2nd lunar eclipse of 2018 is 21st century's longest

Hyderabad: The second lunar eclipse of the year, the longest of the 21st century, will begin at 11.54 pm on Friday and will last an hour and 43 minutes.

The eclipse in its various phases, invisible to the naked eye, begins at 10.45 pm and ends at 4.59 am on Saturday, July 28. The noticeable umbral phase begins at 11.54 pm and ends at 3.49 am. The totality phase, where the Earth’s shadow falls on the Moon, will start at 1 am and end at 2.43 am. 

Director, B.M. Birla Science Centre, Dr B.G. Siddharth said, “First will be the penumbral eclipse, invisible to many. The umbra eclipse where the shadow of the Earth falls on the moon and will be visible starts at 11.54 pm.” He said from that moment, more of the moon will get covered by the Earth till totality occurs at 3.49 am.

“Theoretically, the moon should disappear since it is blocked by the earth, but this does not happen, because the Earth’s inclined position allows light to reach the moon. Thus there will be some light into the dark shadow region of the moon.”

He said that the inclination of the Earth will scatter the sun’s rays, leaving the moon with a reddish brown colour. Thus it is called a blood moon, he said.

Once the Earth starts moving out of the straight line, the moon begins to emerge first as a cresent and then in its entirety on Saturday post 3.49 am. Sky gazers were apprehensive that clouds may obscure the eclipse. The bulletin said the monsoon currents were weak, which leaves open the prospect of clear skies.