Human was amazed since old ages by the sun and its huge continuous non-stop energy; thus it gives energy and warmth and keeps life on earth. It was normal than old human make the sun as a God to be worshipped and respected for its great feature in universe without being able to change its characters ; thus they established huge temples for worshiping the sun such as the Sun Temple in B’albak Lebanese city, and the Pharaoh’s made a sculpture of Sphinx as symbol for the God of Sun (Ra’). they also connected their names with the God of Sun, such as Khafra’, Manqara’ and Mankawera’; which are the name of Pharaohs’ kings given for the known pyramids in Jeeza. Human did not know that the Sun gives us energy and warmth; rather than being only a star just like other stars all around the celestial dome. The sun is not distinguished of those stars but in being close to us; as it is only 149.6 million kilometers far from the earth, and light needs 8 minutes and third second to pass the distance between the sun and earth, the light needs 4 years and 3 months for passing distance between the sun and the closest star (Centaurus)! Sun being close to us compared to the stars in galaxy benefits us in studying its composition, recognizing its main components and how to produce energy along with magnetic activity and other things. Studying the sun provides us with adequate information about the stars in the galaxy as it is a perfect sample of stars and available for studying whenever we want! General Features of the Sun Sun is 149 million, 597 thousand and 893 kilometers far from the earth, which is called the Astronomical Unit, it is far from our galaxy “Milky Way” center by 28 thousand light year, and it moves around the center of galaxy by 220 km/second of velocity and completes each round around the center every 225 million years, which is called (cosmic round) or (cosmic year). The sun year did not complete its round around the center of galaxy since the age of dinosaur that lived on earth before around 65 million years! While sun density reaches 1.49 of water density, thus it is very close to that of Jupiter. The mass of sun reaches 1.989 million billion billion tons, or we may say that it equals 332.946 times of earth mass, or 700 times of all planets. The diameter of the sun reaches one million 392 thousand kilometers; i.e. the size of the sun is bigger that that of the earth by around one million, 303 thousand and 600 times. The average temperature of the surface is 5500 degrees, while in the nucleus it reaches 15 million degrees, and it moves around its axis every 25.4 earth day on average.
The Moon is the closest celestial body to the earth and it is the sole celestial body moving around it and the closest one to the sun in the solar system; as Mercury and Venus has no moons moving around it. The moon may be considered with the earth as two bodies since the earth moon is huge compared to the others. The moon attracted human attention since old ages; as it lights the earth at night when it is full and this helped human in hunting in addition to being used as a cosmic clock for recognizing time and religious events. Religions, especially Islam, still consider the moon as the main tools for determining the beginning of months especially Ramadan, Shawal and Thu Al-Hijja for Hajj and Arafah, along with other worships that may not be determined without the moon. General Features The moon diameter reaches 3476 kilometers and it is 384 thousand and 400 kilometers far from earth. The moon moves around its axis within 27 days, 7 hours and 43 minutes and 11.87 seconds and moves around the earth within the same period; i.e. the moon has the same moving period of moving around the earth, which is the prominent feature between the other planets, thus it is not only the earth moon that has equal day and year, and that’s why only one half of the moon appears to be directed towards the earth since creation and we never saw the other half unless in the space when the ships visited the moon and took photos for the other half. The axis of moon moving in its orbit around the earth tilts by 1.53 degrees and its orbit around the earth tilts to the horoscope circle between 4.58 to 5.9 degrees. The moon density reaches 3.342 compared to that of water while its mass reaches 0.0123 of the earth mass; while its size reaches 0.0203 compared to that of earth; while the escape velocity is 2.38 kilometer per second while its gravity reaches 0.1653 of earth. Moon phases The moon has always a bright half, which is the one facing the sun, and another dark half away from sunrays. From earth; we can see the bright half every night and the size of the bright part depends on the moon location to earth. When the moon is on the same line between the sun and moon we don’t see the moon at all, since the bright side is towards the sun and the dark side is towards the earth, and Arabs call the moon in that case “Wane”. The end of the lunar month when the moon is in conjunction, and foreign astronomers call it the New Moon. Then the moon moves towards the east; thus, a small part of it appears from the bright half of the moon as a crescent and it is seen directly after sunset above the west horizon and continues for the first three days after conjunction or “birth”. Then the bright half increases size over the nights until passing 90 degree in moving around earth, i.e. quarter, and then it is called the First Quarter. In the first quarter, the moon appears in the center of the sky as half-moon directly after sunset and its age is 7 nights, then it completes moving around the earth towards the east every night by 13 degrees in the sky until passing 180 degrees in moving around the earth, i.e. the half. The moon appears from the east after sunset and sets upon sunrise, and in this case it is called the Full Moon, whereas the bright half appears in full since it is in both earth and sun direction, and that means that the earth is located between the sun and moon and its age is 14 nights. Then the moon continues moving around the earth in opposite phases; as it passes in the second quarter after 21 nights and returns to conjunction again to announce a new month. Lunar Eclipse When the moon is full, it is close to the earth shade cone behind it and the moon does not pass from earth shade when it is full, because of the moon orbit on the horoscope circle being of 5 degrees and 8 minutes; thus its passes above earth shade or under it and escapes it, but sometimes the moon passes through earth shade and Eclipse happens. Lunar Eclipse passes by the following phases: 1. Start of Penumbra, which is moon entering the light shade around the heavy shade of earth, and seeing that Penumbra is difficult to regular people who do not have experience in observing the moon and eclipse; whereas a slight faint in its brightness appears before entering earth shade, and the Arab scientist Al-Bayrouni called that semi-shade Al-Shawb 2. Start of Partial Eclipse, which is moon entering the actual earth shade, when eclipse starts moving earth shade to the eastern part of moon and then starts the partial eclipse for entering part of the moon in earth shade. The moon might enter in part of earth shade all along eclipse period, and in case of entering entirely in earth shade, then it is called Total Lunar Eclipse. 