“Okay.”

“I put a few dots under a vacuum and ran a spectrograph. Just a simple test to see if they emit light. And they do, of course. They give off infrared light at the 25.984 micron wavelength. That’s the Petrova frequency—the light that makes the Petrova line. I expected that. But then I noticed they only emit light when they’re moving. And boy, do they emit a lot of it. I mean, not a lot from our point of view, but for a tiny single-celled organism it’s a ton.”

“And how is that relevant?”

“I did some back-of-the napkin math. And I’m pretty sure that light is how they move around.”

Stratt raised an eyebrow. “I don’t follow.”

“Believe it or not, light has momentum,” I said. “It exerts a force. If you were out in space and you turned on a flashlight, you’d get a teeny, tiny amount of thrust from it.”

“I didn’t know that.”

“Now you do. And a teeny-tiny thrust on a teeny-tiny mass can be an effective form of propulsion. I measured the dots’ average mass at about twenty picograms. That took a long time, by the way, but that lab equipment is awesome. Anyway, the movement I see is consistent with the momentum of the emitted light.”

She set her tablet down. I had, apparently, accomplished the rare feat of getting her undivided attention. “Is that something that happens in nature?”

I shook my head. “No way. Nothing in nature has that kind of energy storage. You don’t understand how much energy these dots are emitting. It’s like… getting to the scales of mass conversion. E = mc² kind of stuff. These tiny dots have more energy stored up in them than remotely makes sense.”

“Well,” she said. “They did just come from the sun. And the sun is losing energy.”

“Yeah. That’s why I think it’s a life-form,” I said. “It consumes energy, stores it in some way we don’t understand, then uses it for propulsion. That’s not a simple physical or chemical process. That’s complex and directed. Something that must have evolved.”

“So the Petrova line is… tiny little rocket flares?”

“Probably. And I bet we’re only seeing a small percentage of the total light coming off that area. They use it to propel themselves to Venus or to the sun. Or both. I don’t know. Point is, the light will go away from their direction of travel. Earth isn’t in that line, so we only see the light that reflects off nearby space dust.”

“Why do they go to Venus?” she asked. “And how do they reproduce?”

“Good questions. Ones I don’t have answers for. But if they’re single-celled stimulus/response organisms, they probably reproduce through mitosis.” I paused. “That’s when the cell splits in half to become two new cells—”

“Yes, I know that much, thank you.” She looked to the ceiling. “People always assumed our first contact with alien life—if any existed—would be little green men in UFOs. We never considered the idea of a simple, unintelligent species.”