“Each month, the Moon comes closest to Earth at perigee and swings farthest away at apogee.”
According to astronomer Richard Nolle, a Supermoon only appears when the Moon is within 90 percent of its perigee relative to its closest perigee in a given year.
By this definition, the astronomer only considers the March and April Full Moons this year to be super.
Astronomer Fred Espenak takes a different approach and believes the Full Moons in February, March, April and May will be super.
He said: “Surprisingly, there are frequently four or more Supermoons – out of a possible 12 to 13 Full Moons – each year.
source: express.co.uk