New Delhi: A celestial history was made on August 27 when the planet Mars had its closest encounter with the Earth, shining in the sky as a bright yellowish-orange disk to the naked eye.

"It came closest to the Earth at 3.21 pm IST. The distance between the two was 55.8 million kms," Dr N Rathnasree, director of Nehru Planetarium, which made arrangements for public viewing of Mars, said.

However, Mars was not visible during that point due to daytime. Nevertheless, in the evening, when it rose in the horizon, scores of people at Nehru Planetarium and British School watched it through telescopes.

Scientists and amateur astronomers world over have been focussing their telescopes during the past one month, when Mars began its odyssey towards Earth, to catch a glimpse of its polar ice caps and peculiar surface markings. Pictures have been clicked through sensitive telescopes.

Though Mars was closest to the Earth on August 27, closest in last 73,000 years, it is not a one-day phenomenon – Mars has been visible and brightening remarkably in the last one month and will also be visible during September, outshining Jupiter and rivalling Venus. Unlike stars, it does not twinkle.

Astronomers have been able to view the southern polar icecap, which appears as a white patch through telescope. A dark region identified as Syrpis Major, which has numerous craters, and the grandest canyon of the solar system known as Vallis Marinaris have also been viewed.

"It appeared like a jewel shining in sky," Amitabh Pandey from the Science Popularisation Association of Communicators and Educators (SPACE) said. "We have been able to view Syrpis Major Planetia as a V- shaped dark colour patch. It was one of the first features viewed by the famous astronomer Cassini through telescope."

Pandey said in earlier attempts, he watched Southern polar ice cap and Vallis Marinaris, which appeared as a dark streak. However, the ice cap was now shrunk in view as that side of Mars is facing the sun, leading to evaporation of carbon dioxide ice. Mars is also known for its grand mountain, three times higher than Mt Everest, called Oklympus Mons.

The planet would not get closer than this to Earth until year 2287, when it would be 70,000 kms closer.

It is currently the sole naked eye planet visible in the direction opposite to the Sun. All other planets, including the brightest Venus, are rather close to the Sun, thus invisible to the naked eye. The area is also relatively free of bright stars.

Mars and Earth come closer to each other once every two years in a phenomenon called Opposition. But not every Opposition is the same," Rathnasree said adding in an Opposition, the Earth, the planet and the Sun fall in a straight line.

PTI