Scruton Sky at Night – February 2020

On the evening of 8 February we will witness the first of four “supermoons” occurring in 2020. Supermoons are also know as wolf moon, hunters moon or harvest moon but the astronomically correct name is perigee full moon.

The Moon’s orbit is elliptical, meaning its distance from Earth is constantly changing. The two extremes are known as perigee (closest to Earth) and apogee (farthest from Earth) and each occurs once a month. The timing of full moon and lunar perigee or apogee are not in sync but drift in and out of phase over the course of many lunar orbits. Sometimes a full moon occurs close to perigee and the the visual impact of a perigee full moon compared to an apogee full moon is that the Moon is approximately 14% larger and 30% brighter. The second ‘supermoon’ in 2020 will be on 9 March.

Mercury will be at its furthest from the setting sun on 10 February and hence is easier to see. You’ll need good eyesight but look low in the western sky just after sunset. The planet Venus will also be visible to the upper left and will appear much brighter.

Finally, you can catch a glimpse of the International Space Station (ISS) on 3 February at 5.34pm. Look to the south-west where it will first appear; it then travels across to the east-south-east reaching a high elevation of 46º. You need to get the timing right as it will only be visible for about 4 minutes.