Why does the Moon turn red during a lunar eclipse: NASA explains

New Delhi, Nov 05: The year 2022 is set to witness the last total lunar eclipse on Tuesday. There will not be another full lunar eclipse until 2025 says NASA.

There would however be partial and penumbral eclipses during this period. Thanks to this eclipse we will be able to witness the ice giant planet Uranus in the sky as the dim Moon will pave way for other celestial bodies to shine better.

A lunar eclipse occurs when the Sun, Earth and Moon are aligned. The Earth falls between the two and the Moon passes into the Earth's shadow briefly. It is normally understood that the energy of the Sun which reaches the Earth in the form of radiation is seen by the human eye as visible light which has wavelengths.

"The same phenomenon that makes our sky blue and our sunsets red causes the Moon to turn red during a lunar eclipse. It's called Rayleigh scattering. Light travels in waves, and different colours of light have different physical properties. 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," NASA said in a post on its website.

The blue colour travelling in shorter, smaller waves makes it easy to get scattered by particles and dust but during the sunset , sunlight reaches us from low in the sky, travelling father before reaching our eyes. It passes through more air and particles scattering and rescattering blue light many times, in many other directions. Hence it is removed from the atmosphere, allowing red, orange and yellow colours with larger wavelengths to go through.