27, Jul 2018
The month of July is set to witness a rare astronomical spectacle as a blood moon, the second of the year, will appear on the intermediary night of July 27-28.
The ‘Marathon’ Eclipse:
According to space experts, the eclipse will last one hour and 43 minutes – nearly 40 minutes longer than the January 31 Super Blue Blood Moon.
Why will the moon turn red?
- The blood moon, or the ‘full buck moon’ as it is being called, will turn blood red during the eclipse due to the way light bends around Earth’s atmosphere.
- During a blood moon, the moon takes on a deep red to orange colour, rather than completely disappearing when it passes through the shadow cast by Earth.
- This bizarre effect known as ‘Rayleigh scattering’ filters out bands of green and violet light in the atmosphere during an eclipse.
Why will this lunar eclipse be longer?
- The full buck moon will last longer than normal as it will pass almost directly through Earth’s shadow during the eclipse.
- At the same time, it will be at the maximum distant point from earth. Therefore, it will take longer to cross Earth’s shadow.
The dispersion of electromagnetic Radiation by particles that have a radius less than approximately 1/10 the wavelength of the radiation. The angle through which sunlight in the atmosphere is scattered by molecules of the constituent gases varies inversely as the fourth power of the wavelength; hence, blue light, which is at the short wavelength end of the visible spectrum, will be scattered much more strongly than will the long wavelength red light.