3. Total Lunar Eclipse, which is moon entering the earth shade entirely 4. Total eclipse end, in which phase the eastern part of the moon starts escaping earth shade and seeing sunrays again 5. Partial eclipse end, in which phase the partial eclipse of the moon ends and the moon entirely escapes earth shade 6. Penumbra End, in which phase the earth escapes the Penumbra from the eastern side of shade The moon does not entirely disappear rather than appearing in the red cooper color, which is resulting from sun light that is scattered in the earth gas sphere, whereas the gas sphere absorbs all rays of solar spectrum except the red spectrum with the longer wave, and it continues its way from earth sides towards the moon, thus appears in red, and in case this phenomenon does not happen the moon would disappear in Eclipse. The intensity of the red color of the moon during eclipse depends on the nature of gas sphere of the earth; in case the percentage of water vapor and CO2 is high, then it would prevent a huge amount of the red rays from entering the earth gas sphere and fall on moon; thus the moon appear in total eclipse dark and black; while in case the percentage of gases is little; then a huge percentage of red rays shed on the moon and it appears in copper red color. From this concept; you may study the nature and extent of earth gas sphere pollution. A total lunar eclipse took place on 9/12/1992 AD, where the moon appeared in heavy red to black color and astronomers justified that because of heavy gases exerted from the volcano of (Ponotova) in Philippine one year before the mentioned eclipse. Solar Eclipse The most amazing astronomic event that may be seen in naked eye from earth is the solar eclipse especially the total eclipse, as it is an interesting event where the sun light hides in the daylight for a few minutes and the stars appear while the dark covers the sky. Solar eclipse happens when the moon exists in conjunction or Wane, which is contrary to the moon eclipse happening when the moon is full. Thus the difference between solar and lunar eclipse in case of taking place in the same months is 14 days, and when the moon is wane; then it prevents sunrays from reaching specific areas on earth in solar eclipse, and the areas having moon shade are the one witnessing eclipse. Solar eclipse does not happen the moon is wane; because of the moon orbit tilt to the horoscopes’ circle by 5 degrees and 9 minutes, but in some cases the moon orbit is compatible with the horoscopes circle when it is wane, thus solar eclipse takes place. Solar eclipse may be divided into three forms, which are: 1- Total solar eclipse; which happens in case the moon covers the entire sun, which is the most exciting cases of eclipse. Total eclipse does not happen for more than 7 minutes and 31 seconds; although no solar eclipse was observed taking that period until now. The longest solar eclipse observed until now is the one that took place in Philippine on 20/06/1955, which extended for 7 minutes and 8 seconds. The period of total solar eclipse is calculated for a person on earth; whereas the moon shades passes in a specific velocity reaching 3000 kilometers per hour, and it passes several thousands of kilometers during total eclipse; but for a person standing on earth, he only sees it for a few minutes. Considering that the period of total solar eclipse does not exceed a few minutes, which is an adequate period for studying the eclipse and resulting scientific phenomena; astronomers usually refer to using the air jet plane with speed of 3000 kilometers per hour, which is the velocity of moon shade in passing earth surface, in order to observe eclipse during total phase for 70 minutes. The best example for that is the total eclipse that took place on 30 June 1992, as the shade started passing on earth surface at 9:50 and ended on 14:29, i.e. it extended for around 5 hours, but the person standing on earth sees total eclipse for 5 minutes and 20 seconds. During total solar eclipse, strange natural phenomena happen; whereas temperature decreases, dark is spread and stars appear bright and planets shining; while comets close to the sun might appear, which may not be seen unless upon solar eclipse, accompanied by wind, animals hiding in their warrens and bird return to their nests while insects star wheezing. It is not good to look directly to partial solar eclipse unless using protective glasses for observation. In case the person observes partial eclipse; that would lead to losing sight permanently because of the rays exerted from the sun; such as UV and infrared that harm the retina. Human in the past used to become terrified once solar eclipse takes place; as he used to think that a huge monster or dragon has swallowed the sun or that a huge celestial body hit it and the end of universe is about to happen. They used to think that solar eclipse happens to cause natural disasters such as earthquakes, volcanoes, floods and the death of famous persons; but Islam indicated the false beliefs as when Ibrahim the son of prophet Mohammed PBUH died, the sun witnessed eclipse, and some people thought that the two events are related to each other, but the prophet said : “The sun and the moon are two signs of Allah; they are not eclipsed on account of anyones death or on account of anyone's birth.”. 2- Annular solar eclipse Annular eclipse takes place when the moon is in peak point; i.e. in the farthest point from earth, thus it appears relatively small. When the eclipse happens the moon does not cover the entire sun, as it appears bigger than the moon and its sides appear around it like a shining circle, this is considered a very beautiful eclipse. 3- Partial solar eclipse In this type of eclipse, the moon hides part of sun circle thus the eclipse is partial. It is an event that might be interesting for amateurs but it is not that important in case the percentage of hiding sun is little.
