The Sun , Solar Energy and Planets

1. The sun is very important in the plants' growth. The sun helps the plants to make their own food by the photosynthesis process.
2. The sun is very necessary for the other living organisms, that is, it provides us with light for the vision and to do our work.
3. The sun provides us with the heat to warm our bodies.
4. The sun provides some animals and humans (that feed on plants) with food as it helps the plants to make its own food by the photosynthesis process.
5. The sun is used in heating water and warming houses by the solar heater, which changes the solar energy of the sun into the heat energy. The heat energy is used in warming houses and heating water.

Solar energy is the energy produced by the sun

Solar panels for electricity generation

Uses of Solar Energy

1. In drying clothes, grains, fruits and meat.
2. Growing plants: - when plants grow, they use energy from the sun to manufacture their food through the process known as photosynthesis
3. Solar energy captured in solar panels and stored in batteries provides electricity used in generating industrial and home appliances like television, refrigerator, Oven, electric iron and cooker.
4. Many everyday items such as calculators and other low power consuming devices can be powered by solar energy effectively
5. Is used as a source of vitamin D for human being
6. It is used for evaporation of water from water bodies which is necessary for rain formation

Coal energy: is the solar energy stored in the bodies of plants grew thousands of years ago which after being barred under the earth for a very long time turned into coal similarly gas and oil formed from died bodies of organic matters which lived thousands of years ago.

How the use of solar energy promotes environmental conservation

1. Solar energy is used by plant during manufacturing its food through the photosynthesis. In this process, plants take up carbon dioxide from the atmosphere and releasing oxygen.
2. Moreover, Solar energy is clean and safe type of energy suitable for heating and lighting this is because it does not release soot.
3. The use of solar energy in household's helps to promote and conceive environment in the sense that it would reduce the need for firewood and charcoal, where by both once extracted pollute and destroy forest.
4. The use of solar energy also reduces the use of fuel like kerosene as a result it helps to reduce environmental pollution caused by smoke from burning fuel.
5. Formation of coal and oil: Coal is solar energy stored in the bodies of plants that grew thousands of years ago, and which after being buried under the Earth for a very long period, turned into coal.
6. Formation of rainfall: Evaporation of water, which is necessary for cloud and finally rainfall formation, also uses solar energy.

Contribution solar energy contribute to the emancipation of women

1. Helps to reduce the time would be consumed used by the women searching firewood from forest.
2. The use of solar energy equipment on cooking makes them to have more time to be involved in money making activities such as business or farming.
3. Through the use of solar energy equipment in cooking and other domestic's tasks, young girls get time to go to school and private study as it was to the boys.

The planets are bodies that revolve around the sun. Planets revolve around the sun in anticlockwise direction following paths called orbits. As they revolve around the sun, they appear to move among the stars. This is the reason why the Greeks called them the planets, which in their language means, "wandering stars".

All the light and the heat of the planets come from the sun. Hence, the temperatures on the planets depend on their relative distances from the sun. All planets revolve around the sun in the same direction in orbits that are elliptical and nearly in the same plane.

They include:

1. Mercury Mercury revolves at a distance of about 58 million kilometres from the sun. It is the closest planet to the sun and the smallest planet in our solar system. Its average surface temperature is 430°C. It is called a boiling planet because of its closeness to the sun which is extremely hot. This planet has no natural satellite.
2. Venus Venus revolves at a distance of about 108 million kilometres from the sun. Its size is close to that of the planet Earth. It is the second planet from the sun. This planet has no natural satellites. It is the hottest planet, with an average surface temperature of 462°C, most likely because of the high amount of greenhouse gases in its atmosphere.
3. Earth The planet Earth revolves at a distance of about 150 million kilometres from the sun. It has an average surface temperature of 15°C. It is the only planet in the universe known to have geological and biological activities. Therefore, the earth is the only planet which supports life. The earth has one natural satellite known as the moon.
4. Mars Mars revolves at a distance of about 228 million kilometres from the sun. It is smaller than the earth and venus. Its atmosphere is mainly composed of carbon dioxide and it has two natural satellites.
5. Jupiter This planet revolves at a distance of about 778.5 million kilometres from the sun. Its atmosphere is composed of hydrogen and helium gases. It is the largest planet in the solar system. It has 79 natural satellites.
6. Saturn This planet revolves at a distance of about 1,434 million kilometres from the sun. It is distinguished by its extensive ring system and has 62 natural satellites. The ring system is composed of solid materials such as dust. The ring system is a distinctive feature of the planet.
7. Uranus Uranus revolves at a distance of about 2,871 million kilometres from the sun. Its atmosphere is mainly composed of hydrogen, helium, and methane. It has 27 natural satellites.
8. Neptune This planet revolves at a distance of about 4,495 million kilometres from the sun. It is composed of hydrogen and helium. It also contains small amount of water and methane. It has 14 natural satellites.

Wandering stars. All planets revolve around the sun in the same orbit that are elliptical and nearly the same plane.

Pluto is not a planet because an object to be a planet, it needs to meet these requirements (criteria) defined by the International Astronomical Union (IAU) as follows:

1. It needs to be in orbit around the sun
2. It needs to have enough to pull itself in a spherical shape
3. It needs to have "Cleared neighborhood of its orbit"

Note: Any object that doesn't meet these 3 criteria is considered a dwarf planet. And so, Pluto is a dwarf planet is not a planet.

Sometimes at night, one sees objects with leading heads and right tail at the sky. These are called comets. At present, many scientists believe that comets are composed of ice crystals and fragment matters. Comets revolve around the sun far beyond the limits of Pluto. They can be seen from the earth only when they come close to the sun.

A comet

Asteroids are solid heavenly bodies revolving around the sun mostly between the orbits of Mars and Jupiter There are thousands of these, the largest having diameter of less than 800km. These bodies cannot be seen without a telescope because they are very far away.

Asteroids

Meteors are process of hard matter falling from outer space become visible between 110 and 145 km above the earth's surface, where as a result of friction with the atmosphere become hot and usually disintegrate. When they do completely disintegrate as they pass through the atmosphere reach the earth's surface and are known as meteorites.

The meteorite in Mbozi, Songwe Tanzania

Satellites are moons of the planets. The number of satellites depends on the nature and size of planet up to the moment space researches has proved that only seven planets have satellites.