Author: Katarzyna Czernecka

Every day people observe the sky and see sunrise, long Sun's way on the sky and sunset. It makes them willing to know something more and more about the Sun and the Solar System. Our solar neighborhood is an exciting place. The Solar System is full of planets, moons, asteroids, comets, minor planets, and many other exciting objects. Nowadays, we have a lot of informations and it is obvious that the Earth together with seven planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune) and many other smaller astronomical objects move around the Sun. Not long ago, also Pluto was said to be a planet but it changed. Now it is known that Pluto is a dwarf planet.

The Sun

The Sun is the center of our solar system and is the closest star to Earth. A giant ball of very hot gas, the Sun is fueled by nuclear fusion reactions. The light from the Sun heats our world. It makes life possible. This star provides all the energy necessary to sustain life on Earth.
The surface of the Sun in cooler than its atmosphere. The Sun's surface is a warm 6,000 degrees Celsius.  This is the same temperature as the Earth's core.  However away from the Sun's surface the atmosphere heats up to millions of degrees.  Scientists are not sure how the atmosphere can be as hot as it is, with such a cool surface.

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Solar system

The Solar System is made up of all the planets that orbit our Sun. The inner planets: Mercury, Venus, Earth, and Mars. The four inner or terrestrial planets have rocky compositions, dense, few or no moons, and no ring systems. The outer planets: Neptune, Uranus, Saturn, and Jupiter. The four outer planets, or gas giants (sometimes called Jovian planets), collectively make up 99 percent of the mass known to orbit the Sun. All four gas giants have rings. In addition to planets, the Solar System also consists of moons, comets, asteroids, minor planets, and dust and gas.

Everything in the Solar System orbits or revolves around the Sun. The Sun contains nearly 100% of all the material in the Solar System. The larger an object is, the more gravity it has. Because the Sun is so large, its powerful gravity attracts all the other objects in the Solar System towards it. At the same time, these objects moving very rapidly try to fly away from the Sun, outward into the emptiness of outer space.

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The history

The creation of our Solar System took place billions of years before there were any people around to witness it. Scientists believe that the Solar System evolved from a giant cloud of dust and gas. They believe that this dust and gas began to collapse under the weight of its own gravity. As it did so, the matter in this could begin moving in a giant circle, much like the water in a drain moves around the center of the drain in a circle. At the center of this spinning cloud, a small star begin to form. This star grew larger and larger. Further away from the star that was forming in the center were smaller clumps of dust and gas that were also collapsing. The star in the center eventually ignited forming our Sun and the smaller clumps became the planets, minor planets, moons, comets, and asteroids.

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The planets

1. Mercury - the planet nearest the Sun, is the second smallest planet in the solar system. Only slightly larger than the Earth's moon, Mercury's surface is covered with craters. This tiny planet does not have any rings or moons.
2. Venus - is close in size to Earth. However, it is much drier than Earth and its atmosphere is ninety times as dense. Venus has no natural satellites. It is the hottest planet.
3. Earth - our home planet, is a beautiful blue and white ball when seen from space. The third planet from the Sun, it is the largest of the inner planets. Earth is the only planet known to support life and to have liquid water at the surface.
4. Mars - Earth's outer neighbor, is the fourth planet from the Sun. Mars' bright appearance and reddish color stand out in the night sky. Impressive surface features such as enormous volcanoes and valleys are frequently obscured by huge dust storms.
5. Jupiter - is the largest planet in the solar system. When approached from afar, its fantastic striped atmosphere gradually reveals intriguing clouds that move around the planet. Rich in historical and cultural connections, Jupiter is the site of recent comet impacts and continuing scientific discovery.
6. Saturn - the sixth planet from the Sun. famous for its extensive ring system, has similarities to Jupiter, such as its atmospheric composition. Saturn is far less massive, being only 95 Earth masses. Saturn has fifty-six moons; two, Titan and Enceladus, show signs of geological activity, though they are largely made of ice.
7. Uranus - the seventh planet from the Sun, has its spin axis almost in the plane of its orbit about the Sun. This produces unusual seasons and also causes unique magnetic and electric field structures. Uranus has a faint ring system and 27 known moons.
8. Neptune - which is usually the eighth planet from the Sun, is a very cold place. Occasionally, the dwarf planet Pluto crosses Neptune's orbit. Its bluish color comes from its atmosphere of methane gas. The planet has 13 moons and a very narrow, faint ring system.

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Images

The Structure of the Sun:

The Sun compared to other stars:

Both of the images are available as a public domain.

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