Kate Moss is celebrating her 40th birthday (yes, she's turning 40; go ahead and bemoan your lost youth now) the only way one could really expect: by appearing nude on the cover of Playboy. She's already completed the photo shoot, which will run in the January issue, the New York Post reports. In addition to her birthday, the issue will celebrate Playboy's 60th anniversary. It's not her first time posing naked; she's appeared in the buff in fashion shoots and a few ads. Perhaps the weirdest part of the story: Moss has reportedly commissioned a piece from artist Chuck Close based on the Playboy spread. (More Kate Moss stories.)