Monday 26th April to Sunday 2nd May 2021
On the evening of Tuesday 27th April we have a Full Moon. If you are looking towards the southeast from a little before 10 pm, you will see it rise above the horizon.
This particular Full Moon is known as a "Supermoon" because it will appear to be slightly larger than some others. Why is that?
The Moon's orbit around The Earth is slightly elliptical, or in other words, not a perfect circle. This means that sometimes the Moon is a bit further away from us and sometimes closer. The furthest point from the Earth is called "Apogee" when the Moon is 406,000Km from us. The closest point is called "Perigee" and then it is 356,000Km away.
The April Full Moon occurs when the Moon happens to be near Perigee, so it looks a little larger, hence the term "Supermoon".
There is another effect called "Moon Illusion" which is simply a trick that your brain plays on you when viewing an object close to the horizon, making it appear artificially large. If you are watching the Moonrise on 27th, you will also notice this. As the Moon climbs higher in the sky, the affect disappears and you are then looking at the Supermoon itself which is about 7% larger than other Full Moons and around 15% brighter.
Screenshot courtesy of Stellarium
Copyright Adrian Dening and Radio Ninesprings 2021