I was looking toward sunset and noticed a bright object in the sky near the sun. I wasn't sure what it was, so I used Stellarium to check on the identity of the object. It turned out that there were several moons (not of earth, but apparently of Jupiter) in that area, the largest of which by far was the giant moon Dione.
Even in my dream that didn't make much sense to me, and as I drifted back and forth from sleeping-nearly-waking to waking-nearly-sleeping, the following occurred to me in about this order:
- Dione is not really a giant moon.
- It is a moon of Saturn, not Jupiter.
- For such a small object, it is much too far away to be a bright object in our night sky.
- It is probably beyond the diffraction limit of the human eye to resolve Dione from Saturn.
I have no idea what brought this on, but having astronomy in my dreams has been fairly typical since I took an intro astronomy course from the local community college when I was in 10th grade.
At least this time I realized there was something wrong even when I was in the dream. What can be more disturbing is when elements from a dream seem to make sense even after waking.