They ended up going to the planetarium that Saturday. Henry insisted that he was too big for the stroller by stoutly saying "I wanna walk!" so he ended up happily situated between his parents, holding both of their hands.
After seeing Bennett's parents do it a while back he was fond of being swung by his arms while walking and often insisted upon it. Hazel was weak to his demands and Will was weak to hers so they both counted to three and swung him in the air multiple times as they made their way through the parking lot.
Henry giggled madly and repeated "again, again!" right up until they made it to the ticket counter. He looked around inside at all the models of the planets hanging from the ceiling in the lobby with a sense of awe, pointing each one out by name.
"Look, Daddy, Saturn!" or "Mummy, it's Mars!" could be heard as he rushed around trying to get a better look at them.