‘The point is that since it revolves around the gas giant, it shows one face only to the gas giant, which means that all sides of it face the Neighbor Star in the course of its revolution around the gas giant. And the nature of the orbit is such that, as near as I can tell, the temperature of the world is in the liquid-water stage. And it has an atmosphere. Now I don't have all the subtleties at my fingertips. As I said, I'm not an astronomer. Still, it seems to me that there's a good chance that the satellite is a habitable world.’

Crile Fisher received the news with a wide smile. He said, ‘I'm not surprised. Igor Koropatsky predicted the existence of a habitable planet. He did it without any data on the subject. It was just a matter of deduction.’

‘Did Koropatsky do that? And when did he talk to you, I wonder?’

‘Some time before we left. He reasoned that nothing was likely to have happened to Rotor on the way to the Neighbor Star and, since they didn't return, that they must have found a planet to colonize. And there it is.’

‘And just why did he tell you this, Crile?’

Crile paused and considered, then said, ‘He was interested in making certain that the planet would be explored for possible future use by Earth, when the time came for our old planet to be evacuated.’

‘And why do you suppose he didn't tell me this? Do you have any idea?’

‘I suppose, Tessa,’ said Crile carefully, ‘that he thought I would be the more impressionable of the two of us, more eager to urge that the planet be explored-’

‘Because of your daughter.’

‘He knew of the situation, Tessa.’

‘And why didn't you tell me this?’

‘I wasn't sure there was anything to tell. I felt that I might as well wait and see if Koropatsky was right. Since he was, I am now telling you. The planet must be habitable by his reasoning.’

‘It's a satellite,’ said Wendel, obviously in a temper.

‘A distinction without a difference.’

Wendel said, ‘Look, Crile. No-one seems to be considering my position in all this. Koropatsky fills you full of nonsense in order to have us explore this system and then, presumably, return to Earth with the news. Wu was anxious to have us return with news even before we reached this system. You are anxious for a reunion with your family, regardless of any wider considerations. In all this, there seems to be very little thought given to the fact that I'm the Captain and that I will make the decisions.’

Fisher's voice grew cajoling. ‘Be reasonable, Tessa. What decisions are there to make? What are your choices? You say Koropatsky filled me with nonsense, but he didn't. There's the planet. Or the satellite - if you prefer. It must be explored. Its existence may mean life for Earth. This may be humanity's future home. In fact, some of humanity may be there already.’

‘You be reasonable, Crile. A world can be the right size and temperature and still be uninhabitable for any of a variety of reasons. After all, suppose it has a poisonous atmosphere, or is incredibly volcanic, or has a high level of radioactivity. It has only a red dwarf star to light and warm it, and it is in the immediate neighborhood of a large gas giant. That is not a normal environment for an Earth-type world, and how will such an abnormal environment affect it?’

‘It must still be explored, even if only to find out, certainly, that it is uninhabitable.’

‘For that it may not be necessary to land,’ said Wendel grimly. ‘We'll get closer and judge better. Try, Crile, please try not to outrun the data. I couldn't bear your disappointment.’

Fisher nodded. ‘I'll try- Yet Koropatsky deduced a habitable planet when everyone else told me it was totally impossible. You did, too, Tessa. Over and over. But there it is and it may be habitable. So let me hope while I can. Perhaps the people of Rotor are now on that world, and perhaps my daughter is, too.’

Chao-Li Wu said rather indifferently, ‘The Captain is really furious. The last thing she wanted was to find a planet here - a world, I mean, since she won't allow us to call it a planet - that may be habitable. It means it will have to be explored and we'll just have to go back and report. You know that's not what she wants. This is her one and only chance to be out in deep space. Once this is over, she's through for life. Others will work on superluminal techniques; others will explore space. She'll be retired to an advisory position only. She'll hate it.’

‘How about you, Chao-Li? Would you go out in space again, given a chance?’ Blankowitz asked.

Wu didn't hesitate. ‘I'm not sure that I want to go wandering around in space. I don't have the exploring bug. But you know- Last night, I got the queer notion I might just like to settle down here - if it's habitable. How about you?’

‘Settle down here? Of course not. I don't say I'd like to be Earthbound for ever, but I'd like to be back there for a while, anyway, before striking out again.’

‘I've been thinking about it. This satellite is one in - what? Ten thousand? Who would figure on a habitable world in a red dwarf system? It should be explored. I'm even willing to spend time on it and have someone else go back to Earth and take care of my priority on the gravitational effect. You'd protect my interests, wouldn't you, Merry?’

‘Of course I would, Ghao-Li. And so would Captain Wendel. She has all the data, signed and witnessed.’

