The EPOXI spacecraft's close pass by comet Hartley 2 made jaws drop at NASA. Jets of carbon dioxide spewing from the ends of the comet's nucleus envelop it in a continuous envelope of frozen particles, some up to basketball sized. One investigator compared it to seeing a comet in a snowglobe. Indeed, there are two phenomena going on, as EPOXI deputy principal Jessica Sunshine (am I sexist to say that's a wonderful name for a scientist exploring the universe?) explained: "The carbon dioxide jets blast out water ice from specific locations in the rough areas resulting in a cloud of ice and snow. Underneath the smooth middle area, water ice turns into water vapor that flows through the porous material, with the result that close to the comet in this area we see a lot of water vapor."
COMMENT: The more we explore, the more there is to wonder at. I understand other needs, but I cannot understand the argument that spending one half of one percent of our national budget on probing the universe isn't worth it.