Spring 4, 461 AV Nashira was sitting against the front door of the cottage she shared with Caleb. Its hard wood supporting her back as she curled her knees into her chest, and allowed her bare feet to rest firmly on the ground. They were resting upon a tuft of green grass, which tickled their soles. Her eyes danced over the pages of the book she had balanced in her lap- the one she had been reading the day before, the one her teacher had lent her until further notice. In her left hand, she held a slender white candle, crafted of wax that dripped all too rapidly for her liking when a flickering orange flame caught is wick. Blackening it as the molten clear pool of wax fell over the sides and onto her hands. Upon reaching her flesh, the hot wax stung, before cooling and soothing the pain it had once caused. It seemed to be gathering now into a small hill of greyish-white, but the Ethaefal did not mind. Although the nearly full moon cast nearly enough light to illuminate the pages of her text, it alone, was not enough to allow for her to continue on in her studies. As she read, Nashira would turn the pages with her right hand, if the wind did not offer its services, doing more than simply whistling in her ears, or winding the edges of her long brown hair around her shoulders. At times, the winds were blocked completely by the side of the house, and the noise it produced failed to bother her, so intent was she on her reading, the completion of the latest chapter in her book. Since the day before, she had finished the portion of the book that was devoted to the classification of the solar eclipse, and moved onto a chapter devoted to the lunar eclipse, it read: A lunar eclipse occurs when the moon passes behind the planet we live upon, causing the planet to block the sun's rays, thus, keeping them from reaching the moon. Such an event may only occur when the planet, sun and moon are aligned, or at the very least, are rather close to becoming aligned. The planet however, must be situated in the middle, between the other celestial orbs. Thus, a lunar eclipse may only occur during a full moon. "The type and length of an eclipse depend upon the Moon's location relative to its orbital nodes." Unlike a solar eclipse, which may only be viewed from a small portion of the world, a lunar eclipse can be viewed from any portion of the world which is shrouded in darkness. A lunar eclipse can last for a few hours, whereas a total solar eclipse will last for no more than a few minutes in any given place, due to the size of the moon's shadow. Types: The planet's shadow may be divided into two parts: the umbra and penumbra. Within the umbra, the planet falls to receive any direct sunlight. "However, as a result of the sun’s large angular size, solar illumination is only partially blocked in the outer portion of the planet’s shadow, which is given the name penumbra." A penumbral eclipse occurs when the Moon passes through the planet’s penumbra. The penumbra causes the surface of the moon to darken, but only slightly. A total penumbral eclipse occurs during the time in which the moon lies exclusively within the planet’s penumbra. Total penumbral eclipses are rare. They cause the section of the moon that lies closest to the umbra to appear marginally darker than the rest of the Moon. As seen by an observer who resides within Mizahar, the moon crosses the ecliptic upon the imaginary celestial sphere each time it orbits the planet, once it reaches a certain area, or position. These positions are called nodes, and are reached twice every month. When a full moon occurs in the same position at the node, a lunar eclipse may occur. The nodes allow for 2-5 lunar eclipses to occur each year, "parted by approximately six months." "A total penumbral lunar eclipse dims the moon in direct proportion to the area of the sun’s disk blocked by the planet." When merely a part of the moon enters the umbra, a partial lunar eclipse occurs. A total lunar eclipse occurs when the moon, in its entirety, is within the planet's umbra. It is estimated that the moon's speed, while traveling through the shadow is about one kilometer per second. However, some scientists believe it moves at about half that speed, while others still, believe that it moves far faster. Totality, then, has never been measured to exceed 107 minutes. Nevertheless, the amount of time between the moon’s initial and final contact with the shadow is far longer, and may last up to four hours, if not more. "The relative distance of the Moon from the planet at the time of an eclipse can affect the eclipse’s duration." More specifically, when the moon orbiting at is farthest point from the planet, it seems to move far more slowly than at other points in its orbit. "The diameter of the umbra does not decrease appreciably within the changes in the orbital distance of the moon. Thus, a totally eclipsed moon occurring near apogee will lengthen the duration of totality." Nashira raised her right hand, and wet a few fingers with her tongue, before lowering them to the page. The paper stuck to her fingertips as she turned it over, letting it flutter to a fall, before she continued her reading: The timing of a total lunar eclipse is determined the number of its contacts: First contact (P1) - This is the beginning of the penumbral eclipse. Beginning of the penumbral eclipse. The planet's penumbra meets with the moon's outer limb. Second contact (U1) - The partial eclipse commences. The planet's umbra meets with the moon's outer rim. Third contact (U2) - The first stages of a total eclipse occur. The surface of the moon is shrouded entirely within the planet's umbra. Greatest eclipse: The total eclipse at its peak. The moon as close to the center of the planet's umbra as it will get. Fourth contact (U3) - The total eclipse ceases. The outer limb of the moon leaves the planet's umbra. Fifth contact (U4) - The cessation of the partial eclipse. The planet's umbra comes away from the surface of the moon. Sixth contact (P2) - The sixth contact marks the end of the penumbral eclipse. The planet's shadow makes no further contact with the face of the moon. A selenelion "occurs when both the sun and the eclipsed moon can be observed at the same time." Such an even may only occur a few minutes prior to the setting of the sun, or shortly after sunrise. Both celestial orbs- the moon and the sun- will appear just above the horizon at opposing points in the sky. "This arrangement has led to the phenomenon being referred to as a horizontal eclipse." A horizontal eclipse occurs during every lunar eclipse, wherever a sunrise or a sunset is currently occurring on the planet. "Indeed, the reddened light that reaches the moon comes from all the simultaneous sunrises and sunsets on the planet. Although the moon is in the planet’s geometrical shadow, the sun and the eclipsed moon can appear in the sky at the same time because the refraction of light through the planet’s atmosphere causes objects near the horizon to appear higher in the sky than their true geometric position." Nashira turned the page again, before continuing: A scale used when rating the overall darkness of a lunar eclipse: "L=0: Very dark eclipse. Moon almost invisible, especially at mid-totality. L=1: Dark eclipse, gray or brownish in coloration. Details distinguishable only with difficulty. L=2: Deep red or rust-colored eclipse. Very dark central shadow, while outer edge of umbra is relatively bright. L=3: Brick-red eclipse. Umbral shadow usually has a bright or yellow rim. L=4: Very bright copper-red or orange eclipse. Umbral shadow is bluish and has a very bright rim." As Nashira finished reading the scale, she looked up at the sound of muffled footsteps upon the gravel. "Is that you Caleb?" she called, as she looked out in the night, portions of the world not yet touched by the moon's milky glow. OOCAgain, I used wikipedia as a source, and anything left in quotations was copied directly from the site. |