The sun is the biggest object in our solar system. Its gravity holds the plants in their orbits around it.
Scientists tell us that there is a lot of activity on the sun. They are always trying to understand the sun’s activities and how they affect us.
*Fusion
- The sun is made up of mostly hydrogen gas. The atoms of hydrogen in the sun join up to form another gas, called helium. This reaction, or joining up of atoms, releases a huge amount of energy. Some of this energy reaches us in the form of eat and light.
* Solar wind
- Sometimes continuous streams of particles are given off by the sun and blow into space. It takes 4-5 days to reach the earth. These particles affect the whole solar system-the tails of comets get turned away from the sun, spacecraft get pushed around and electronic communications on earth get disrupted.
*Sunspots
- Small dark patches which are cooler than their surroundings appear on the earth sun’s surface. These spots have different shapes and sizes, but are larger than the earth. They last for some time and then disappear.
*Prominences
- Sometimes huge loops of burning gas erupt from the surface of the sun into space. They can last for many months, held in place by the sun’s gravity.
*Planets
- a) Mercury is the planet closest to the sun. It takes about 87 earth days to complete one revolution. It has craters on its surface just like our moon.
- b) The earth is the third planet from his sun. It is the only planet known to have water in liquid form.
- c) Neptune takes about 165 earth years to orbit the sun. Because of its tilted orbit, it is sometimes the outermost planet in our solar system.
- d) Saturn is famous for its rings –though it is not the only planet that has rings. The rings are made up of dust, rocks and icy boulders. It takes about 29.5 earth years to complete its orbit.
- e) Jupiter I the biggest planet in our system. It makes about 11 earth years to go round the sun. There is a storm raging on its surface which looks like a red spot to us on earth.
- d) Mars is called the `red planet’ because its surface looks like a red desert. It has polar caps and orbits the sun approximately every 686 earth days.
- f) Venus is the brightest object in the sky-apart of the sun. It makes about 224 earth days to complete on orbit. It has a thick atmosphere which keeps it very hot.
- g) Pluto is the planet with the titled orbit. It takes about 247 day earth years to go around the sun. It is small and rocky and has just one moon.
- h) Uranus is also known as Herschel, after the scientist William Herschel who discovered it. It has giant storms on its surface. Its orbit is equal to about 84 earth years.