THE SOLAR SYSTEM Part One
"Youssef (Joseph) said one day to his father Ya'aqoub (Jacob): O my father! I saw in a dream eleven stars, (Kawakib) and the sun and the moon were worshiped me. "(Quran 12.4).
Some commentators have translated the word "kawakib" rating. However, in the Sacred Text, whenever the sun and moon with the stars are mentioned, they are called "Noudjoum" not kawakib. This word is used elsewhere as to designate the stars, the planets. The representation of the verse describes therefore the sun, moon and eleven planets, or the entire solar system. If, in its literal version is referred to the solar system, this verse also symbolizes the Prophet's family Ya'aqoub, which consisted of the applicant, his wife and his twelve son, which derived the twelve tribes of Israel . Youssef would thus have seen in a dream, his eleven brothers (planets), his father (the sun) and his mother (the moon) who adored him. Following this Surah and the story of Youssef vicissitudes, were quick to accept this reasoning. It seems amazing to see the Koran evoke eleven planets, while for the whole world, that figure was five at the time. The planets are: Mercury, Venus, Mars. Jupiter and Saturn.
- - Mercury is the closest planet to the sun. It has averaged at 57.9 million kilometers from the sun light and carries its orbit at a speed of 172,400 kilometers per hour, 10 times faster than the planet Pluto which is in contrast to 100 times further. Because of its speed, the Greeks had identified with Hermes, messenger of the Olympians. The astrological point of view, the ancients considered as a benevolent Mercury omen, but sometimes attributed to him evil powers.
2 - Venus or Evening Star is the brightest star in the sky after the sun and moon. Its brightness is twelve times greater than that of Sirius, the brightest star. Muslims know well that this star shining lights just before the hour of the Maghreb. Venus can get closer to 39 million kilometers from the earth and become the closest of the entire solar system planet. Its reflectivity is twelve times higher than that of Mercury (albedo). This is what explains its brilliance.
- - Mars has always intrigued men by its red-orange color due to a thin layer of iron oxide. In mythology, the ancients believed that this color was mentioned by the blood shed in the fighting that took place there "there." The existence of ice sheets and the presence of vast expanses assimilated greenish vegetation reinforced the feeling of a living planet. The discovery in 1859 of the famous "channels" by an Italian priest, named Secchi, conducted in 1877 Schiaparelli, director of the Milan Observatory, to hypothesize the realization of these channels by Martians. This was the great popularity of green men, for nearly a century. In 1965 the Martian myth collapsed, the suite of photos taken by the US probe "Mariner 4" which found no trace of the famous works. The results were confirmed later by Mariner 9 and the Soviet missiles, "Viking 1 and 2."
- - Jupiter is the largest planet in the solar system. Its volume is over a thousand times greater than that of the earth. It is located unlike planets already quoted, beyond the asteroid belt, where evolve beyond Pluto, the other giant planets. Jupiter has a reddish stain, observed in Europe, for the first time by the English astronomer Robert in 1664, and which led to the most diverse speculations. Photographs taken by "Voyager" in 1979, made it possible to demonstrate that it was a gigantic storm, fueled by ascension movements.
The Jovian system with its satellites has often been compared to the solar system, and astronomers speak of "sun missed." The planet emits more energy than it receives from the sun in a ratio of 1/2, 4. But she could not turn to the image of the sun and initiate thermonuclear fusion reactions in due to insufficient mass to reach the critical threshold. Specialists think that this threshold should be around 8 percent of the mass of the sun, while it is only 0.1 percent for Jupiter.
- - Saturn is the fifth and last of the planets known to the ancients. It's also a giant planet, 744 times larger than the earth and has many similarities with Jupiter. Its lowest 0.71 density of the solar system would allow it to float on water. Saturn is notable for the presence of rings already observed in 1610 by Galileo. The probe "Voyager 1" has helped bring more accuracy, including the fact that the rings were much more numerous than expected. Saturn has more than a dozen satellites, including Titan (4950 kilometers in diameter) one of the three largest satellites in the solar system.
