Channel #18: “Blue lakes means that whatever makes the seas red doesn’t operate at high altitudes—”
Channel #5: “That’s garbage, there can’t be a height effect with that kind of gentle gradient, it just won’t support a—”
Channel #18: “Okay, then it takes time to make the chemistry go, so by the time the rainfall has run down to the lowlands something’s—”
Channel #29: “—he’d got that wrong twice, Christ, so I kinda shrug and mutter, nothing wrong with having nothing to say, sure but try not to say it out loud, and the sonabitch went straight to Gulvinch about it then—”
Channel #20: “— intensifahs all ’at till the domed strata—yeah, ’at’s the ticket—they can’t support the shear stress an’ they rupture, all back unner that ice on the other hemisphere too I bet, uh-huh, an’ you get lotsa cyclin’ in the surface materials, rip open the seams ever’ couple hunnert thousan’ years, think what that does to the rep rate with the atmosphere when you bake out that iron exposed fresh ever’ time—”
Channel #5: “Look, that’s one thing we do know: look at that spectrum, it would be a reducing atmosphere with all that iron, for sure, except the oxygen levels get pumped up, but even so it’s only around the two percent level, two percent 02, you can see that right here, look, it’s just a spike out on that wing, the line strengths are wrong, nothing like Earth, but I bet it’s the same damn process, the same way our air converted over from reducing billions of years back, trouble is it’s not much O2 is it? Not damn much if you want to breathe down there.”
Channel #6: “It’s both forms, open your eyes, lay that one over the other and it jumps right out at you—”
Channel #3: “Ah, ferrous and ferric. Both. So there’s a lot of oxygen down there, as much as Earth, but it’s tied up in the iron.”
Channel #29: “—nothing I could say would—”
Channel #20: “—so see this fits what the backscatter boys say, the faultin’ rips up the goddamn turf so much the iron gets reprocessed alla time an’ the air, it jess can’t hold onto its oxygen, the water jess runs off ever’ time it rains an’ the sea, it’s jess this solution a ferrous crap, ’at’s where th’ O2 is, man I tell you—”
Channel #56: “That jocko over in P4 has got some crazy idea, lissen to him, thinks it’s all iron, but give a gear at this, in the big spot there, see that big volcano, that’s sulfur for sure, big spouts of it coming out reg’lar as Maybelle, sulfur volcanoes smack in the middle of the Eye, and if that doesn’t tie up a lot of oxy, with those winds, I mean, we measured gusting velocity from the action-frame zats and they’ll mix the whole damn atmosphere in two, maybe three years, so you’ve got sulfur oxide all down there, that’s what the Eye is, that’s not sand dunes, not silicon dioxide, it’s sulfur dioxide—”
The picture sharpened as computers edited out random refractions from the clotted air below. Isis swam nearer.
Yellow. A dry, ancient yellow. Smooth sands of it, shimmering, flecked with tan ridges of weathered rock. The Eye peered at Ra, which hung forever directly overhead. Out from the hard-baked center, the subsolar point, swept winds heavy with pungent acid dust. Dunes marched before the winds in ranks a hundred kilometers long. Slowly they swerved as the air currents circled, following a trade-wind pattern, returning to the blistered pupil of the Eye, surging in a timeless cycle.
The Eye’s edge faded into russet, then into brown. A hint of moisture; scrub desert. Rumpled red hills built into a concentric ring of mountains: socket of the Eye. Snow dotted the peaks white. High valleys cupped cold air over the steel-blue sheen of lakes.
The steady rub of the Eye winds had smoothed the land. The breeze stirred up pink dust, thick sheets that poured over the high mountain slopes and down, out-ward from the Eye, filling the valleys with a roiling haze. Only in the shifting spots where neither clods nor dust lay upon the land could the distant telescopes see the dry plains and carved valleys of Isis.
The single, immense, concentric mountain range was intricate and fault cut. Muddy rivers ran down the broad slopes, away from the Eye, toward the planet-circling sea. Farther from the Eye, scrub desert yielded to matted vegetation. Brown grass. Something like trees. Shades of brown, of pinks and grays and pale orange.
A fine dust hung in the lower air, fuzzing optical images, stealing definition. Only in the infrared was the seeing good enough to distinguish objects in the five-meter scale range. Large flora. Bands of vegetation crowding the snaking rivers.
The IR peered down and picked out detail. Dark beds of plant life in the sea. Grasslands. And then, movement.
“ReppleDex, this is Command. You guys got that system up yet, or do we kick ass out there?”
We got good definition in the radio right now, Ted. Give it a—
“I’m looking at it, Alex. What we want is the interferometry—”
“They’re point sources, aren’t they?”
“Nigel, this is Ted. Get off the comm lines.”
“I’m a consultant, remember? Just eavesdropping, anyway.”
“Okay, so long as you don’t get in the way of—Hey, RD, when can we have—”
He’s right, Ted, we still can’t resolve the sources. They’re damned small. Any really big dish we could see at a range of one AU, so I’d think by now we shoulda picked up—
“Okay, okay, that’s interesting. But—”
—and the reason we’ve never been able to make sense out of the signals, we’ve got that figured now—
“Oh? What?”
There are these point sources, maybe a million of ’em, but they’re not transmitting together. I mean, they’re not in synch phase-locked. All the sources are trying to send the same stuff but they’re all a little behind or a little ahead of each other, so it gets muddied up.
“Beats the hell out of me, why somebody’d pick that way for interstellar communication.”
“Alex, what is the length over which the signals are correlated?”
“Nigel, I asked you—”
“Leave off a bit, eh? Alex?”
Well, lemme run this here … Yeah, the spatial correlation length is about thirty klicks, maybe a little more.
“How does it fit in with the topography?”
Here, plug me in on that multichannel, Ted, and—Yeah, there it is.
“Does it follow the valley profiles?”
Uh, yeah. Sort of. Sources are strung out along the valleys. Not many in the mountains.
“The valleys are where the best living is. The water. Over to you, Ted.”
“Many thanks, Nigel. It is nice to get a word in now and then. Let me get this straight, Alex. If you scan the interferometer across the valley, you find the signal is coherent. All the point sources are sending together?”
Correct.
“But if you go to the next valley, the sources are sending something slightly ahead or behind of the first valley?”
Yeah. That’s what’s so goddamn strange. The bit rate is still low, too. And the sources, they’re not steady.
“How so?”
Well, every few minutes one of ’em will drop out. A new one comes in every now and then, too, so the number is about constant.