Snow and Snow Flakes
Snow is the frozen ice crystals of rain. When clouds are full they pour out rain but in cold weather ice crystals fall out as soft little flakes that are called snowflakes. The word snow comes from an older version of English from a long time ago called Old English. Back then, it was called snaw.
At a certain temperature (called the freezing point, 0° Celsius, 32° Fahrenheit: Celsius and Fahrenheit are systems used to read temperature), snow melts away and becomes water. Sometimes, the snow will melt very fast and become water vapor, which is water in the air. This is called sublimation. The opposite where water vapor becomes snow is called deposition.
Snow is needed for some winter sport activities like skiing and sledding (slalom). People can also play with snow and build things out of it, such as snowmen, snowballs and snowforts.
Snowflakes are small ice crystals that fall from the sky, forming snow. Snowflakes come in different shapes and sizes. All snowflakes have six points.
The Sun
The Sun is the star and the largest object in our solar system. The planets in our solar system move around the sun in orbits. Our sun can be seen in the sky in the day time. It is a large yellow ball. The sun is basically a very large ball of non-stop explosions. These explosions give off a lot of energy. Even though the sun is very far from the earth, we still feel this energy. The Sun is so bright that it can hurt to look at it and can damage your eyesight so never stare at the sun and never use binoculars or a telescope to look at it. The Sun makes light, heat and solar wind. Solar wind moves around the earth outside our atmosphere. It is made of small particles that fly away from the sun. The sun is the main source of energy for life on Earth.
The Sun is at the middle of our solar system. Each planet travels in a more-or-less round orbit with the sun in the center. Each planet orbits at a different distance from the sun. The orbits of the planets are not circles. They are curves called ellipses. The planets closest to the Sun get more heat. Planets further away are colder.
Scientists think that the Sun was born from a very large cloud of dust and small bits of ice 4.6 billion years ago. At the center of that huge cloud, some of the material started to build up into a ball. Once this ball got big enough, reactions inside it caused that ball to shine.
At that point, the Sun blew away all the rest of the cloud from itself, and the planets formed from the rest of this cloud.
The Sky
The sky is what we call the appearance of a hemisphere over our heads. On a clear day it appears blue. The deepness of the blue increases as we move from the horizon to the point above our head.
The sky is blue because of Raleigh scattering. Raleigh scattering defines the amount of scattering of light rays. Since all colors of the rainbow create a white light we should see a white sky, but blue light scatters much more than red. That is why the sky appears blue (on a cloudless day).
On a cloudy day, it appears to be grey.
For More Information:
Sun
Snow
Sky
Source: Wikipedia (All text is available under the terms of the Creative Commons Attribution-ShareAlike License)
|