New Delhi, Jan 16 Millions of Hindus bathed in holy rivers and tanks across India after a four-hour celestial spectacle that turned the sun into a 'Ring of Fire', bringing out science enthusiasts to view and record the rare event.

Hundreds of thousands of temples all over the country closed their doors and covered their deities with muslin shrouds during the period when traffic on roads in many cities thinned as people kept indoors.

A partial eclipse was seen in most states, but the 'Ring of Fire' was at the height of its splendour in the southern tip of Tamil Nadu where large crowds erupted in joy and clapped on seeing the rare spectacle.

Even the bustling Maha Kumbh Mela at Haridwar fell relatively silent as bathers completed their morning pre-eclipse rituals by 11.30 a.m. when the sun went into the shadow of the new moon in Uttarakhand.

Temples all over reopened around 4 p.m. after the sun emerged from the shadow of the moon. Hundreds of thousands of bathers flocked to the Ganges and other holy rivers for a "cleansing" bath.

"This (eclispe) is an inauspicious period when the atmospheric pollution increases," seer Radheshyam Maharajji, who had been camping at the banks of the Ganges in Haridwar with seven men from his order, said.

The longest annular solar eclipse of the millennium touched the southern tip of India at 11.06 a.m. The path of the eclipse began in central Africa, crossed the Indian Ocean and then moved to Southeast Asia, ending in southeastern China.

An annular solar eclipse occurs when the sun is covered by the new moon, but its shadow is not big enough to cover the entire disc of the sun. The result is a 'Ring of Fire' around the covered centre of the sun.

Such a phenomenon was last seen in India on November 22, 1965. It will not be seen in the country again before June 21, 2020.

Seer Narayan Giri, who huddled in his saffron robes and a blanket at Haridwar's Har-ki-Pauri, said he spent the morning singing hymns and chanting mantra to redeem the sun god from the shadow of the moon.

In contrast, thousands converged on beaches and at science centres in Kanyakumari, Rameshwaram and Dhanushkodi in Tamil Nadu and watched the 'Ring of Fire'. They used special goggles, telescopes, mirrors or pin-hole reflections following warnings not to view the sun with naked eyes.

The special glasses sold for Rs.5 in the morning. With the progress of the eclipse, the price went up to Rs.40 a pair.

"It is a wonderful and enjoyable experience," I.M. Thaya, an engineering student of the Coimbatore Institute of Technology, said in Kanyakumari. "It is evening at noon," another skygazer said.

The eclipse that started around 11.05 a.m. at Kanyakumari progressed steadily and peaked to reach the annular image at 1.10 p.m.

"Students who measured parameters like intensity of light, temperature, relative humidity and the apparent size of the moon and sun (Thursday) and (Friday) didn't find any major difference between the two readings. It goes to prove nothing changes during an eclipse," said P. Iyamperumal, executive director of the Tamil Nadu Science and Technology Centre.

In order to dispel the long-held belief that eating during eclipse is harmful, some scientists encouraged people to eat.

The Indian Space Research Organisation (ISRO) launched five rockets during the eclipse, carrying instruments to measure its effects in the earth's atmosphere and ionosphere.

A group of enthusiasts on board India's first eclipse cruise ship, Aquamarine, had a longer view in the Maldives.

"The sun looked like a moon in the sky changing shapes, starting from crescent to forming a ring. Wow! I loved it and nothing can be better than this. It was the first time I am watching an eclipse and I never knew it's so beautiful," Rishika Smera, a Class 2 student from Gujarat, said.

Science communication organisation SPACE (Science Popularisation Association of Communicators and Educators) organised the cruise. Its scientists captured images of the 'Ring of Fire' and Bailey's Beads.

The beads are little patches of sun seen in between the undulating surface of the moon. Planetariums, science museums, schools and colleges organised special sessions to let enthusiasts watch and understand the spectacle.