Eclipses are intriguing celestial events that have fascinated mankind since ancient times. They take two forms – Lunar and Solar, both of which are determined by the positions of the Sun, the Earth, and the Moon. On 8th November 2022, we witnessed a Total Lunar Eclipse following the Partial Solar Eclipse observed in India in October 2022. These phenomena merit further exploration and understanding.
Demystifying Lunar Eclipse
A lunar eclipse occurs when the Moon moves into the Earth’s shadow, creating a spectacle where the Earth is positioned directly between the Sun and the Moon. This event can only take place during a full moon phase.
Initially, the moon travels into the penumbra, a part of the Earth’s shadow where not all sunlight is blocked. During this stage, a portion of the moon’s disk appears dimmer than a typical full moon. Subsequently, the moon enters the Earth’s umbra, an area where direct sunlight is completely blocked by the Earth. Here, the only light reflecting off the moon’s disc has been refracted or bent, by our planet’s atmosphere.
Total Lunar Eclipse and Its Characteristics
In a Total Lunar Eclipse, the entire lunar disc enters the Earth’s umbra, causing the moon to appear reddish, often referred to as a “Blood Moon”. This extraordinary color change is due to a phenomenon known as Rayleigh scattering.
Rayleigh scattering involves the scattering of light by particles within a medium without any change in wavelength. The same principle makes our sky appear blue. However, during a total lunar eclipse, the sunlight reaching the moon passes through the Earth’s atmosphere and scatters due to the dust or clouds present therein, resulting in the moon’s red hue. Statistics from NASA reveal that total lunar eclipses occur approximately once every 18 months.
Partial and Penumbral Lunar Eclipses
In contrast to a Total Lunar Eclipse, a Partial Lunar Eclipse arises from an imperfect alignment of the Sun, Earth, and Moon. Here, the moon only traverses a portion of Earth’s umbra, giving rise to a shadow that grows and recedes without entirely covering the moon.
During a Penumbral Eclipse, the moon glides through the Earth’s penumbra or the faint outer part of its shadow. The resulting dimming effect on the moon can be slight and hardly noticeable.
An Overview of Solar Eclipses
A solar eclipse, unlike its lunar counterpart, happens when the Moon, located between the Sun and Earth, casts a shadow on our planet. This shadow either fully or partially obstructs the Sun’s light in certain areas.
Diverse Types of Solar Eclipses
Total Solar Eclipses transpire when the New Moon comes between the Sun and Earth, casting its darkest shadow, the umbra, onto our world. At such times, the Moon entirely obscures the disk of the Sun, making it dark as night and causing temperatures to drop.
Annular Solar Eclipses occur when the Moon, positioned between the Sun and Earth, is at or near its farthest point from Earth. The Moon appears smaller than the Sun due to its distance and does not completely cover it, forming what looks like a ring around the moon.
Partial Solar Eclipses happen when the Moon is not perfectly aligned with the Sun and Earth, causing only a part of the sun to become obscured and appearing crescent-shaped.
Lastly, Hybrid Solar Eclipses occur due to the curvature of Earth’s surface, causing the eclipse to fluctuate between being annular and total as the Moon’s shadow traverses across the globe.
