At $4 a ticket, you can afford to take a date to the Minneapolis Planetarium and have things not work out. That's not likely, however, given how much fun this indoor sky-gazing venue can be: It's dark, the ambient music's not half bad, and you watch from a low, cushy bench as the Minneapolis skyline--or at least its 360-degree likeness--is projected on the domed ceiling. Each show chronicles an entire celestial night in about an hour and is geared to the stars' actual positions during the current season. And if that first date turns into lasting romance, head back to the Planetarium early on Valentine's Day for the very popular annual lovers' show--an oh-so-slightly-risqué look at the passions and betrayals of the deities whose namesakes populate the heavens.