The Moon

The easiest thing to observe is our Moon, the view of which changes from night to night as the Sun lights it from different directions. Partial moons (when the moon is somewhere between new and full) give an extremely good view of craters which you can see clearly through binoculars.

The Moon has an elliptical orbit around Earth which means that at perigee (when the moon is closest to the Earth) it is only about 225,623 miles away which results in an especially large looking moon. When it is at its furthest point from the Earth, called apogee or a micro moon, it is 252,088 miles away.

A Blue Moon is when a full moon occurs twice in a calendar month, and the moon may appear larger than usual.

Shooting stars

Shooting stars occur regularly and are a result of the Earth passing through meteor or asteroid debris. Little bits of dust in the debris can enter the Earth’s atmosphere at very high speeds, and appear as streaks of light as they burn up. Sometimes, the Earth passes through more dense areas of debris which causes a meteor shower.

In 2019 we will pass through the Perseids 12-13 August, Orionids 21-22 October, Leonids 17-18 November, Geminids 14-15 December, Ursids 22-23 December, Quadrantids 3-4 January 2020.

Constellations

There are 88 constellations in total, and 47 are observable from the northern hemisphere. As the Earth spins the stars appear to move through the sky from east to west and as the Earth orbits the Sun the view of the stars changes throughout the seasons.

The most easily recognisable constellations are:

• the Plough which is overhead in the sky in spring
• Cygnus ‘the Swan’ is easily seen in summer
• the Square of Pegasus is observable in autumn and in winter
• Orion ‘the Hunter’ is an amazing sight with three stars marking his belt.

Planets and galaxies

There are also the planets, many of which can be seen with the naked eye. Often the most obvious is Venus because, apart from the Sun and Moon, it’s the brightest natural object in the sky.

Mars is also very bright with a reddish tinge to it, and is particularly close to the Earth every two years. Jupiter, the largest planet in the Solar System, shines with a bright white light and with binoculars you can even see some of its moons.

It is also possible to see the Andromeda Galaxy 2.5 million light years away, which is one of the nearest galaxies to our own – the Milky Way.

Northern Lights

The aurora borealis (or northern lights) is a spectacular natural phenomenon which can occasionally be seen in the night sky over Britain. Once seen, it is never forgotten.

It’s a faint visual phenomenon associated with geomagnetic activity, occurring mainly in the high-latitude night sky. Typical auroras occur 100 to 250km above the ground as high speed particles from the solar wind collide with atmospheric gasses at these altitudes. When observed in the northern hemisphere this phenomena is known as the aurora borealis (northern lights), and when viewed in the southern hemisphere it is the aurora australis.

Smartphone apps

There are lots of useful dark skies/astro-apps available, including:

Pocket Universe, Meteor Shower Calendar, Aurora Alert