Supermoon to fill the Sunday sky

Calling all amateur stargazers. Keep your eyes glued to the sky on May 6. For, this Buddha Purnima, you can see the biggest and brightest full moon of the year — a phenomenon dubbed the supermoon.

The occurrence is repeated every year when a full moon is closest to the earth (at the perigree).

On Sunday, this will occur at 9am in the country.

According to Arvind Paranjapye, director of the Nehru Planetarium, the earth and the moon on this day will be just 35,6955km away and the moon will be at an angle of 0.5515°.

If you miss out on the morning spectacle, don’t worry. The moon will still look fairly large even in the evening. It will set on the west a few minutes before sunrise on May 6 and will rise again the same evening, about an hour after sunset. Mumbaikars on the west coast can catch the spectacle of the moon setting above the sea at around 5.50am.

In contrast to the supermoon day, November 28 will be the day of the farthest full moon this calendar year. On that day, the moon will be 406,349km away from the earth and it will be at angle of 0.4942°. Therefore, the full moon on May 6 will be about 11% bigger than that on November 28.

"One cannot see the change easily with the naked eye, especially when the two events are so far apart in time. However, one can take a digital image of the moon on May 6 and then take another one of the moon on November 28. The comparison of the apparent sizes will be striking," said Paranjpye.

Orbit shapes size
It was Johannes Kepler, a 17th century astronomer, who discovered that planets do not revolve around the sun in circular orbits. Instead, he found, they move in elliptical orbits. And this isn't limited to planets. All celestial bodies, like moons, revolve in the same way. This is why the distance of the moon from the earth keeps changing. As a result of it, the apparent size of the moon also changes.