So far, when my kids have reached high school level, we wind up signing up for high school classes that are given in the homeschool community around here. Going into a high school level science class with no formal science beforehand would be scary, you would think. However, our mish-mash of exposure to science seems to be enough to provide a solid foundation.
I think it is very easy to unschool science in this day and age. Our approach has been a mixture of interesting read a louds, science kits, and occasional science field trips. Some years we've been lucky enough to participate with other families in co-ops that featured science topics and occasionally we've even participated in the local Catholic homeschool Science Fair.
But the thing that has been the greatest influence is watching TV shows that teach science. All three teens have said that watching the
Magic School Bus shows did the most to prepare them for high school science. Here's the actual
Magic School Bus site.
Of course
Bill Nye is also excellent (we even saw him live once!). These two aforementioned shows were around on TV for my oldest two (now 20 and 18). But my younger three (ages 15, 11 and 9) watched more of Zoom and currently Fetch with Ruff Ruffman. You can check out many of the PBS educational kids shows at
PBSkids.org
My kids don't seem to be headed into careers in science, at this moment (one never knows though!). I know some kids who just eat up the subject and are very self-motivated to learn more. One can picture them designing space ships, for instance. We don't seem to be like that, however, I do think my kids are very well rounded in the subject and can converse about scientific ideas with some fluency.
This little list is only scratching the surface of all the educational science shows out there. I think science in particular lends itself well to learning through the visual medium of TV.