The base of the clock contains a tape recorder, with recordings of Rasmus Sørnes' voice describing the features of the clock. The clock's astronomical part may be driven forwards and backwards at a speed of eight days per minute. The large dial in the middle of the front has a fixed Zodiac and two hands showing the position of the Sun and the Moon on the ecliptic circle. The Sun hand makes one revolution every year, and the Moon hand one revolution every 29.5 day. This dial also shows when and where solar and lunar eclipses occur. The orbit of the Moon has an inclination of 5° with regard to the ecliptic, so solar or lunar eclipses can only occur when the Sun and the Moon are simultaneously located at one of the crossings of the two orbits. These two crossings rotate once in 18.5 years (known as the Saros cycle) and are indicated by the hand with the Ω (omega) sign. Eclipses occur when the three hands overlap, which typically happens two or three times a year; they overlap in nearly exactly the same position every 18.5 years. In the centre of the dial, a spherical slice of the Earth is located. It rotates counter-clockwise once in a sidereal day, and is used to indicate where the eclipse is visible.