The moon is set to get a lot bigger and brighter than average this weekend as it officially becomes full on Saturday (May 5) at 11:35 pm EDT.

And since this month’s full moon coincides with the moon’s perigee — its closest approach to Earth — it will also be the year’s biggest.

The moon will swing in 221,802 miles (356,955 kilometres) from our planet, offering skywatchers a spectacular view of an extra-big, extra-bright moon, nicknamed a supermoon, the Discovery News reported.

According to meteorologist Joe Rao, besides moon’s perigee coinciding with full moon this month, this perigee will be the nearest to Earth of any this year, as the distance of the moon’s close approach differs by about 3 percent. 

This occurs because the moon’s orbit is not perfectly circular.

This month’s full moon is due to be nearly 16 percent brighter than average. Conversely, later this year on November 28, the full moon will coincide with apogee, the moon’s farthest approach, offering a especially small and dim full moon.

Though the rare appearance of this month’s full moon may be surprising to some, there’s no reason for alarm, scientists cautioned. 

The slight distance variation is not enough to cause any earthquakes or extreme tidal effects, experts asserted.

However, the normal tides around the world will be mostly high and low. At perigee, the moon will exert about 42% more tidal force than it will during its next apogee two weeks later, Rao added.

The last supermoon appeared in March 2011.