A supermoon is substantially brighter than an ordinary full moon and only happens when a full moon comes closer than usual to Earth.
Stargazers were treated to the phenomenon on Sunday night for the first time since November 14 2016.
Although size of the supermoon was only very slightly larger than any ordinary full moon, seasoned observers would have been able to notice the difference.
The December 2017 supermoon is the first of three full moon supermoons in a row with the next two falling on January 2 and January 31.
The full moon on January 31 will be called a Blue Moon because it is the second of two full moons in one calendar month.
The Blue Moon will pass through the Earth’s shadow to create a total eclipse of the moon during the nighttime hours on January 31.
The last Blue Moon was on July 31 2015 and they usually happen every two to three years so they come around quite often.
The supermoon on Sunday December 3 began to rise at around 4.20pm on Sunday evening and set on Monday morning at 8.15am.
During a supermoon event, the full moon can appear to be up to 14 per cent larger and 30 per cent brighter than on any night throughout the year.
This is because the Moon reaches its perigee – its closest point to Earth in its orbit.
A new moon or full moon coming closer than 362,000 km of Earth in 2017 counts as a supermoon.
The supermoon on Sunday December 3 was 357,987 km close to earth and its lunar perigee distance on Monday December 4 morning was 357, 492km.
This is at great contrast to the smallest and farthest full moon on June 9 2017 was 406,286 km from the Earth which is nearly 50,000km farther away than the December 2017 supermoon.
In January it is expected that the second of the three full moon super moons will be the closest and largest supermoon in the series of three.
The supermoon on January 2 will be 356,846km from earth, so closer than the December 3 supermoon and its lunar perigee will be at 356,565km.
The first three supermoons of 2017 could not be seen because they were new moons. Only fourth supermoon last night was a full moon.