At a time when astronauts around the world are celebrating 50 years of Apollo 11 Luna landing, the moon will undergo a partial eclipse early morning on July 17. The spectacle can be seen when the moon passes partly but not completely through the earth’s dark umbral shadow.
Other than coinciding with the 50th anniversary of the Apollo mission, the eclipse is a little more special in India as it is falling at the same time as Guru Purnima — the first time after 149 years.
WHAT IS LUNAR ECLIPSE?
There are three basic types of lunar eclipses — Penumbral Lunar Eclipse, Partial Lunar Eclipse and Total Lunar Eclipse.
A lunar eclipse can only occur when a full moon passes through earth's shadow. The shadow is composed of two components, an outer shadow and an inner shadow. The outer or Penumbral shadow occurs when th earth blocks a part of the sun's rays from reaching the moon, while the inner or Umbral shadow is the region where the planet blocks all of the sun's rays.
A partial lunar eclipse occurs when the earth moves between the sun and the moon but they do not form a straight line. At such a time, a small part of the moon's surface is covered by the Umbra while the rest of the moon is covered by Penumbra.
According to astrophysicist Fred Espenak's predictions, the "greatest eclipse" — the instant when the moon passes the closest to the axis of the earth’s shadow cone — will start on July 17, 2019, at 3 am IST.
Courtesy: eclipsewise.com | Ciick on the image to enlargeThe event will cover South America, Europe, Africa, Asia and Australia. The North American region will be shut off as it will be daytime when the eclipse occurs.
PARTIAL LUNAR ECLIPSE TIME IN INDIA
In India, the eclipse can be witnessed on July 17 from 12.13 am and the maximum eclipse will be at 3 am. The moon will transit into partial eclipse at 1.30 am and will run for the duration of 2 hours and 58 minutes. It will enter the penumbral phase at 5.47 am.
The whole process will be 5 hours and 34 minutes long.
Unlike solar eclipses that are potentially dangerous to stare directly and may cause blindness, lunar eclipses are completely safe to look at with naked eye.
There is no need for wearing any eye protection; a good pair of binaculars and clear sky is enough to enjoy the experience. Anyone on the night side of the moon can witness the eclipse. Simply look at the sky and you may see a shadow seemingly taking a bite of the moon.
The next lunar eclipse, a complete one, will occur on May 26, 2021, while a partial one will take place on November 19, 2021.