Tonight and tomorrow night my friends in Circus Contraption and the Aerialistas are performing in the Seattle Center House as part of Winterfest (and it’s free). At 7:00 p.m. both nights, a dozen wood nymphs, snow sprites, and frost fairies will spin, dance, and drop from the heights of the Center House ceiling in a full-length aerial ballet, accompanied by live music from the Circus Contraption Band. Also, the holiday ice rink in the Fisher Pavillion is open until 8 p.m. tonight and 11 p.m. on Friday ($7).