Wondering

I just checked on the kids. Both of them were still awake. I gave Gillian some kisses. We talked briefly about our elf on the shelf and I said good night. Next I checked on John. I gave him a kiss. He sighed. I asked "What's the matter?" He sighed again and said "Well it's hard to say." So I said "Try. You can tell me anything." He said "I'm just wondering why scientists haven't gone past our solar system." I said "This is what you are worried about?" He said "I'm not worried. I'm just wondering."