A transit of Venus will take place on June 6.

The unique phenomenon occurs when Venus passes between the sun and earth and the planet gets aligned with the former.

This rare event occurs in pairs, eight years apart, about once a century. The next pair of transit will occur on December 11, 2117 and on December 8, 2125.

During the transit, the planet would appear as a black spot gliding across the sun's fiery face, Nehru Planetarium Director N. Rathnasree said.

The last transit occurred on June 8, 2004. It was visible from all parts of India.

The next transit of Venus will occur in 2117, making it once in a lifetime opportunity, Science Popularisation Association of Communicators and Educators Director C.B. Devgun said.

However, only the beginning phase of the event that comprises Ingress exterior, the point of the planet's first contact with the Sun's disk will be visible from India.

The Ingress interior, when Venus is fully inside the solar disc, will not be visible from any part of the country.

People in the eastern India can see the first part of the event after sunrise for about 5 hours 30 minutes, while those in western side will see it for about 4 hours 30 minutes.

The entire transit event will be visible from north western North America, the western Pacific, northern Asia, Japan, Korea, eastern China, Philippines, eastern Australia and New Zealand.

Partial lunar eclipse today

A partial lunar eclipse will grace the night sky on Monday but astronomy lovers in India will miss the event as the celestial phenomenon will not be visible from any part in the country. “The eclipse will be partly visible from western United States and Canada, while people in Hawaii, New Zealand, and central and eastern Australia will be able to follow the whole eclipse,” Mr. said. Total duration of the eclipse will be about two hours and seven minutes. A lunar eclipse occurs when the earth, in course of its orbit around the sun, comes between the moon and the sun in such a way that the moon is hidden in the shadow cast by the earth.