planet,” he said as he straightened, “would have wiped out all its transmissions. Yes?”
“It would certainly have caused considerable damage. But only on that hemisphere on which it crashed. And then depending on whether it hit the land or the sea. It’s not that big a moon. In one of the larger oceans it might have had no appreciable effect. Tidal waves possibly. On land it may have caused earthquakes. Globally. But even then I can’t see it stopping all transmissions. Besides, you said the transmissions ceased the day before the moon disappeared.”
“But over that distance, a small error in calculation...”
“No. I went to great pains to pinpoint the time exactly. My computations require its position to the second and to the metre.” She tapped buttons on her case, checked date and time with him. “Seven days thirteen hours six minutes twenty three seconds distance?” she said. He concurred. “That makes the moon’s disappearance,” another calculation, “exactly twenty one hours after you lost contact with Happiness. Cause and effect aren’t regressive. And that moon was in full view of our scanners when it disappeared. One second it was there, the next it wasn’t.”
Munred had come to a halt before her, had clasped his hands behind his back and was looking reproachfully down on her,
“Why wasn’t I told of this before?”
“Because,” T’ulla frowned at him, “I, quite by chance, only found out yesterday. I had to verify what I had found before I bothered you with it.”
“Yet you found time to tell Petre. Hardly the behaviour of a professional.”
“My work here isn’t classified. Besides,” Tulla was blushing again, “I saw no need for secrecy.”
“A moon goes missing and you see no need for secrecy?” His facetious tone annoyed Tulla. Her blush deepened,
“I saw that the absence of the moon could have far-reaching consequences. I haven’t computed them all yet, but I felt that I ought to inform you now as you are in charge of this Department. Had I known that Happiness had ceased transmitting I might have looked into that sector before yesterday, have discovered its moon was missing earlier.”
“And when you did discover that its moon was inexplicably missing, didn’t you stop to think they might need emergency services down there?”
“I had no reason to suppose that the moon may have crashed onto the planet. Nor do I still.”
“If it hasn’t crashed onto the planet,” Munred lifted an eyebrow, “where is it?”
“I don’t know.”
“Moons don’t just disappear. Where is it?”
“I don’t know. But what I do know is that at the moment it disappeared it was precisely 386,542 kilometres from the planet’s surface. Nothing I know can exceed the speed of light from a stationary orbit, and that’s what it would have taken for the moon to crash into the planet. And with the moon’s mass such an instant speed, so far as I am aware, is impossible.”
“That still doesn’t mean that it couldn’t have crashed into the planet.”
The man was in a funk, Tulla realised, wanted to pin any possible blame onto her. She was convenient. But Tulla was having none of it. She had been caught up in the petty intrigues and machinations of Service before, knew that, if one did not immediately and forthrightly protest one’s innocence, culpability was rapidly assumed.
“The planet’s rotation is stable,” Tulla said. “That is its orbit at the moment is stable. The moon was not out of orbit prior to its disappearance. And, if the moon had collided with the planet, then the ensuing explosion would have created so much radio noise that my scanners couldn’t have but failed to pick it up. Even if they didn’t, Communication would have been bothered by it. I’ve checked. No explosions. Have you had no other contact with the planet?”
“Not for thirty three days.”
“No ships?”
“No!” he snapped at her, disliking being quizzed. “Not for thirty three