Metonic cycle is an astronomical period spanning 19 years, at the end of which, a new cycle starts with a new moon or a full moon and the sun and the moon returning to their original position vis-a-vis the earth and stars. The solar eclipse occurs only on a new moon day and lunar eclipse always on a full moon day.

The annular solar eclipse on the new moon day next week - when the sun appears like an annulus (or ring) - interestingly occurs exactly 19 years after the total solar eclipse, which was visible in India, on February 16, 1980.

The coincidence in the dates is also because of the end of the 19-year cycle, according to Hyderabad-based B M Birla Science Centre director, B G Siddharth. The country will miss the February 16 eclipse, as it will be visible only to those in southern hemisphere, mostly from the Indian and Pacific oceans and someparts of Australia. However, India will be luckier on August 11, when the last total solar eclipse of the present millennium occurs. The total solar eclipse in August, which will start in the Pacific ocean in the pre-dawn hours can be seen from certain parts of Western, Eastern and Central India, including Srikakulam and Kalingapatnam in Andhra Pradesh, Koraput, Jagdalpur, Shapur, Ballarsha, Vadodara, Akola and Anand besides Tripura.

Incidentally, the total solar eclipse can be seen from the ancient sun temple at Arasavilli near Srikakulam, where the total solar eclipse was also witnessed on February 16, 1980. A penumbral lunar eclipse had occurred on January 31 last and there will be a partial lunar eclipse on July 28 which would not be visible in India. The year 1999, according to astronomers, promises a few astronomical events including the return of Leonid meteor shower sometimes in mid-November. The 1999 showers, as in 1998, are expected to be quite conspicuous, though only from certain places.

Theplanet Mars (Mangal) will also move closer to the Earth on May 1, around which it will rise in the East, exactly after sun set - as Mars will be in retrograde motion in Libra zodiac. Mars will look particularly bright as such a close approach takes place once in a little over two years.

Planet Venus (Sukra) will attain its maximum brightness on September 26 and will be very conspicuous in the sky in the Leonian constellation. A rare occurrence will take place on November 15 in the transit of planet Mercury (Buddha).

Mercury on that day comes exactly in between sun and the Earth. About 13 such transit of Mercury takes place during a century and when they do happen, Mercury can be seen as a black dot gazing across the face of the sun.

However, on November 15, Mercury will be grazing against the edge of the sun - as the conjunction occurs on the cusp of the Libra-Scorpio zodiac and Mercury will be in retrograde motion - and so this will not be such a conspicuous event.

The year 1999 will also see Plutoresuming its position of being the farthest planet in our solar system. For sometime now, Neptune was the farthest planet, because of its elongated orbit.