Science: What is the Sun and how does it generate energy?

This NASA video describes what the sun is and what it is made out of.  Part of the discussion is about sun spots and solar flares.  They do a great job showing actual video and talk on a younger grade level.

Subject:  Astronomy
Grade Level:  3-12
Length:  3:27

Science: How big is our Earth compared to the sun and other stars?

You have probably all seen the images out there on Google that show how small the Earth is compared to different planets and suns.  This is a video that kind of takes you through that picture.  It is very well done.

Subject:  Astronomy
Grade Level:  k-12
Length:  3:00