Topic 4- Time and Earth, Moon, Sun Cycles

Sidereal and Synodic Days

• A sidereal day is how long it takes the Earth to rotate in relation to the background stars. It takes 23hrs and 56mins
• A synodic day is how long it takes the Earth to rotate in relation to the Sun. It takes 24hrs

Apparent Solar/Mean Solar/Local Mean Time

• Apparent Solar Time is the time shown on a sundial and is based on the position of the Sun
• Mean Solar Time is the time set on watches and clocks
• Local Mean Time is the time at a specific location

Equation of Time

• Equation of Time= Apparent Solar Time - Mean Solar Time
• The elliptical orbit of the Earth means that the EoT varies because Earth speeds up at certain times. The Sun also moves across the sky faster at solstices and slower ar equinoxes, resulting in a varied EoT

Shadow Stick Method

• Place stick on a piece of paper, flat on the ground
• Record the time every 10 mins and mark a cross at the end of the shadow
• Repeat until enough data has…