First calender
- orignaly, ancient culters used seasonal cycle of moon, stars and planets to determine.
- egypten people made moon calender
- modern calender is based on our solar system
- there are three tings calender shows.
- day - the time required for Earth to rotate once on its axis
- month - a division of the year that is based on the orbit of the moon around the Earth
- year- the time required for the Earth to orbit once around the sun
constellation
a region of the sky that contains a recognizable star pattern and that is used to describe the location of objects in space
Sky map
shows entire map of sky form given location based on time and date