We were treated to a partial lunar eclipse on November 19, 2021. This type of eclipse takes place when the Earth moves between the Sun and the full moon, but they do not precisely form a straight line. If weather conditions are in our favour, half of the moon will appear in the sky with a reddish glow.
Once in a blue moon
Does this well-known phrase have anything to do with the Moon? Well, yes it does. We use it to refer to something happening very rarely and a blue moon is a rare occurrence.
A monthly blue moon is the name given to a second full moon that occurs in a single calendar month and this typically occurs only once every two to three years. In 2020, the Hunter’s Moon on October 31 was a blue moon because it is the second full moon to occur in October.
A seasonal blue moon describes the third of four full moons to occur in an astronomical season.
There’s lots of other moons, too – how many do you know?
Full moon
We all know what these are. They come around every month and light up the sky at night.
New moon
Sometimes known as the invisible phase, as it generally can’t be seen in the sky. It’s when the Sun and Moon are aligned, with the Sun and Earth on opposite sides of the Moon. As a result, the side of the Moon that faces the Earth is left in complete darkness.
Black moon
Most experts agree that this refers to the second new moon in a calendar month, while some use the term to describe the third new moon in a season of four new moons. The last black moon took place on August 19, 2020.
Blood moon
Also known as a total lunar eclipse. It’s when the shadow of Earth casts a reddish glow on the moon, the result of a rare combination of an eclipse with the closest full moon of the year. There was one in the UK in January 2019, with the next one set to be visible over South America, North America and parts of Europe and Africa on May 16, 2022. Space fans in the UK won’t be able to see every phase of this eclipse, but should be able to see it at totality when the Moon appears with a reddish-orange glow.
What is a supermoon?
Ever looked up at the night sky to see a full moon so close you could almost touch it? Well you’ve probably spotted a supermoon.
The impressive sight happens when a full moon is at the point in its orbit that brings it closest to Earth. To us Earth-lings, it appears up to 30 per cent brighter and 14 per cent bigger.