A total lunar eclipse explained, and you can see one soon enough

• Eclipses and transits are spectacular events in the space happening when a celestial body covers another, partially or totally.
  
  
• The two interesting eclipses viewable from the Earth are solar and lunar eclipses.
  
  
• A total lunar eclipse results when the central and darkest part of the Earth’s shadow known as umbra covers the entire surface of the Moon.
  

Due to their rarity and spectacular nature, eclipses have always evoked the imaginations and interests of humans. Eclipses, also known as transits, happen when a celestial body partially or fully covers another during its movement. The two popular kinds of eclipses we can see from the Earth are solar and lunar eclipses.

How does a lunar eclipse happen?

Moon is a satellite of the Earth and it goes around the earth once in a lunar month, roughly about 29.5 days. The Moon does not have natural light of its own. It glows only because of reflecting the Sun’s light. When the Earth comes in between the Moon and the Sun, its shadow blocks the Sun’s rays lighting up the Moon and hence a lunar eclipse happens. A lunar eclipse can happen only on a full Moon day since for a lunar eclipse to happen, the Moon, the Earth and the Sun must be aligned in a straight line.

What is a total lunar eclipse?

Eclipses can be total, partial or penumbral. When only a part of the Earth’s shadow covers the Moon, we can see a partial lunar eclipse. If the Moon travels through the penumbral (faint) part of the Earth’s shadow, a penumbral lunar eclipse happens. Total lunar eclipse happens when the central and the darkest part of the Earth’s shadow blocks the Sun’s light from reaching the Moon in entirety. In this process, the total surface of the Moon will become invisible or deeply shaded in red for a few minutes.

May 26, 2021 will see a total lunar eclipse

The first eclipse of the year 2021 will be a lunar eclipse happening on May 26, 2021. This lunar eclipse can be seen from India, south Asia, east Asia, Australia, and much of North America, South America, Pacific Ocean, Atlantic Ocean, Indian Ocean and Antarctica.

The May 26, 2021 lunar eclipse takes place within a few hours of the Moon reaching the closest point to the Earth. Hence, a spectacular show called a Super Flower Blood Moon will result.

The tetrad phenomenon

Including the lunar eclipse on May 26, there will be four big lunar eclipses in 2021 and 2022. Three of these eclipses will be total lunar eclipses while the one on November 18-19 in 2021 will be a partial one. However, it will also be a very deep one, making it an almost total eclipse. This is called the tetrad phenomenon.

The astronomical term for total eclipses

Total lunar eclipses happen only on Full Moon days when the Sun, the Earth, and the Moon are aligned in a straight line. Astronomy calls this kind of alignment as syzygy, the term derived from Greek language meaning ‘paired together’.