JANUARY 22, 2018
THEY SPENT ANOTHER DAY IN HARD, EARNEST LABOR. RAOUL AND VIKTOR were refitting every possible seal, testing every valve, examining electrical interfaces, endlessly checking, checking, checking.
There was plenty of gofer work for Julia and Marc. He, however, was more than willing to take some of her chores. That freed some of the day for Julia’s greenhouse experiments. Just why Marc was so willing she did not question, though she suspected that his anxiety over the ERV exceeded his interest in the vent mat. Maybe he was trying to help everyone, bridging the growing gap in their interests with his work.
She forgot all that as soon as she stepped inside the greenhouse.
The mat samples were indeed growing. In the mist chamber the pieces had expanded and merged, nearly covering the available floor space. Where they touched they blended seamlessly: this was a surprise that hinted at their complexity. Individual bacterial cultures would maintain a perimeter, whereas cultured tissue from higher plants and animals would be expected to blend together. In a few places there was a hint of more complex structures.
She had enough material to start some more sophisticated biochemical tests. She gingerly cut off a piece of the mat, bracing for some kind of reaction. But nothing happened.
She froze, then thin-sectioned tiny pieces of mat for biochemical staining and microscopic examination. Under the microscope the colors showed that the basic constituents of life—proteins, lipids, carbohydrates, nucleic acids—were the same here, or at least close enough to respond to the same simple chemical tests.
“All right!”
This was already a big step. Although the biologists had been betting that Mars life would be carbon-based, no one had known for sure what she would find. Some had speculated it could be silicon-based—even some kind of self-assembling mineral life. But so far matters were a lot less strange.
Doing all the tests carefully took a lot of time, and she was more than ready to quit when she saw the dune buggy with the guys trundle slowly by.
The next day was equal parts tedium and excitement: careful, slow work rewarded by glimpses of the fast-growing and ever more complex biofilm. On her stretch breaks she stared through the plastic walls of the mist chamber and thought, I’m looking at aliens.
The words brought no fear, just wonder.
She was ready for the next step, to find out how close it was genetically to Earth life.
She used standard lab techniques and extracted what seemed to be DNA from the microbes. So how similar was it to Earthly DNA?
DNA spells out the amino acids, which then construct the cellular proteins—both the structural brickwork and the busy enzymes that do the cell’s business. If Martian DNA spelled in the same language as on Earth, it would mean unequivocally a common origin for life.
Time for biotech on a stick.
She prepared to run some comparative tests using the DNA of terran microbes she’d brought along. Basically, you unzip the double-stranded DNA helix by heating, then mix the soup of single strands with single strands of a different DNA. When the mixture is cooled down again, strands that are similar enough pair up.
Ten years earlier she’d have had to run through a series of tricky lab protocols. She’d done it often enough in grad school, but it would’ve been difficult under greenhouse conditions.
Luckily, development of elegant new chip-based technology and new theory had allowed her to bring to Mars a library of what was hoped to be representative genes from Earth organisms. These were mostly from microbes, and heavily biased toward primitive anaerobes, the archaebacteria.
Craig Venter, an Axelrod-type biotech entrepreneur, had sequenced some of Earth’s smallest microbes and found that they shared about 300 genes in common. He argued that this was the minimum genome necessary for life. This notion was somewhat controversial, but had enough promise that Julia’s gene library included Venter’s selection.
The new technology was kin to simple home-use pregnancy and glucose test sticks. Unique sequences from microbial genes were attached to tiny glass chips in a rectangular array. Each was tagged with a fluorescent dye.
If the Marsmat DNA recognized a similar sequence by pairing with it, the dye would fluoresce. Picked up by a small charge-coupled detector, the results were displayed on Julia’s electronic slate. The similar sequence “hits” would light up in the array, like a bingo card. The number of hits was the number of genes the Marsmat had in common with Earthly microbes.
That afternoon, her first test—using Venter’s 300 “essential” genes—came up with seventy-nine hits.
Seventy-nine…what did that mean?
It was an equivocal answer. It was enough pairing to indicate that life on both planets used the same four-letter alphabet and probably the same language.
She longed to talk to Chen, or her old friend Joe Miller in Texas, or her dad. To work alone on a discovery of this magnitude was crazy. She could miss something important—would certainly miss something.
The automatic lights came on, startling her. It was dusk, and she’d have to hurry to beat the plummeting temperatures back to the hab.
The rest would have to wait.
As she suited up, she felt like Dr. Frankenstein working away in splendid isolation in his drafty old castle. But even he had Igor to talk to.
As she came out of her shower at the end of the day, Viktor was out in the public area, talking to the big screen. She paused. The screen view was of ruddy hills catching the first slanting beams of sunset. In the foreground stood Lee Chen in a brilliant sky blue hard suit.
“—found some interesting outcroppings on the eastern slope. We went where you didn’t—your tracks are still here. Our aim is to gather a wider range of samples, building upon what you have learned already.” Chen walked slowly to the left, opening up the view, and the camera panned after him. Julia could see the shadow of their rover.
“They are using our relay satellite,” Viktor whispered to her.
“Some kind of deal with Axelrod?”
“Or NASA. I am not sure of rights.”
“—and with Gerda I am preparing to take cores in areas similar to those of Marc and Julia. My goal here is to verify independently and yet in different terrain the stratigraphic density and dating data you acquired.”
“Good idea,” Julia said, leaning into their camera’s field of view. “We’ve been wondering why we couldn’t hail you.”
Chen nodded. “A relay problem. I hope it is solved now.”
“You have been out, all three, for three days?” she asked.
“Yes, testing our equipment. Our comm bands are not yours. Connection through satellite is best, we find.”
“Cold enough for you?” Viktor asked mildly.
