Video transcript for 'Day and night'
SEYMOUR: Hello, Seymour Science here! As we all know, sometimes itâs day⊠and sometimes itâs night⊠but why do we have day & night? My guest today is here to tell us! Ladies and Gentlemen⊠Rosie!
ROSIE: Thanks Seymour! Many of us live in villages, towns or cities⊠but these are all part of one big place that we call⊠Planet Earth! Earth is lit up by the Sun â
SEYMOUR: which is a star!
ROSIE: Thatâs right. There are billions of other stars similar to the Sun, most are even bigger⊠they're just much further away, so look really small. Our planet spins on an invisible line â called âan axisâ. Half of the Earth is always facing the Sun, meaning it is lit up. The other half is in darkness until the planet turns around. Thatâs why we have day and night!
SEYMOUR: The Sun keeps us warm too, right?
ROSIE: Thatâs right! The Sun is a HUGE ball of gas, MUCH bigger than Earth, and the gas is exploding all the time, so it gets very hot and very bright.
SEYMOUR: But what about the moon?
ROSIE: The moon can look bright tooâ but thatâs because sunlight bounces off it, helping us see at night!
SEYMOUR: Now for the really clever stuff!
ROSIE: The Earth takes one day to completely spin aroundâŠand it takes about a month for the moon to go all the way around the Earth in a circle,
SEYMOUR: we call this an orbit!
ROSIE: and then it take a whole year for both of them to go all the way around the Sun. So this is how we measure days, and months and years.
SEYMOUR: Like I said⊠clever!
MUM: I hope you two arenât making a mess up there!
SEYMOUR: Ooh, got to go!