Chandra Grahan or Lunar Eclipse that occurs when the Sun, Moon, and Earth align, and the Moon moves into Earth's shadow is being observed today. The last total Lunar eclipse of 2022 has started and is visible in North America, the Pacific region, Australia, and Eastern Asia. In India, the Chandra Grahan is visible in cities like Delhi, Ranchi, Noida, Gurugram, Ahmedabad, Bengaluru, Patna, Vapi, Vijapur, Mumbai, Bhopal, Raipur, Lucknow, Chandigarh, Pune, etc.
While the totality period of the eclipse will be visible in Itanagar, Guwahati, Siliguri, Kolkata, and Bhubaneshwar, cities like Delhi, Srinagar, Chennai, Gandhinagar, and Mumbai will only be able to see the partial eclipse.
Why does the Moon turn red during a lunar eclipse? NASA explained that the same phenomenon which makes our sky blue and our sunsets red causes the Moon to turn red during a lunar eclipse. The phenomenon is called Rayleigh scattering. During the phenomenon light travels in waves, and different colors of light have different physical properties.
While blue light has a shorter wavelength and is scattered more easily by particles in Earth’s atmosphere than red light, which has a longer wavelength, red light travels more directly through the atmosphere.
When the Sun is overhead, we see blue light throughout the sky. But when the Sun sets, the sunlight passes through more atmosphere and travel farther before reaching our eyes. Therefore, the blue light from the Sun scatters away, and longer-wavelength red, orange, and yellow light passes through and reaches our eyes.
The Moon turns red during a lunar eclipse because the only sunlight reaching the Moon passes through Earth’s atmosphere. The more dust or clouds in Earth’s atmosphere during the eclipse, the redder the Moon appears. Lunar eclipses are also called “Blood Moons” because of this phenomenon.
Also read: Chandra Grahan 2022: Date, Timing In India, Sutak and other details of today's Lunar Eclipse
Also read: Lunar eclipse 2022 starts. When is the next total lunar eclipse?