question: Why is a new moon different from a lunar eclipse?
comment: They're actually the opposite, pretty much. A lunar eclipse is only possible when the earth is between the moon and the sun -- that is, during the full moon phase. A new moon is the other way around, with the moon between the earth and the sun. A new and full moon happen *whenever* the moon is on the same side of Earth as the sun or the opposite side, respectively. A lunar and solar *eclipse,* by contrast, can only occur when the earth, moon, and sun are directly in line, or very nearly so.
passages: If a solar eclipse occurs at one new moon, which must be close to a node, then at the next full moon the Moon is already more than a day past its opposite node, and may or may not miss the Earth's shadow. By the next new moon it is even further ahead of the node, so it is less likely that there will be a solar eclipse somewhere on Earth. By the next month, there will certainly be no event.
   If the Moon were in a perfectly circular orbit, a little closer to the Earth, and in the same orbital plane, there would be total solar eclipses every new moon. However, since the Moon's orbit is tilted at more than 5 degrees to the Earth's orbit around the Sun, its shadow usually misses Earth. A solar eclipse can only occur when the moon is close enough to the ecliptic plane during a new moon. Special conditions must occur for the two events to coincide because the Moon's orbit crosses the ecliptic at its orbital nodes twice every draconic month (27.212220 days) while a new moon occurs one every synodic month (29.530587981 days). Solar (and lunar) eclipses therefore happen only during eclipse seasons resulting in at least two, and up to five, solar eclipses each year; no more than two of which can be total eclipses.
   New moon
  
  In astronomy, the new moon is the first lunar phase, when the Moon and Sun have the same ecliptic longitude. At this phase, the lunar disk is not visible to the unaided eye, except when silhouetted during a solar eclipse. Daylight outshines the earthlight that dimly illuminates the new moon. The actual phase is usually a very thin crescent.
   BULLET::::- 30.50011 eclipse years (61 eclipse seasons)
  
  BULLET::::- 383.67351 anomalistic months.
  
  BULLET::::- 8 eclipse sets
  
  The 30.5 eclipse years means that if there is a solar eclipse (or lunar eclipse), then after one inex a New Moon (resp. Full Moon) will take place at the opposite node of the orbit of the Moon, and under these circumstances another eclipse can occur.
   It might be expected that once every month, when the Moon passes between Earth and the Sun during a new moon, its shadow would fall on Earth causing a solar eclipse, but this does not happen every month. Nor is it true that during every full moon, the Earth's shadow falls on the Moon, causing a lunar eclipse. Solar and lunar eclipses are not observed "every" month because the plane of the Moon's orbit around the Earth is tilted by about 5° with respect to the plane of Earth's orbit around the Sun (the plane of the ecliptic). Thus, when new and full moons occur, the Moon usually lies to the north or south of a direct line through the Earth and Sun. Although an eclipse can only occur when the Moon is either new (solar) or full (lunar), it must also be positioned very near the intersection of Earth's orbital plane about the Sun and the Moon's orbital plane about the Earth (that is, at one of its nodes). This happens about twice per year, and so there are between four and seven eclipses in a calendar year. Most of these eclipses are partial; total eclipses of the Moon or Sun are less frequent.
   In calendric contexts, "new moon" refers to the first visible crescent of the Moon, after conjunction with the Sun. This takes place over the western horizon in a brief period between sunset and moonset, and therefore the precise time and even the date of the appearance of the new moon by this definition will be influenced by the geographical location of the observer. The astronomical new moon, sometimes known as the "dark moon" to avoid confusion, occurs by definition at the moment of conjunction in ecliptical longitude with the Sun, when the Moon is invisible from the Earth. This moment is unique and does not depend on location, and in certain circumstances it coincides with a solar eclipse.
   Total eclipses are rare because the timing of the new moon within the eclipse season needs to be more exact for an alignment between the observer (on Earth) and the centers of the Sun and Moon. In addition, the elliptical orbit of the Moon often takes it far enough away from Earth that its apparent size is not large enough to block the Sun entirely. Total solar eclipses are rare at any particular location because totality exists only along a narrow path on the Earth's surface traced by the Moon's full shadow or umbra.
   Eclipses only occur when the Sun, Earth, and Moon are all in a straight line (termed "syzygy"). Solar eclipses occur at new moon, when the Moon is between the Sun and Earth. In contrast, lunar eclipses occur at full moon, when Earth is between the Sun and Moon. The apparent size of the Moon is roughly the same as that of the Sun, with both being viewed at close to one-half a degree wide. The Sun is much larger than the Moon but it is the vastly greater distance that gives it the same apparent size as the much closer and much smaller Moon from the perspective of Earth. The variations in apparent size, due to the non-circular orbits, are nearly the same as well, though occurring in different cycles. This makes possible both total (with the Moon appearing larger than the Sun) and annular (with the Moon appearing smaller than the Sun) solar eclipses. In a total eclipse, the Moon completely covers the disc of the Sun and the solar corona becomes visible to the naked eye. Because the distance between the Moon and Earth is very slowly increasing over time, the angular diameter of the Moon is decreasing. Also, as it evolves toward becoming a red giant, the size of the Sun, and its apparent diameter in the sky, are slowly increasing. The combination of these two changes means that hundreds of millions of years ago, the Moon would always completely cover the Sun on solar eclipses, and no annular eclipses were possible. Likewise, hundreds of millions of years in the future, the Moon will no longer cover the Sun completely, and total solar eclipses will not occur.
   The Moon's orbit intersects with the ecliptic at the two nodes that are 180 degrees apart. Therefore, the new moon occurs close to the nodes at two periods of the year approximately six months (173.3 days) apart, known as eclipse seasons, and there will always be at least one solar eclipse during these periods. Sometimes the new moon occurs close enough to a node during two consecutive months to eclipse the Sun on both occasions in two partial eclipses. This means that, in any given year, there will always be at least two solar eclipses, and there can be as many as five.
   Between 1901 and 2100 there are the maximum of seven eclipses in:
  
