“All right, enough of this. I want to know how you find Venus.”

I went to the local hardware store and bought a bunch of two-by-fours, three-quarter-inch plywood, power tools, and other stuff I’d need. Steve the army guy helped me carry a lot of it in. Jerk army guy did nothing.

Over the next six hours, I built a lightproof closet with a shelf in it. It was just big enough for me to get in and out. I set the microscope on the shelf. The “door” was a plywood panel that I could remove with screws.

I ran power and video lines into the closet through a little hole that I plugged up with putty to make sure no light could get in through there either. I set my IR camera up on the microscope and sealed up the closet.

Out in the lab, the monitor showed the infrared light the camera saw. It was basically a frequency shift. Very low bands of IR would show up as red. Higher-energy bands would be orange, yellow, and so on up the rainbow. I could see the Astrophage cells as little red blobs, which was expected. At their constant temperature of 96.415 degrees Celsius they would naturally emit an IR wavelength of 7.8 microns or so—the low end of what I’d set the camera to look for. It was good confirmation that the setup was working.

But I didn’t care about that dark-red color. I wanted to see a bright-yellow flash. That would be the Petrova frequency that Astrophage spit out to move around. If any of my Astrophages moved even the tiniest amount, I’d see a very obvious yellow flash.

But it never came. Nothing happened. Nothing at all. Usually, I’d see a jerky motion from at least one of them every few seconds. But now there was nothing.

“So,” I said. “You little brats have settled down, eh?”

Light. Whatever their navigation system was, it was based on light. I suspected that would be the case. What else could you use in space? There’s no sound. No smell. It would have to be light, gravity, or electromagnetism. And light’s the easiest of those three to detect. At least, as far as evolution is concerned.

For my next experiment, I taped a little white LED and a watch battery together. Of course, I wired it backward at first and the LED didn’t light up. That’s pretty much a rule in electronics: You never get diodes right on the first try. Anyway, I rewired it correctly and the LED lit up. I taped the whole contraption to the inside wall of the closet. I made sure to position it so the Astrophage on the sample slide would have a direct line of sight on it. Then I sealed everything up again.

Now, from the Astrophage’s point of view, there was a lot of black nothingness and one shining spot of white. That’s kind of what Venus might look like if you were out in space and looking directly away from the sun.