On the midnight of 27 July, more than half the world's population will get to witness the century's longest total lunar eclipse. The eclipse, which will last one hour and 43 minutes, will also feature a "blood moon" — which is a non-scientific term used to refer to the red tinge on a fully eclipsed Moon.
The eclipse will be visible in parts of South America, most of Africa, and West and Central Asia. For viewers in India, the eclipse, both partial and the total, will be visible in their entirety from all parts of the country. The partial eclipse of the Moon will start around 11.52 pm IST, with the total eclipse beginning at 1 am on 28 July.
Here is the detailed schedule of the movement of the moon during the eclipse (all times are IST):
Stage 1: Moon enters penumbra at 10.42 pm and 48 seconds on 27 July
Stage 2: Moon enters umbra at 11.52 pm and 52 seconds on 27 July
Stage 3: Start of totality at 12.59 am and 39 seconds on 28 July
Stage 4: Maximum eclipse at 1.51 am and 27 seconds on 28 July
Stage 5: End of totality at 2.43 am and 14 seconds on 28 July
Stage 6: Moon leaves umbra at 3.49 am and 2 seconds on 28 July
Stage 7: Moon leaves penumbra at 5 am and 5 seconds on 28 July
For a total lunar eclipse of a long duration to occur, the moon has to pass through the central part of the Earth's shadow.
The previous total lunar eclipse on 31 January lasted 1 hour and 16 minutes when the moon passed to the south of shadow's centre; and the next total lunar eclipse on 21 January, 2019 will be only for 1 hour and 2 minutes because it will pass to the north of the shadow's centre.
Late at night on 27 July, the full moon will be near its apogee — the farthest point from Earth in its orbit around Earth — and it will be the smallest full moon of the year.
The full moon will plunge deeply into the Earth's shadow on the night of 27-28 July. The distance of the Moon from Earth just before the eclipse will be around 4,06,223 kilometres.
Depending on atmospheric conditions, July's event could be an especially dark total lunar eclipse. The longest possible total lunar eclipse is 1 hour and 47 minutes — a rare phenomenon observed when the centre of the lunar disk aligns almost perfectly with the centre of the Earth's shadow.