Solar eclipsesA solar eclipse occurs when the Moon comes in between the Sun and also the observer. This happens as soon as the zero cone that the Moon intersects the surface of the Earth, and also is observable by anyone in ~ this shadow zone.
You are watching: What conditions are necessary for a lunar eclipse to occur
Two conditions have to be met because that a solar eclipse come occur. The very first concerns the relationship in between the orbits of Earth and the Moon, which space not in the very same plane, however are lean at around 5 degrees (5 degrees 8" 43") to every other. The Moon the cross the aircraft of Earth"s orbit twice in each finish orbit. For an eclipse to occur the Moon need to be close to one of these intersection point out (or nodes).
The second condition is that the Sun, Earth and also the Moon must additionally be lined up, equivalent to the phase of the brand-new Moon.
Types the solar eclipses: annular, partial, total
The Moon"s shadow consists of two cone-shaped locations (see number 1), known as the umbra (externally tangent to the Sun and Moon) and also the penumbra (internally tangent come the Sun and also Moon). For an observer standing between the Moon and the umbra cone summit the eclipse is total. If the observer is beyond the cone summit, the eclipse is annular (ring-like): the apparent diameter of the Moon is too little to mask the whole solar disk. For an observer standing in the penumbra, just a component of the sunlight is masked: the eclipse is partial.
The most favourable conditions for a full eclipse are when the Moon is in ~ its perigee, earth is farthest from the sunlight (around July) and also when the sunlight is observed near zenith. As soon as these problems are every met, one can have a totality duration of an ext than seven minutes.
What is a lunar eclipse?
A lunar eclipse occurs when planet comes between the Sun and the Moon. This phenomenon deserve to be viewed by any observer on earth for who the Moon is over the horizon, and also so is much more frequent. Lunar eclipses occur at the time of a full Moon, and also when the Moon is near one that the nodes the intersection between its orbit and also the ecliptic plane.
Earth"s umbra is bigger than the entirety Moon. So, one will certainly observe either a total eclipse by the umbra (which deserve to be well observed), a partial eclipse by the umbra and penumbra, or a complete or partial eclipse by the penumbra only. The duration of a lunar eclipse is much much longer than a solar eclipse, and also can take it as much as 6 hours.
See more: How Does Certo Clean Your System, Sure Jell Aka Certo Drug Test Detox
In practice, the lunar eclipse problems are modified because of the refraction of the Sun"s rays by Earth"s atmosphere. This refraction (of 35 minute of arc) permits some light to pass through the cone of geometric umbra. So also during complete lunar eclipse, the lunar decaying is not completely dark. This grazing irradiate is more absorbed by Earth"s environment in the blue and yellow sections of the spectrum, providing a certain reddish irradiate during complete lunar eclipse.