System formed around 4.6 billion years ago. There are eight planets in the Solar System. The four inner planets are Mercury, Venus, Earth and Mars while the four outer planets are Jupitar, Uranus and Neptune. The inner planets (also known as terrestrial planets) are smaller and made mostly of rock and metal. The outer planets (also known as gas giants) are much larger and made mostly of hydrogen, helium and other gases. As of 2008, there are also five dwarf planets:Pluto, Ceres, Eris, Makemake & Haumea. There is an asteroid belt which lies between the orbits or Mars and Jupiter, it features a large number of irregular shaped asteroids. For thousands of years humans were unaware of the Solar System and believed that Earth was at the center of the Universe. Astronomers such as Nicolaus Copernicus, Galileo Galilei, Johannes Kepler and Isaac Newton  helped develop a new model that explained the movement of the planets with the Sun at the center of the Solar System. The Sun contains 99.86 percent of the Solar System's known mass, with Jupiter and Saturn making up making up most of the rest. The small inner planets which include Mercury, Venus, Earth and Mars make up a very small percentage of the Solar System’s mass.

The stars There are approximately 400 billon stars in the galaxy. With as many as 500 billion galaxies in the Universe, it is almost impossible to count how many stars are there in the Universe. Stars are made out of dust clouds scattered throughout the space. The turbulence within these dust clouds gives rise to knots which later on develop mass, allowing gas and dust to collapse. While this cloud collapses, the object that is present at the center starts to heat up. This hot core becomes a star later on. The stars do not twinkle. In fact it is the turbulence in the sky that makes the stars appear that they are blinking. The closest star to Earth is Proxima Centauri. It is located about 4.2 light-years away from the Earth. There are many different colors of stars. There are red, white, as well as blue stars. Hot stars give away blue lights and cool stars look white. The sun is the smallest star. It is referred as a G2 yellow dwarf star. Most other stars are red dwarfs. Betelgeuse is about 20 times the mass of the Sun and it’s 1,000 times larger than the Sun. The largest known star is the monster VY Canis Majors. This star is believed to be 1,800 times the size of the Sun!! It seems that most stars are out there by themselves, but they are actually in pairs. These are the binary stars. Some stars appear in 3, 4 and more numbers, creating a beautiful system in the sky. The bigger the star, the shorter is its life. This is true because larger stars consume their energy at a much faster rate than the smaller ones. Eta Carinae which is thought to be the most massive star has been around for a few million years only. And Sun which is the smallest of all the stars has been burning bright for billions of years and will continue to do so for many more years. When you look at stars you are literally look back in time. This is because the light from the star takes millions of years to reach the Earth. When you look at any star, you are actually looking how it looked thousands of years ago. .

EXTRA FACTS Extra facts Saturn's moon Titan has plenty of evidence of organic (life) chemicals in its atmosphere. 2. Life is known to exist only on Earth, but in 1986 NASA found what they thought might be fossils of microscopic living things in a rock from Mars. 3. Most scientists say life's basic chemicals formed on the Earth. The astronomer Fred Hoyle said they came from space. 4. Oxygen is circulated around the helmet in space suits in order to prevent the visor from misting. 5. The middle layers of space suits are blown up like a balloon to press against the astronaut's body. Without this pressure, the astronaut's body would boil! 6. The gloves included in the space suit have silicon rubber fingertips which allow the astronaut some sense of touch. 7. The full cost of a spacesuit is about $11 million although 70% of this is for the backpack and the control module. 8. Ever wondered how the pull of gravity is calculated between heavenly bodies? It's simple. Just multiply their masses together, and then divide the total by the square of the distance between them. 9. Glowing nebulae are named so because they give off a dim, red light, as the hydrogen gas in them is heated by radiation from the nearby stars. 10. The Drake Equation was proposed by astronomer Frank Drake to work out how many civilizations there could be in our galaxy - and the figure is in millions. 11. SETI is the Search for Extra Terrestrial Intelligence - the program that analyses radio signals from space for signs of intelligent life. 12. The Milky Way galaxy we live in: is one among the BILLIONS in space.