Most models of the Moon orbiting the Earth depict its orbit as being circular but we know from Kepler’s Laws that celestial bodies orbit one another in an ellipse rather than a circle. What this means is that sometimes the Moon is closer to the Earth than at other times in its orbit. When this is combined with the Moon being a Full Moon then it’s commonly known as a Supermoon. The last of these occurrences for this year is tonight, the 21 March 2019. At 8:30pm the Moon was 360,242 km away, about the distance it takes light to travel in 1.2 seconds. This is the third Supermoon this year, so basically all of the full Moons this year have been Supermoons.

By comparison the full Moon in August last year was 399,892 km away (1.33 light seconds) and its diameter appeared to be 29.9 arc minutes. Compare that…