From UPSC perspective, the following things are important :
Prelims level : Lunar and Solar Eclipse
Mains level : Not Much
A penumbral lunar eclipse will be observed today midnight. The Earth will imperfectly align itself between the Sun and the moon, casting a shadow on the latter, marking the second lunar eclipse of the year.
Solar and Lunar eclipse has been quite frequent this year. Mark the major differences between them.
- A lunar eclipse occurs when the Moon moves into the Earth’s shadow.
- This can occur only when the Sun, Earth, and Moon are exactly or very closely aligned with Earth between the other two.
- A lunar eclipse can occur only on the night of a full moon. The type and length of a lunar eclipse depend on the Moon’s proximity to either node of its orbit.
- Any object that obstructs light will produce two shadows: one which will be dark and dense, is called the umbra; and the other which is light and diffused is called the penumbra.
- The only light reflected from the lunar surface has been refracted by Earth’s atmosphere.
- This light appears reddish for the same reason that a sunset or sunrise does: the Rayleigh scattering of bluer light. Due to this reddish colour, a totally eclipsed Moon is sometimes called a blood moon.
- In a total eclipse of the moon, the inner part of Earth’s shadow, called the umbra, falls on the moon’s face. At mid-eclipse, the entire moon is in shadow, which may appear blood red.
- In a partial lunar eclipse, the umbra takes a bite out of only a fraction of the moon. The dark bite grows larger and then recedes, never reaching the total phase.
- In a penumbral lunar eclipse, only the more diffuse outer shadow of Earth – the penumbra – falls on the moon’s face. This third kind of lunar eclipse is much more subtle and much more difficult to observe than either a total or partial eclipse of the moon.
How it is different from Solar Eclipse?
- A solar eclipse happens when the moon passes in between the earth and the sun. A lunar eclipse happens when the earth passes in between the moon and the sun.
- During a solar eclipse, the moon partially or fully hides the sun’s rays for a few minutes.
- Unlike a solar eclipse, which can only be viewed from a relatively small area of the world, a lunar eclipse may be viewed from anywhere on the night side of Earth.
- Also unlike solar eclipses, lunar eclipses are safe to view without any eye protection or special precautions, as they are dimmer than the full Moon.
What’s special this time?
- This eclipse is also called a strawberry moon eclipse — the term, interestingly, originates from an American concept and has little to do with the Euro-Asia region.
- June’s full moon usually coincides with the harvesting season of wild strawberries in America and the phenomenon was often addressed in reference to that.
- India had already witnessed an eclipse earlier this year, in January.
- The strawberry moon eclipse is going to be its second and probably the last visible lunar one in 2020.