Blue Moon, Big Moon, Blood Moon Today

 On 31st January 2018 a total lunar Eclipse

The plane in which the Earth moves around the Sun is known as ecliptic plane. The Moon moves in a smaller orbit around the Earth. The plane of the Moon’s orbit is not aligned with the ecliptic, but it is inclined to the ecliptic plane by about 5 degrees. Because of this, only very rarely, the moon crosses the imaginary line connecting the Sun and the Earth. Whenever this happens, an eclipse of the Sun takes place. Had this plane of the Moon aligned with the ecliptic plane, every new moon day an eclipse of the Sun would have occurred and every full moon day an eclipse of the Moon would have occurred.

When the Moon moves in the shadow of the Earth, it is known as the eclipse of the Moon or lunar eclipse. Lunar eclipses can take place only during particular full-moon days, when the Moon comes diametrically opposite to the position of the Sun, as viewed from the Earth. Only very rarely, the moon reaches the imaginary line connecting the Sun and the Earth and crosses the Earth’s shadow in space. During other full moon days, the Moon will pass above or below the Earth’s shadow, hence no eclipse results. The shadow of the Earth cast by the Sunlight will have two components. One is darker shadow or umbra and the other is lighter shadow or penumbra. When the entire disk of the Moon crosses the darker shadow. the eclipse is known as total lunar eclipse.

The eclipse will be visible in India. most of western North America, eastern Asia. Australia, and the Pacific Ocean. The partial phase begins at 17:18 hrs (1ST), Total Phase begins at 18:21 hrs (1ST), Greatest eclipse is at 18:59 hrs (1ST), total phase ends at 19:38 hrs (1ST) and the partial phase finally ends at 20:41 hrs (1ST). Total phase will be visible in India. In Chennai the Moon, with partial eclipse, will rise at 18:04 hrs (1ST). Lunar eclipses can be observed without telescopes, from an open space. Observing a lunar eclipse with naked eye will not cause harm.

At B. M. Birla Planetarium, Periyar Science and Technology Centre, Gandhi-mandapam Road, Chennai-25, elaborate arrangements are being made for the public to witness the lunar eclipse on 31st ‘ January 2018 from 6:30 p.m. to 10 p.m.

Another total eclipse of the Moon can be seen from India on the night of 27th July 2018 to early hours of 28th July 2018. Incidentally, today the Moon will also appear slightly bigger as the Moon is almost near the closest Point to the Earth on its elliptical orbit. This will be the last of two supermoons for 2018 (earlier one was on 2nd January 2018). The Moon was at its closest approach yesterday.

Today it will be at a distance of 3,64.507 km from the Earth Since this is the second full moon in the same month, it is referred to as a blue moon. Again, in the month of March there will be two full moons. The full moon of 31st March 2018 will be the next blue moon. Having a total lunar Eclipse on Blue Moon is very rare. This occurs after a span of about 150 years. In the past on March 31. 1866 such event occurred. Again on December 31, 2028 a Blue moon lunar Eclipse will occur.

31st January 2018 a total lunar Eclipse
31st January 2018 a total lunar Eclipse