The official description of Lot #143 reads as follows:
Amazingly unappetizing but wholly unique freeze-dried "moon food." This particular example, labeled "Beef Pot Roast," measures 2 x 3.5 x 0.75 [inches] and rests within a 5 x 6.5 [inch] sealed pouch to which a nozzle is attached. The label also bears the simple heating instructions: "3 oz. hot water. 5—10 minutes." All of the food was prepared by adding hot or cold water through the nozzle. The food was then squeezed into the mouth through a flat tube stored in the package. Food created for the Apollo missions was preserved through freeze-drying and vacuum-sealing, resulting in a product that kept their nutritional and "taste" qualities.
This taste of space archaeology could be yours for just $521 (at the moment of posting), although be warned: NASA's own biomedical report acknowledges that the "Apollo Food System" was far from perfect, noting that:
1. Inflight food consumption proved inadequate to maintain nutritional balance and body weight.
2. Inflight nausea, anorexia, and undesirable physiological responses experienced by some crewmen were believed to be partly attributable to the foods.
3. Meal preparation and consumption required too much crew time and effort.
4. Water for reconstitution of dehydrated foods was unpalatable initially and contained undesirable amounts of dissolved gases.
5. Functional failures occurred in the rehydratable food packages in the early Apollo flights.
Amazingly, it wasn't until the eighth manned space mission, Apollo 14, that the astronauts returned without experiencing significant weight loss. Today, according to extensive taste-testing by Gizmodo, NASA's Southwestern Corn and Potato Medley, Chicken Teriyaki, and Brownies taste "surprisingly good."
As a bizarre side story, Apollo 14 is also notable for the fact that Stuart Roosa, the mission's Command Module Pilot, took hundreds of seeds from five different tree species (the Loblolly Pine, Sycamore, Sweetgum, Redwood, and Douglas Fir) with him into space. The seeds were germinated upon return to earth, with the resulting "moon trees" planted around the country to celebrate the U.S. Bicentennial in 1976. Most are still alive today—you can find your nearest one here.
Link via @drspacejunk.