PENUMBRAL LUNAR ECLIPSE - GEOGRAPHY
News: The
lunar eclipse on May 5 will be visible in India
What's in the news?
● Following
the hybrid solar eclipse on April 20, skywatchers in many parts of the world,
including India caught a glimpse of a penumbral lunar eclipse in action on May
5.
Key takeaways:
● Lunar
eclipses are not nearly as rare as solar eclipses.
● Once
or twice or more times every year, the
Earth, the Moon and the Sun line up in just the right way to create the
“shadowplay” that we call an eclipse, according to NASA.
Why lunar eclipse is more common than solar eclipse?
● The
reason this does not happen every month is because the Moon’s orbit around our planet is tilted relative to Earth’s orbit
around the Sun.
● This
means that the cosmic alignment does not happen each time the Moon makes a full
orbit around our planet.
Penumbral lunar eclipse:
● During
a penumbral eclipse, the Moon only travels through the Earth’s penumbra, which
is the faint outer part of its shadow.
● Due
to this, the Moon dims so slightly that you might actually miss it unless you
pay close attention.
● If
the full moon was exactly on the opposite side of the Earth with respect to the
Sun, there would be a total umbral eclipse of the Sun, completely blocking it
out.
Uniqueness of penumbral lunar eclipse:
● Unlike
other kinds of eclipses, penumbral lunar eclipses are subtle events that are
usually difficult to observe unless you pay very close attention.
Is it safe to view the lunar eclipse?
● Unlike
a solar eclipse, lunar eclipses are safe
to view with the naked eye and with other viewing equipment such as
binoculars or a telescope to get a better view of the eclipse.
How does a lunar eclipse happen?
● Lunar
eclipses only occur during a full moon.
● When
the Earth is situated precisely between
the Moon and the Sun. The Earth’s shadow falls on the Moon’s surface.
● This
dims or obscures the sunlight that is reflected by the Moon.
● Sometimes,
this dimming or obscuration can cause the Moon to turn slightly red.
Why does the Moon turn red during a lunar eclipse?
● During
some lunar eclipses, parts of the Moon obscured by the Earth’s shadow take on a
reddish tinge.
● This
is due to a phenomenon known as Rayleigh
scattering. Essentially, during those times, the only sunlight reaching the
Moon is the light that passes through our planet’s atmosphere first.
● Since
our atmosphere scatters the bluer wavelengths of light, only the redder part of
the light spectrum is let through.
Other kinds of lunar eclipses:
Total lunar eclipse:
● When
the Moon moves into the inner part of
the Earth’s shadow, or the umbra, it results in a total solar eclipse.
● Usually,
a total lunar eclipse is when the Moon appears to turn a shade of red.
● As
mentioned earlier, this is because of light passing through our planet,
reaching the Moon and Rayleigh scattering.
Partial lunar eclipse:
● When
the Sun, Earth and Moon align imperfectly, and only a portion of the Moon passes through the Earth’s umbra, you
get a partial lunar eclipse.
● During
a partial eclipse of the Moon, the dark shadow of the Earth will slowly grow on
the Moon, before it starts receding.
● The
dark shadow will not completely cover the Moon during a partial lunar eclipse.