Sun The Sun is the closest star to Earth and is the center of our solar system. The Sun is fueled by nuclear fusion reactions. The light from the Sun heats our world and makes life possible. The Sun is nearly 5 000 000 000 years old. Maybe in nearly 6 400 000 000 years it will change into red giant. At the ebd of his life the Sun will change in white dwarf. The temperature inside the Sun is 5500 C (Celsius´ degrees). Rotation of Sun itself takes 25 days and 9 hours. Its equatorial diameter is 1 392 000 km and its capability is 1 304 000 – times larger than the capability of our Earth.

Mercury 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 planet does not have any moons. Its equatorial diameter is only 4 878 km and the weight is only the 1/17 of the weight of Earth. The distance of Mercury from the Sun is 58 000 000 km and the year is only 88 days. Temperatures on the surface are from 450 C to -183 C.

Venus Venus is the second planet from the Sun, and is Earth’s closest neighbor in the solar system. Venus is the brightest object in the sky after the Sun and the Moon, and sometimes looks like a bright star in the morning or evening sky. The planet is slightly smaller than Earth, and its interior is similar to Earth. We can’t see the surface of Venus from Earth, because it is covered with thick clouds that strongly reflect sunlight. However, space missions to Venus have shown us that its surface is covered with craters, over 1600 major volcanoes, mountains, large highland terrains, and vast lava plains. The surface of Venus is not where you’d like to be, with temperatures reaching more than 450C, an atmosphere 90 times heavier than our own, and clouds of sulfuric acid floating around to top it off. The surface temperature is 480 C. The equatorial diameter is 12 104 km, distance from the Sun is 108 000 000 km and 1 year is 224 days.

Earth Our home. It is the third planet from Sun. Earth, the largest and densest rocky planet, was formed about 4.5 billion years ago. It has its own atmosphere. The atmosphere surrounds Earth and protects us by blocking out dangerous rays from the sun. The atmosphere is a mixture of gases that becomes thinner until it gradually reaches space. It is composed of Nitrogen (78%), Oxygen (21%), and other gases (1%). The equatorial diameter is 12 756 km and the weight is 5.98×10^24 kg. Day takes 23 hours and 56 min, one year takes 365 days and 6 hours. The Earth has one moon (Moon).

Mars 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. The uniquely red global surface of Mars is marked by many interesting features – some like those on the Earth and others strangely different. The reddish color is caused by rust (iron oxide) in the soil. Some of these features are; volcanoes, canyon systems, river beds, cratered terrain, and dune fields. Diameter is 6,785 km rotation period about its axis is 24.6 hours. The mass: 0.64×10^24 kilograms. One year on Mars is 1.88 years on the Earth. Mars has two moons: Phobos and Deimos.

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Jupiter 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. The Giant planets do not have the same layered structure that the terrestrial planets do. Their evolution was quite different than that of the terrestrial planets, and they have less solid material. Jupiter’s interior composition is primarily that of simple molecules such as hydrogen and helium, which are liquids under the high pressure environments found in the interiors of the outer planets, and not solids. Jupiter has 60 moons and a ring system. The four Galilean satellites; Io, Europa, Ganymede, and Callisto, are among the most interesting of all solar system bodies, particularly Io, with its active volcanism, and Europa with the possibility of a water environment friendly to life. The Galileo spacecraft explored many other moons while orbiting Jupiter for eight years 1996-2003. Diameter of Jupiter is 142,800 km, rotation period about his own axis is 9.8 hours. The mass of Jupiter is 1,898 x10^24 kilograms. One year takes 12 years.

Saturn Saturn, the sixth planet from the Sun, has the most spectacular set of rings in the solar system. We now know that Saturn has 31 moons in addition to its complex ring system. The atmosphere of Saturn, like Jupiter, is only a narrow region, compared to the vast interior of Saturn. The three clouddecks of Saturn are to be found mostly low in the atmosphere, while hazes of smog can be found higher up. Diameter: 119,871 km. Rotation period about axis takes 10.67 hours. The mass of the planet is 586.5×10^24 kilograms. One year takes 29,5 years on the Earth. The gas giant planet Saturn has a large group of 31 moons. It also has the largest, most complex, and best-known ring system in our Solar System.

Uranus 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. Diameter of the planet is 51,488 km, rotation period about axis is 17,24 hours. The mass is 86.8×10^24 kilograms. Revolution period about the Sun is 84 years.

Neptune Neptune, which is usually the eighth planet from the Sun, is a very cold place. Occasionally, the ninth planet Pluto crosses Neptune’s orbit and becomes the “eigth planet”. Its bluish color comes from its atmosphere of methane gas. The planet has 13 moons and a very narrow, faint ring system. Neptune has 13 moons. It also has rings, but its rings are different from Saturn’s. Diameter is 49,493 km , rotation period about axis is 17.24 hours. The mass of planet is 102.4×10^24 kilograms. Revolution period about the Sun: 165 years.

Dwarf planets:

Pluto is the only planet that has not been visited by a spacecraft from Earth. This mysterious planet is really a double planet system, since its moon, Charon, is very close to Pluto and about the same size. Pluto’s unique orbit causes it to periodically come within the orbit of Neptune. Pluto was the eighth planet from the Sun from February 7th, 1979 through February 11, 1999. Now Pluto will remain the ninth planet through the 23rd century. Data from 1999 suggests that the surface of Pluto is made of two different parts. It has an icy part and a non-icy part (the non-icy part may be some sort of rock). Scientists are fairly certain the icy part is made of frozen nitrogen, but also contains smaller amounts of frozen carbon monoxide and methane. Pluto is so far away that is it very hard to see the planet, so we can’t yet tell how much of the surface is covered with ice, and how much is covered with something which is not ice (the possibly rocky part). It will take a mission to Pluto to sort some of these things out! Scientists are certain that the surface of Pluto is good at reflecting light, which suggests that it is mostly made of the icy component – and that means Pluto’s surface is mostly composed of nitrogen. The interior of Pluto is probably similar to that of major icy moons such as Ganymede. (Pluto is actually smaller than Ganymede, even though Ganymede is a moon). Pluto’s moon, Charon, is 12,200 miles from the planet and has a diameter of 1,200 km (740 miles). Charon was first seen from Earth in 1978. Pluto and Charon are similar in size, and they orbit each other like a double planet, with the same sides permanently facing each other. Diameter: 2,301 km, rotation period about axis: 6,4 days (retrograde) Mass: 013×10^24 kilograms, revolution period about the Sun is 248 years.

Sedna This object is three times farther away from Earth than Pluto, making it the most distant known in the solar system. Astronomers definitelly doesn´t know, if the Sedna is the 10th planet of Solar System, or it is only rock.