- The Rock Hall Ball celebrates Halloween.
Your first stop at the Rock Hall Ball is the judges' table, just inside the front door. Each costume is rated, and prizes are later awarded in each of five categories: Best Rock Star, Best Group Effort, Best Couple, Scariest, and Most Original. Winners are awarded prizes ranging from gift certificates and Gibson guitars to an overnight stay at the Ritz-Carlton and a $5,000 studio-recording package. "It's crazy," says the Rock Hall's Todd Mesek. "A lot of people will do rock-star themes because of the venue." The Aphrodesiatics and DJ Packy Malley will keep the crowd grinding, and astrologers, tarot-card readers, and psychics will bring the future to the present. It happens from 8 p.m. to 1 a.m. Saturday at the Rock and Roll Hall of Fame and Museum, 1 Key Plaza. Admission is $50 (including hors d'oeuvres and two drinks); call 216-781-7625. -- Cris Glaser
In "Higher Than Everest: An Adventurer's Guide to the Solar System," astronomer Paul Hodge looks at the literal high points found in our solar system. There's Mars's Mount Olympus (which is higher than Earth's Mount Everest) and a gorge that's more impressive than the Grand Canyon, the moon's Alpine Valley, and other cool space things that can be seen only through super-powered telescopes. Hodge fills in the details at 7:30 p.m. Friday at the Cleveland Museum of Natural History (1 Wade Oval Drive). Museum admission is $7 and $8. Call 216-231-1177 for more information. -- Michael Gallucci
The very mention of Hairotica conjures images of phallic bouffants. "It just happens to be a hair show," says Marian Jacobs, the event's creator and owner of Oasis Salon Solutions. "But I don't think anybody is going to notice that it originated with a hair company." That's because a DJ will be spinning '70s tunes, models will be showing off new and retro hair fashions, and hors d'oeuvres and cocktails will be plentiful. The crowning moment is a competition between salons to see how creative their stylists can get with cuts, colors, and costumes. "They're going to use feathers, costumes, and fake hair," says Jacobs. Hairotica happens from 5 to 11 p.m. Sunday at the Velvet Dog (1280 West Sixth Street). Admission is $35. For more information, call 877-226-2747. -- Diane Sofranec