I would try my best not to worry about what/when to expose my child to and just focus on enjoying their early years with them! Let your child lead you - if she's interested in the planets and you have an observatory close by, absolutely take her there and let her experience it if you want to and think she'd like it. You won't be taking away any huge moment of discovery when she's 7 - you'll most likely take her there again and again over the years and instead of a "wow" moment at 7, you'll build a lifetime of memories of an experience you enjoyed together. There will be plenty of other "wow" moments and firsts as your dd gets older - giving her one of them now won't take away anything at all from her future
As parents we tend to get wrapped up in worrying about how to parent and how to do the right thing for our kids that sometimes we forget that just simply focusing on enjoying our kids and having fun with them, meeting them where they are at, gives our kids so much of what they need and want. And it's never easier to do that than when they are young and not yet in school - so get out there and do all those things that you want to do with her, and that she's interested in
Best wishes,
polarbear
