Ophelia's brow lightly furrows, with a delicate frown. Her father forbade her from spending her chilled nights alone under the stars -- for her health, he said, and if she protested but my brother he would interrupt at once with you are not your brother. But Ophelia would pore in private over star maps and mathematical models, recent re-orderings of the heavens with the sun at the center, or the earth and sun circling in tandem. If Pluto is a planet, it's a planet farther than any map has gone. "Named," she asks, "for the Roman god of the underworld?"