  BULLET::::- four (penumbral) lunar and three solar eclipses: 1908, 2038.
  
  BULLET::::- four solar and three lunar eclipses: 1918, 1973, 2094.
  
  BULLET::::- five solar and two lunar eclipses: 1934.
  
  Excluding penumbral lunar eclipses, there are a maximum of seven eclipses in:
  
  BULLET::::- 1591, 1656, 1787, 1805, 1918, 1935, 1982, and 2094.
  
  Section::::Earth–Moon system.:Solar eclipse.
   BULLET::::- Fortnight: Half a synodic month (29.53 days). When there is an eclipse, there is a fair chance that at the next syzygy there will be another eclipse: the Sun and Moon will have moved about 15° with respect to the nodes (the Moon being opposite to where it was the previous time), but the luminaries may still be within bounds to make an eclipse.For example, partial solar eclipse of June 1, 2011 is followed by the total lunar eclipse of June 15, 2011 and partial solar eclipse of July 1, 2011.
   An eclipse does not happen at every new or full moon, because the plane of the orbit of the Moon around the Earth is tilted with respect to the plane of the orbit of the Earth around the Sun (the ecliptic): so as seen from the Earth, when the Moon is nearest to the Sun (new moon) or at largest distance (full moon), the three bodies usually are not exactly on the same line.
   However, about 5 or 6 lunations later the new moon will fall close to the opposite node. In that time (half an eclipse year) the Sun will have moved to the opposite node too, so the circumstances will again be suitable for one or more eclipses.
  
  Section::::Periodicity.
   BULLET::::- In the fourth arc of the "Sailor Moon" manga series by Naoko Takeuchi and the fourth season of its anime adaptation, two eclipses grant power to the group of antagonists known as Dead Moon Circus.
   where "N" is the number of full moons since the first full moon of 2000. The true time of a full moon may differ from this approximation by up to about 14.5 hours as a result of the non-circularity of the Moon's orbit. See New moon for an explanation of the formula and its parameters.
  
  The age and apparent size of the full moon vary in a cycle of just under 14 synodic months, which has been referred to as a full moon cycle.
  
  Section::::Characteristics.:Lunar eclipses.
   The eclipse magnitude varies not only between eclipses, but also by viewing location. An eclipse may be annular in one location and total in another. These mixed-type eclipses are called hybrid.
  
  Section::::Effect of the magnitude on a lunar eclipse.
   Solar eclipses starting near and within the polar areas are always partial, while solar eclipses starting at or within the equator are always total.
  
  Section::::Penumbral shadow.
  
  In its eclipses, the penumbral shadow does not appear until it is around 25–30% obscuration. It becomes slightly darker when the Earth blocks the sunlight until it reaches totality in some eclipses.
   Total lunar eclipses which fall on supermoon and micromoon days are relatively rare. In the 21st century, there are 87 total lunar eclipses, of which 28 are supermoons and 6 are micromoons. Almost all total lunar eclipses in Lunar Saros 129 are micromoon eclipses.
  
  Section::::See also.
  
