Rare lunar event thrills stargazers

02 February 2018 | General News
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A shadow is cast over different parts of the moon as the eclipse occurs (Photo: Melcolm Lee Jun Jie)

On the night of 31 January, some 150 dedicated stargazers gathered at NUS for talks on the special three-in-one lunar event consisting of an eclipse, a blue moon and a supermoon, followed by viewing of the celestial event through three telescopes set up by the NUS Astronomical Society (NUSAS).

A lunar eclipse occurs when the moon’s orbit brings it to a spot behind the Earth where it is concealed by the Earth’s shadow. Eclipses are regular events, said Dr Cindy Ng, Senior Lecturer at NUS Physics, and an eclipse season takes place every six to seven months. During a lunar eclipse, the moon takes on a reddish hue, when it is also termed as a blood moon.

During a supermoon, the moon appears larger than usual. Each month usually sees one full moon but in certain months, two full moons occur. In such cases, the second moon is known as a blue moon, not so much as a description of its colour but for its rarity. The next blue moon will occur on 31 March, said Dr Ng.

The last time an eclipse, a blue moon and a supermoon occurred concurrently was 152 years ago. Explaining the science behind the rare cosmic event, Dr Ng said, “During a total lunar eclipse, the moon will continue to be illuminated by a small amount of red sunlight refracted onto it by the Earth’s atmosphere. The supermoon occurs because the moon is near a point in its elliptical orbit where its distance to Earth is the closest. The blue moon occurs because Earth’s orbital period around the Sun slightly exceeds twelve times the Moon's orbital periods around Earth. The conjunction of these three events combines physics and our calendar culture.”

The complete lunar eclipse on 31 January began at 7.48pm and ended at 11.11pm, with the total eclipse lasting 76 minutes — from 8.51pm to 10.07pm.

NUSAS arranged for talks and a public viewing in conjunction with the celestial event. The first talk featured NUS Physics alumna Ms Laurentcia Arlany, who shared her experience of travelling to Indonesia in March 2016 to view a total solar eclipse. The second talk saw Year 1 NUS Physics student Wan Si Chen, who is also NUSAS Astronomy Head, sharing interesting facts about eclipses as well as unique characteristics of the lunar eclipse on 31 January.

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An exchange student peering through the lens of the telescope

Year 4 NUS Physics student Clarence Liu, NUSAS President, shared that he had been fascinated about the universe since his secondary school days. “As a first year Physics major, I was eager to learn more about the universe and astronomy. Joining NUSAS gave me the opportunity do so and allowed me to share my joy and knowledge about the sciences with the public, providing me with a platform to let everyone know that science, physics in particular, can be very interesting,” he said.

Nuradila Bte Sadimin, Year 2 NUS Arts and Social Sciences student attended the event with her sister. She found the talks very enriching, saying, “I’ve never really understood how an eclipse happens or that there are three different types of eclipses. It was very meaningful and interesting to learn all these,” she said.

For Year 4 NUS Business students Shaun Low and Terence Tan, it was their first time at a public viewing of an eclipse. They came to observe the eclipse as they felt it would be relevant to one of their modules “Understanding the Universe”.

Attendees at the lunar event included NUS staff and students, as well as the general public. Members of the stargazing fraternity in Singapore were present too, including Mr Grey Tan, NUS alumnus and TinyMOS Founder and CEO; and Mr Melcolm Lee Jun Jie.