The night sky offers few sights as captivating as the Earth’s shadow falling across the lunar surface. On March 3, skywatchers are in for a treat as a total lunar eclipse takes centre stage.
This event occurs when the Earth moves directly between the Sun and the Moon, casting its shadow across the lunar surface.
While both partial and total lunar eclipses involve the same celestial mechanics, the visual results are dramatically different.
Understanding these variations depends entirely on how deep the Moon dives into the shadow cast by our planet.
WHAT HAPPENS DURING A TOTAL LUNAR ECLIPSE?
A total lunar eclipse occurs when the entire Moon enters the innermost part of the Earth’s shadow, known as the umbra.
This is exactly what will happen on March 3. In India, the Moon will rise while already immersed in this shadow.
During this event, the Moon does not vanish into darkness. Instead, it often takes on a striking copper or dark red hue. This is why a total lunar eclipse is also known as a Blood Moon.
This phenomenon is caused by Rayleigh scattering, where the Earth’s atmosphere filters out shorter blue light and allows longer red wavelengths to pass through and bend towards the Moon.
The intensity of this red colour can change based on the amount of dust or clouds in the Earth’s atmosphere at that moment.
Because the Earth is significantly larger than the Moon, a total eclipse can last for over an hour, allowing viewers across the night side of the globe to witness the full transformation.
HOW IS A PARTIAL LUNAR ECLIPSE DIFFERENT?
A partial lunar eclipse happens when the Sun, Earth, and Moon are not perfectly aligned.
In this scenario, only a fraction of the Moon passes into the dark umbral shadow. To an observer on Earth, it looks as though a giant bite has been taken out of the Moon.
The part of the Moon inside the umbra appears very dark, while the rest remains bright or slightly dimmed by the penumbra, which is the outer, lighter part of the shadow.
Unlike the total version, a partial eclipse rarely produces the famous red glow, as enough direct sunlight still reaches the lunar surface to maintain its usual greyish white appearance.
HOW CAN YOU TELL WHICH ECLIPSE IS OCCURRING?
The easiest way to distinguish them is by looking at the coverage of the lunar disk. During a total eclipse, 100 per cent of the Moon will eventually be covered by the dark umbra, leading to the reddening phase. In a partial eclipse, the coverage never reaches 100 per cent.
Regardless of the type, both events are safe to view with the naked eye. While a total eclipse like the one on March 3 is the headline act, a partial eclipse provides a clear view of the Earth’s curved shape as it blocks the Sun’s light.
