Gaby rubbed her forehead.

"You haven't heard it all. 1 bounced radar signals off it. They came back telling me Themis was over 1300 kilometers in diameter. Density figures all cockeyed, too, making it less dense than water by quite a bit. 1 thought 1 was getting screwed-up readings because 1 was working at the limits of my equipment. Then 1 got the picture."

"Six bodies or one?" Cirocco asked.

"I can't tell for sure. But everything points to one." "Describe it. What you think you know."

Gaby consulted her printout sheets, but obviously did not need them. The figures were clear in her mind.

"Themis is 1300 klicks across. That makes it Saturn's third

largest moon, about the size of Rhea. It must be flat black all over, except those six points. This is by far the lowest albedo of any body in the solar system, if that interests you. It's also the least dense. There's a strong possibility it's hollow, and a good chance it's not spherical. Possibly disc-shaped, or toroidal, like a donut. Either way, it seems to turn like a plate rolling along its edge, once every hour. That's enough spin so nothing could stay on its surface; the centripetal force would overpower the force of gravity."

"But if it's hollow, and you were on the inside .

Cirocco kept her eyes on Gaby.

"Inside, if it's hollow, it would be equivalent to a force of one- quarter gee. "

Cirocco looked her next question, and Gaby couldn't meet her eyes.

"We're getting closer every day. The seeing can only get better. But I can't promise you when I could he sure about any of this."

Cirocco headed for the door. "I'll have to send what you have."

"But no theories, okay?" Gaby shouted after her. It was the first time Cirocco had seen her less than happy with what she'd seen through a telescope. "At least don't attribute them to me."

"No theories," Cirocco acknowledged. "The facts ought to be plenty."