It is amazing how much my 12 year old daughter knows about space. She told me what a Gamma Ray Blast is. Where could she have learned that? And are your children interested in space and that stuff?
There's a ton of info on astronomy online (and it's a burst, not a blast). But see if you can encourage it - maybe get involved with a local astronomy club or something. That's what I did at that age, and now I'm getting my PhD in the field.
When my younger brother was 6 he watched nothing but the weather chanel. While his friends knew all about Pokemon and Power Ranger, he knew about jet stream patters, barometric readings, and could tell you in detail how huricanes and tornados are formed.