* Martians, Moon Maidens, Droids, Vulcans and sundry other inhabitants of outer space will don their outfits Saturday night and touch down at the Pension Building at 5th and G Streets NW for the Cosmic Costume Ball and Dance. It's a benefit for D.C. Curators, a nonprofit arts production organization. Prizes will be awarded for the most far-out gear and music of the galaxies will be provided by the most otherworldly of them all, Sun Ra and His Arkestra.

Ra's philosophy: "My music represents the potential future, not the future that is supposed to be. It's about the future that's not supposed to be but is better than the one that is supposed to be. The one that is supposed to be is based upon the fruits of the past and the fruits of the past show what the tree is by what you see today. If the people on this planet don't get something in common quick, they're not going to have anything at all. Our music is a sort of advanced herald of something other than what is, and it is present through myth and what I call cosmo drama."

Countdown will begin at 9 p.m. when the more down to earth Tiny Desk Unit, a local New Wave group, blasts off. For ticket information call 783-0360.