  BULLET::::- Apsis
  
  BULLET::::- Moon illusion
  
  BULLET::::- Syzygy (astronomy)
  
  Section::::External links.
  
  BULLET::::- Lunar Apogee/Perigee Calculator 
  
  BULLET::::- Richard Nolle's definition
  
  BULLET::::- Richard Nolle's list of supermoon's in the 21st century
  
  BULLET::::- Full Moon at Perigee (Super Moon): 2001 to 2100 (Fred Espenak)
  
  BULLET::::- Super Blue Blood Moon 2018 | Check123 1 Minute Video
   The phases observed during a total eclipse are called:
  
  BULLET::::- First contact—when the Moon's limb (edge) is exactly tangential to the Sun's limb.
  
  BULLET::::- Second contact—starting with Baily's Beads (caused by light shining through valleys on the Moon's surface) and the diamond ring effect. Almost the entire disk is covered.
  
  BULLET::::- Totality—the Moon obscures the entire disk of the Sun and only the solar corona is visible.
  
  BULLET::::- Third contact—when the first bright light becomes visible and the Moon's shadow is moving away from the observer. Again a diamond ring may be observed.
   BULLET::::- An annular eclipse occurs when the Sun and Moon are exactly in line with the Earth, but the apparent size of the Moon is smaller than that of the Sun. Hence the Sun appears as a very bright ring, or annulus, surrounding the dark disk of the Moon.
  
  BULLET::::- A hybrid eclipse (also called annular/total eclipse) shifts between a total and annular eclipse. At certain points on the surface of Earth, it appears as a total eclipse, whereas at other points it appears as annular. Hybrid eclipses are comparatively rare.
   The original meaning of the term "new moon", which is still sometimes used in non-astronomical contexts, was the first visible crescent of the Moon, after conjunction with the Sun. This crescent moon is briefly visible when low above the western horizon shortly after sunset and before moonset.
   A solar eclipse occurs when the Moon passes between the Earth and the Sun, casting a shadow on Earth that temporarily obscures part or all of the Sun's disc. Eclipses can occur only when all three bodies are properly aligned. Partial eclipses, in which only a portion of the Sun's surface is obscured, are relatively common due to the width of the Moon's outer shadow, or penumbra, which may be several hundred miles wide. Total eclipses occur when the Moon's inner shadow, or umbra, reaches the surface of the Earth, completely obscuring the Sun over a much narrower portion of the ground. If the Moon is too far away at the time of an eclipse, its umbra may not reach the Earth's surface, and only a partial eclipse will be visible.
   Because the Earth's orbit around the Sun is also elliptical, the Earth's distance from the Sun similarly varies throughout the year. This affects the apparent size of the Sun in the same way, but not as much as does the Moon's varying distance from Earth. When Earth approaches its farthest distance from the Sun in early July, a total eclipse is somewhat more likely, whereas conditions favour an annular eclipse when Earth approaches its closest distance to the Sun in early January.
  
  Section::::Types.:Terminology for central eclipse.
   Total solar eclipses are seen on Earth because of a fortuitous combination of circumstances. Even on Earth, the diversity of eclipses familiar to people today is a temporary (on a geological time scale) phenomenon. Hundreds of millions of years in the past, the Moon was closer to the Earth and therefore apparently larger, so every solar eclipse was total or partial, and there were no annular eclipses. Due to tidal acceleration, the orbit of the Moon around the Earth becomes approximately 3.8 cm more distant each year. Millions of years in the future, the Moon will be too far away to fully occlude the Sun, and no total eclipses will occur. In the same timeframe, the Sun may become brighter, making it appear larger in size. Estimates of the when the moon will be unable to occlude the entire Sun when viewed from the Earth range between 650 million and 1.4 billion years in the future.
   When the Moon moves into Earth's shadow, a lunar eclipse occurs, during which all or part of the Moon's face may appear reddish due to the Rayleigh scattering of blue wavelengths and the refraction of sunlight through Earth's atmosphere. Lunar eclipses happen only during full moon and around points on its orbit where the satellite may pass through the planet's shadow. A lunar eclipse does not occur every month because the Moon's orbit is inclined 5.14° with respect to the ecliptic plane of Earth; thus, the Moon usually passes north or south of Earth's shadow, which is mostly restricted to this plane of reference. Lunar eclipses happen only when the full moon occurs around either node of its orbit (ascending or descending). Therefore, a lunar eclipse occurs about every six months, and often two weeks before or after a solar eclipse, which occurs during new moon around the opposite node.
  