15th May 1618 Johannes Kepler discovers the mathematical rule governing the orbits of our solar system’s planets. The image left is form a painting by an unknown artist in 1610. Known as Kepler’s Third Law of Planetary Motion it states …. “The square of the orbital period of a planet is proportional to the cube of the semi-major axis of its orbit” …. or to put it more simply, if you square the 'year' of each planet and divide it by the cube of its distance to the Sun,

The Sun is an important area of research. The European Space Agency launched the Solar Orbiter Mission which is returning images of the Earth's closest star and in September last year this stunning video of the Missions first images was assembled. But observations from our planet by astronomers have been important in providing long baseline data over centuries using a variety of techniques. The image right is a drawing of sunspots by Galileo Galilei: History and Demonstra

This Month . . . . Twilight. There are three types of twilight, and they are all defined by the angle of the Sun. Civil twilight: Occurs when the Sun is six degrees below the horizon. It ends at sunrise in the morning or follows sunset in the evening. There is enough light to distinguish physical objects without artificial lighting. Only the brightest stars and planets, like Venus and Jupiter, can be seen with the naked eye. Nautical twilight: Occurs when the Sun is between s