What is a Penumbral Lunar Eclipse?
A penumbral lunar eclipse takes place when the Moon moves through the faint, outer part of the Earth’s shadow. This type of eclipse is often mistaken for a normal full Moon.
The Moon shines because its surface reflects the Sun rays. A lunar eclipse happens when the Earth comes between the Sun and the Moon and blocks sunlight from directly reaching the Moon.
A penumbral lunar eclipse occurs when the Sun, Earth and Moon align in an almost straight line. When this happens, the Earth blocks some of the Sun’s light from directly reaching the Moon’s surface, and covers a small part of the Moon with the outer part of its shadow, also known as the penumbra. The rest receives direct sunlight and can be as bright as a full Moon.
Because of this, it is often hard to differentiate between a normal full Moon and a penumbral eclipse of the Moon.
Conditions for a Penumbral Lunar Eclipse
Two celestial events must happen at the same time for a penumbral lunar eclipse to occur:
- the Moon should be a full Moon, and
- the Sun, Earth and Moon must be imperfectly aligned in a straight line.
How to see a Penumbral Lunar Eclipse?
Unlike solar eclipses, which can only be seen along a narrow path on Earth, eclipses of the Moon can be observed all across the night-side of Earth when the eclipse happens.
About one-thirds of all lunar eclipses are penumbral.
How to watch a lunar eclipse
Lunar eclipses are among the easiest skywatching events to observe. Simply go out, look up and enjoy. You don’t need a telescope or any other special equipment. However, binoculars or a small telescope will bring out details in the lunar surface — moonwatching is as interesting during an eclipse as anytime. If the eclipse occurs during winter, bundle up if you plan to be out for the duration — an eclipse can take a couple hours to unfold. Bring warm drinks and blankets or chairs for comfort.
And don`t forget to share this with a friend. 🙂