Sometimes, readers familiar with the full canon of my work will inquire, respectfully, if there exists a level of humor so infantile that I will not lower myself to it. The answer is yes.

For example, a few months ago I wrote about a Dr. Johannes Aas, a pioneer in the field of human poop transplant. Well, shortly afterward I discovered (don't ask me how -- a journalist never reveals his sources) that there is, at the University of Maryland, a professor of electrical engineering named Dr. Andre Tits. I considered writing a column in which I telephoned Dr. Tits and suggested that he and Dr. Aas collaborate on a project. But then I decided that this was too immature, even for me.

In case that doesn't settle the matter, perhaps this will: The other day I received a call from the highly prestigious, world-renowned Smithsonian Institution, wanting to know if I would be interested in covering -- exclusively -- the debut of a science exhibit. Please note that the Smithsonian chose me, and not David Broder.

That is how I recently found myself at the Air and Space Museum's new exhibit of space toilets.

Considering my stature, the Smithsonian arranged for a private showing conducted by Cathleen S. Lewis, curator of the space history division of the museum. The only other specially invited guests were the two dozen 4- and 5-year-olds in Ms. Castro's and Ms. Wells's preschool classes at the Smithsonian. They were celebrating Come-to-School-in-Your-Pajamas Day.

(This is all true. In fact, it was only after I arrived that Smithsonian public affairs specialist Peter Golkin revealed that he had first tried, and failed, to interest KidsPost in the story.)

The exhibit consists of two Russian-made toilets exactly like those that are used in modern space vehicles and space stations. They are housed in fancy glass display cases; possibly the Smithsonian is concerned that if they were left unprotected, a tourist might get confused and use one. This is unlikely, frankly, not only because they are right out in the middle of the main atrium, near the Spirit of St. Louis, but because these toilets look about as comfortable and accommodating for one's naked behind as a propane tank from a backyard barbecue grill.

In fact, that is exactly what they look like -- propane tanks that have been jury-rigged with private-part mutilation devices. Curator Lewis explained that since there is no gravity in space, you don't have to "sit" on these devices so much as you are strapped to them. Gentle vacuum pumps do most of the work.

One of the display toilets is for men, and one is for women. As you might guess if you have ever compared the feminine-hygiene wing of a typical drug store with the male-hygiene bin ("razors"), the women's toilet is a lot more elaborate. I would describe this toilet in detail, except I might faint.

It turns out that space potties have come a long way from the era in which Alan Shepard famously peed in his flight suit. In fact, in the early space missions with less efficient toilets, there were occasional accidents -- and bodily exudates wound up floating around in the weightless cabins for days and days, like cicadas from Hell. These Russian toilets are much better.

One little boy took all of this in and hesitantly asked what I thought was a very good question: "Where do they keep the food?" And Ms. Lewis gave what I thought was a very good answer: "Away from the toilets."

All in all, it was a terrific presentation. My favorite part was learning that, to this day, when astronauts venture outside the spacecraft for any length of time, they wear diapers. This is true; it was revealed exclusively to this reporter. In fact, the curator said, during every moon walk, the astronauts were outfitted in Depends!

I am thinking that this explains a great deal. I always wondered why we had the technology to send a man to the moon and bring him back, but couldn't manage to obtain voice transmissions that sounded clearer than tin cans and a string.

Maybe all that static was intentional. Maybe they didn't want us to hear things too clearly.

Neil Armstrong: "The hatch is open, the stairs are deployed."

NASA: "Houston here. We copy."

Neil Armstrong: "I'm going to step off the Lunar Module now."

NASA: "Roger, Neil. "

Neil Armstrong: "Roger, Houston. That's one small step for man, one giant leak for mankind."

Gene Weingarten's e-mail address is weingarten@washpost.com. Chat with him online Tuesdays at noon at www.washingtonpost.com.