Mysteries of the Universe | | | | |  Automatic translation | | | | | | Astronomy - The curiosity that characterizes humanity, has enabled man to understand the major astronomical phenomena and it now gives a dramatic sense stronger what is happening before our eyes. In the solar system, the Sun has captured 99.86% of the total mass of dust and gas from the original nebula. Jupiter, the largest planet in the system, has captured 71% of the remaining mass. The other planets are shared residue gravitational this development, ie 0.038% of the total mass. Earth is the result of this interstellar dust. At the heart of a nebula of gas and dust, heat, through violent collisions will force the nuclei of matter, to capture electrons. When the temperature drops below a million degrees, electrons attach themselves around the nucleus in orbits closest. Gradually the seats are occupied, the atoms and molecules are arise to form a network, extremely strong: dust. | | The matter is organized everywhere in the universe in the same way. The interstellar dust are the building blocks of planets, they stick together to form small bolides, that collision in collision form objects, which grow to the detriment of their neighbors. Their masses and gravity increase, attracting themselves more matter. Collisions liberate large amounts of heat, the atoms disintegrate themselves and expect cooling to assemble molecules.
On Earth, much later, there will be assembly of simple molecules and complex molecules to reach this wonderful DNA molecule will now reproduce and store information, opening the way for biological evolution that we know.
« It is absolutely possible that beyond what our senses perceive, hide unsuspected worlds. »
Albert Einstein Nobel Prize in 1921. | |
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Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Saturn from all angles with the Astronoo simulator. | | | | |  | | Unusual images of astronomy.
"It's better to see once than hear a hundred times." | | | | |  | | 2013: Lemmon, Panstarrs and Ison, 3 comets of 2013, Lemmon and Panstarrs in March and at the end of the year, it is the comet Ison which illuminate our sky. | | | | |  | | February 15, 2013: Asteroid 2012 DA14, rise to 27 700 km of Earth on 15 February 2013 at 19 h 24 (UT), its speed will be 7.8 km/s. |
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Stars
A star is a aster similar to our sun, which shines through nuclear reactions that occur in the center.
With the exception of the Sun, the stars appear
to the naked eye as a bright, shimmering due to atmospheric turbulence, with no immediate apparent motion relative to other fixed objects in the sky.
All the stars are
considerably farther from Earth than the Sun.
The nearest star is a red dwarf, Proxima Centauri (Alpha Centauri C), located about 4 light years from the Solar System, nearly
250,000 times farther than the Sun. The mass of the star is 12.3% of the mass of the Sun, and its diameter is 200,000 kilometers (1/7 the diameter of the Sun).
Sirius is a
binary system composed of two stars, Sirius A and Sirius B located in the constellation Canis Major. The star Sirius A (α Canis Majoris) is the brightest star in the sky.
Betelgeuse is a red super giant, one of the largest stars known. Its radius is estimated to be about 900 times that of the Sun, if Betelgeuse were at the center of our Solar System it would extend between the orbits of Mars and Jupiter.
The power radiated by a star like the Sun is about 1026 watts. Stars form following the contraction of a nebula of gas and dust under the influence of gravity. If
the heating of the material is adequate, it will trigger the cycle of nuclear reactions in the heart of the nebula. This contraction of increasingly dense will form a star.
The energy released by these reactions is then sufficient to stop its contraction due to the radiation pressure generated.
The number of stars in the universe is huge,
it is estimated between 1022 and 1023, ie between 10,000 and 100,000 billion billion stars.
Apart from the Sun, the stars are too faint to be observable
in daylight.
The number of observable stars at night, to the naked eye in clear weather, varies between a hundred and several thousand depending on the viewing conditions. |
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