I used to watch a lot of Mythbusters and Brainiac growing up.
Brainiac for those that don't know:
https://www.youtube.com/watch?v=m55kgyApYrY
More recently there have been quite a lot more science shows on though a lot of them are not aimed at kids. Most could be understood by older kids but more for adults really. Things like Stargazing Live and Brian Cox's Wonders series aren't too hard to follow.
Stargazing Live:
https://www.youtube.com/watch?v=FW7co2v_zGA
Wonders of the Universe:
https://www.youtube.com/watch?v=uQSoaiubuA0
Brainiac for those that don't know:
https://www.youtube.com/watch?v=m55kgyApYrY
More recently there have been quite a lot more science shows on though a lot of them are not aimed at kids. Most could be understood by older kids but more for adults really. Things like Stargazing Live and Brian Cox's Wonders series aren't too hard to follow.
Stargazing Live:
https://www.youtube.com/watch?v=FW7co2v_zGA
Wonders of the Universe:
https://www.youtube.com/watch?v=uQSoaiubuA0