‘So there you are. And I think the Captain is wrong to want to explore the Galaxy. She could visit a hundred stars and not see one world as unusual as this one. Why bother with quantity when you've got quality right in hand?’

‘Personally,’ said Blankowitz, ‘I think that what bothers her is Fisher's kid. What if he finds her?’

‘So what? He can take her back to Earth with him. What would that be to the Captain?’

‘There's a wife involved, too, you know.’

‘Do you ever hear him mention her?’

‘That wouldn't mean he-’

Her mouth closed suddenly at the sound outside, and Crile Fisher walked in and nodded at the two.

Blankowitz said quickly, as though to wipe out the previous conversation, ‘Has Henry finished with the spectroscopy?’

Fisher shook his head. ‘I can't tell. The poor fellow is nervous. He's afraid of misinterpreting the thing, I suppose.’

Wu said, ‘Come on. It's the computer that does the interpretation. He can hide behind that.’

‘No, he can't!’ said Blankowitz with fervor. ‘I like that. You theoreticians think that all we observers do is just tend a computer, give it a stroke or two, andsay, “Nicedoggie,” then read off the results. It's not so. What the computer says depends on what you put into it, and I never heard a theoretician face an observation he didn't like without blaming the observer. Never once did I hear him say, “There must be something wrong with the compu-” ’

‘Hold on,’ said Wu. ‘Let's not flood this place with recrimination. Have you ever heard me blaming observers?’

‘If you didn't like Henry's observations-’

‘I'd take them anyway. I don't have any theories about this world.’

‘And that's why you'd take whatever he gives you.’

At this point Henry Jarlow walked in with Tessa Wendel close behind. He looked like a cloud making up its mind to rain.

Wendel said, ‘Very well, Jarlow, we're all here. Now, tell us. What does it look like?’

‘The trouble is,’ said Jarlow, ‘there isn't enough ultraviolet in the light of this weakling star to raise a sunburn on an albino. I have to work with micro-waves and that tells me, at once, that there's water vapor in the world's atmosphere.’

Wendel shrugged it off with an impatient lift of her shoulders. ‘We don't need you to tell us that. A world the size of Earth in a liquid-water range of temperature would surely have water and, therefore, water vapor. That moves it one more notch toward habitability, but only one more thoroughly expected notch.’

‘Oh no,’ said Jarlow uneasily. ‘It's habitable. No question.’

‘Because of the water vapor?’

‘No. I have something better than that.’

‘What?’

Jarlow looked around him at the other four rather grimly, and said, ‘Would you say a world was habitable if, in actual fact, it was inhabited?’

‘Yes, I think I could bring myself to say that,’ said Wu calmly.

‘Are you telling me that you can see that it's inhabited at this distance?’ asked Wendel sharply.

‘Yes, that's exactly what I'm saying, Captain. There's free oxygen in the atmosphere - and in quantity. Can you tell me how that can be without photosynthesis? And can you tell me how you can have photosynthesis without the presence of life? And can you tell me how a planet can be uninhabitable if it has oxygen-producing life on it?’

There was dead silence for a moment, then Wendel said, ‘That is so unlikely, Jarlow. Are you sure you didn't mess up the programming?’

And Blankowitz quietly raised her eyebrows at Wu in an unspoken: ‘See-e-e-e-e!’

Jarlow said stiffly, ‘I have never messed up, as you call it, a programming in my life, but, of course, I'm willing to stand corrected if anyone here feels he is more knowledgeable about atmospheric infrared analysis than I am. It's not my field of expertise, but I did make careful use of Blanc and Nkrumah on the subject.’

Crile Fisher, who had gained considerable self-confidence since the incident involving Wu's bid to return home, did not hesitate to insert his views.

‘Look,’ he said, ‘this will either be confirmed or denied as we get closer, but why don't we assume that Dr Jarlow's analysis is correct and see where that takes us? If there is oxygen in the atmosphere of this world, might we not assume that it's been terraformed?’ All eyes turned to look at him. ‘Terraformed?’ said Jarlow blankly. ‘Yes, terraformed. Why not? You have this world that is suitable for life, except that it has the carbon dioxide and nitrogen atmosphere that worlds without life have - like Mars and Venus - and you dump algae into the ocean and pretty soon it's “Goodbye, carbon dioxide,” and “Hello, oxygen.” Or maybe you do something else. I'm no expert.’

They were still looking at him.

Fisher went on. ‘The reason I'm suggesting this is that I remember there was talk about terraforming on the farms on Rotor. I worked there. There were even some seminars on terraforming that I attended because I felt it might have something to do with the hyper-assistance program. It didn't, but at least I heard about terraforming.’

Finally Jarlow said, ‘In all you heard about terraforming, Fisher, do you by any chance recall anyone saying how long it would take?’