Such were the planets known since ancient times. When the Qur'anic revelation, the Arabs had no claim to match the Greek knowledge, which limited the number of these planets to five. The major work of Ptolemy in this area, "Mathematical Syntax", deriving itself data of Hipparchus, had authority during the Middle Ages and the Renaissance. It was not known elsewhere and distributed in Europe through the "Almagest" composed by the Arabs in the 9th century. In the Ptolemaic system, the earth is the center of the universe, and then are successively Moon, Mercury, Venus, Sun, Mars, Jupiter, Saturn and the sphere of fixed stars. All these stars were supposed to orbit the earth.
With Copernicus, the earth loses its universality. Since reverses the positions of the sun and the earth. The center is now occupied by the sun and the world is relegated to third place in the solar system after Mercury, between Venus and Mars, which corresponds to reality. Copernicus also described the orbits of Jupiter and Saturn, and, quite outside the unchanging sphere of the fixed stars. The Copernican system is concentric. Another novelty is not the sphere of stars that is driven in a rotary motion, but the earth turning on itself.
In the 16th century, Copernicus, the number of planets is extended to six. For the first time in the West, a man could change a figure that was the symbol of the heavenly architecture. This will not be the last. A little more than two centuries after the English astronomer William Herschel, discovered in turn, the planet Uranus (first confused with a comet) he called "Georgius" in honor of the King of England George III. But in reality, Copernicus merely reiterated the ideas of Be?runi famous Muslim scholar who conceived the heliocentric theory, five centuries ago. See the article entitled "The Earth and the solar system." The seventh planet is located at an average distance of 2.8 billion kilometers from the sun. His fairly low density would be 1.7 and the equatorial diameter of 46,700 kilometers around. His observation is quite difficult due its remoteness and low illumination. The study of the motion of Uranus was the origin of the discovery of the eighth planet, Neptune. Indeed, Uranus disturbances presaged the presence of an unknown planet that caused these anomalies by its attraction. Based on the calculations of Le Verrier, it was observed September 23, 1846, by the German astronomer Galle, in the constellation of Aquarius.
Neptune is located at an average distance of 4.5 billion kilometers and has several satellites. The search for the ninth planet, Pluto has intervened in the same conditions as the identification of Neptune. The disturbances in the latter prompted astronomers to consider the existence of a body which would be responsible. After a tight competition, it is the American Clyde Tombaugh, who discovered Pluto at Lowell Observatory in Arizona, February 18, 1930. A 5 billion kilometers from the sun, it is the most distant of the planets solar system. Its period of revolution around the sun is 248 years and 154 days and its estimated diameter of 4000 kilometers away.
At the end of the twentieth century, great progress has been made in the counting of the planets in the solar system relative to the middle ages, and each time was "his" truth about the number of planets is the recap: Up the late 15th century, it was commonly believed that there were only five planets through which the astrologers of the time were trying to determine the fate of the men in the study of supposed influences of these stars.
In the sixteenth century, Copernicus and the introduction of the land to the planetary system, that number was increased to six (1530-1548).
In the eighteenth century, the discovery of Uranus increases the number; they will now be seven to rotate around the sun.
The nineteenth century saw a further revision with the detection of Neptune (1846), bringing the number of planets to eight.
The first part of the twentieth century brought a new change with the identification of Pluto (1930). To date, the number is still new. This figure he will be questioned? Before answering this question, it is interesting to examine the law of Titius on the distance of the planets from the sun, and the consequences of this rapprochement.
The mathematician and German physicist J. Titius, discovered in 1772, a distribution relationship of planetary distances from the sun, that in section 4 of the beginning, add the number 3 which is doubled at each stage before dividing the whole by 10. The following results: 0.4 - 0, 7-1-1, 6-2, 8-5, 2.0 etc., which must be multiplied by 150 million, representing the astronomical unit, or approximately, the mean radius of Earth's orbit. The figures obtained are amazing. Here are the results (distances from the sun):
Mercury: 150 000 000 x 0.4 = 60 000 000 km
Venus: 150 000 000 x 0.7 = 105 000 000 km
Earth: 150 000 000 x 1 = 150 000 000 km.
While the actual distances are:
Mercury 57.9 million km
Venus 108 million km
Earth 149,600,000 km