At 6am on Tuesday, Mr Soh Kim Mun secured his camera on a tripod, and fixed his eyes on the sky.
Fifteen minutes later, Mercury finally made its appearance, joining Venus, Saturn, Mars and Jupiter to create an arc of five planets.
The 50-year-old snapped a number of photos before it got too bright to see them.
This has been the engineer's routine for the last month. He is among hundreds here who have ventured out before dawn to catch the phenomenon.
The five planets have been appearing together in the early hours since late last month, a celestial spectacle which is happening for the first time in a decade.
Mr Kwan Jin Peng, 28, stayed overnight twice at the Woodlands Galaxy Community Club - which has a telescope on its roof - to catch the rare sight.
"It just feels really special to be in the midst of something that is happening once in 10 years," said the assistant condominium manager.
For Mr Soh, it is the excitement of seeing Mercury. Due to its closeness to the sun and its speedy orbit around it, it has a reputation of being difficult to spot. "Not only have I been able to see it almost every other day over the last month, I even managed to photograph it with the other planets," he said.
The appearance of the planets has also garnered more interest in the night sky in general, said the Singapore Science Centre.
The number of people attending each of its Friday night stargazing sessions at the centre's observatory has increased by four times to an average of 400 people.
Similarly, the number of people heading to the Woodlands club for its weekly astronomy sessions has doubled to 30.
Tomorrow, however, is believed to be the last day that the planets can be seen clearly with the naked eye. From Sunday, Mercury will appear too close to the horizon, and will be visible only when using telescopes or binoculars, according to astronomy enthusiasts.
Mr Soh, who is also honorary secretary of the Astronomical Society of Singapore, advises going to an open space unobstructed by buildings or trees. "The best time to view them would be between 6.15am and 6.45am," he added.
The planet closest to the horizon will be Mercury, followed by Venus, Saturn, Mars and Jupiter, in an upward arc.
The Science Centre observatory advises using Jupiter and Venus - the brightest of the planets - to locate the others. Mars will be halfway between Jupiter and Venus, and Saturn will be approximately halfway between Venus and Mars.