Plankton frozen in the glacier? Corky Marlinson sounded not at all sold on Rachels explanation. Not to rain on your parade, but usually when things freeze they die. These little buggers were flashing us, remember?
Actually, Tolland said, giving Rachel an impressed look, she may have a point. There are a number of species that enter suspended animation when their environment requires it. I did an episode on that phenomenon once.
Rachel nodded. You showed northern pike that got frozen in lakes and had to wait until the thaw to swim away. You also talked about micro‑organisms called waterbears that became totally dehydrated in the desert, remained that way for decades, and then reinflated when rains returned.
Tolland chuckled. So you really do watch my show?
Rachel gave a slightly embarrassed shrug.
Whats your point, Ms. Sexton? Norah demanded.
Her point, Tolland said, which should have dawned on me earlier, is that one of the species I mentioned on that program was a kind of plankton that gets frozen in the polar ice cap every winter, hibernates inside the ice, and then swims away every summer when the ice cap thins. Tolland paused. Granted the species I featured on the show was not the bioluminescent species we saw here, but maybe the same thing happened.
Frozen plankton, Rachel continued, excited to have Michael Tolland so enthusiastic about her idea, could explain everything were seeing here. At some point in the past, fissures could have opened in this glacier, filled with plankton‑rich saltwater, and then refroze. What if there were frozen pockets of saltwater in this glacier? Frozen saltwater containing frozen plankton? Imagine if while you were raising the heated meteorite through the ice, it passed through a frozen saltwater pocket. The saltwater ice would have melted, releasing the plankton from hibernation, and giving us a small percentage of salt mixed in the freshwater.
Oh, for the love of God! Norah exclaimed with a hostile groan. Suddenly everyones a glaciologist!
Corky also looked skeptical. But wouldnt PODS have spotted any brine ice pockets when it did its density scans? After all, brine ice and freshwater ice have different densities.
Barely different, Rachel said.
Four percent is a substantial difference, Norah challenged.
Yes, in a lab, Rachel replied. But PODS takes its measurements from 120 miles up in space. Its computers were designed to differentiate between the obvious‑ice and slush, granite and limestone. She turned to the administrator. Am I right to assume that when PODS measures densities from space, it probably lacks the resolution to distinguish brine ice from fresh ice?
The administrator nodded. Correct. A four percent differential is below PODSs tolerance threshold. The satellite would see brine ice and fresh ice as identical.
Tolland now looked intrigued. This would also explain the static water level in the shaft. He looked at Norah. You said the plankton species you saw in the extraction shaft was called‑
G. polyhedra, Norah declared. And now youre wondering if G. polyhedra is capable of hibernating inside the ice? Youll be pleased to know the answer is yes. Absolutely. G. polyhedra is found in droves around ice shelves, it bioluminesces, and it can hibernate inside the ice. Any other questions?
Everyone exchanged looks. From Norahs tone, there was obviously some sort of but"‑and yet it seemed she had just confirmed Rachels theory.
So, Tolland ventured, youre saying its possible, right? This theory makes sense?
Sure, Norah said, if youre totally retarded.
Rachel glared. I beg your pardon?
Norah Mangor locked stares with Rachel. I imagine in your business, a little bit of knowledge is a dangerous thing? Well, trust me when I tell you that the same holds true for glaciology. Norahs eyes shifted now, looking at each of the four people around her. Let me clarify this for everyone once and for all. The frozen brine pockets that Ms. Sexton has proposed do occur. They are what glaciologists call interstices. Interstices, however, form not as pockets of saltwater but rather as highly branched networks of brine ice whose tendrils are as wide as a human hair. That meteorite would have had to pass through one hell of a dense series of interstices to release enough saltwater to create a three percent mixture in a pool that deep.
Ekstrom scowled. So is it possible or not?
Not on your life, Norah said flatly. Totally impossible. I would have hit pockets of brine ice in my core samples.
Core samples are drilled essentially in random spots, right? Rachel asked. Is there any chance the cores placements, simply by bad luck, could have missed a pocket of sea ice?
I drilled directly down over the meteorite. Then I drilled multiple cores only a few yards on either side. You cant get any closer.
The point is moot, Norah said. Brine interstices occur only in seasonal ice‑ice that forms and melts every season. The Milne Ice Shelf is fast ice‑ice that forms in the mountains and holds fast until it migrates to the calving zone and falls into the sea. As convenient as frozen plankton would be for explaining this mysterious little phenomenon, I can guarantee there are no hidden networks of frozen plankton in this glacier.
The group fell silent again.
Despite the stark rebuttal of the frozen plankton theory, Rachels systematic analysis of the data refused to accept the rejection. Instinctively, Rachel knew that the presence of frozen plankton in the glacier beneath them was the simplest solution to the riddle. The Law of Parsimony, she thought. Her NRO instructors had driven it into her subconscious. When multiple explanations exist, the simplest is usually correct.
Norah Mangor obviously had a lot to lose if her ice‑core data was wrong, and Rachel wondered if maybe Norah had seen the plankton, realized shed made a mistake in claiming the glacier was solid, and was now simply trying to cover her tracks.
All I know, Rachel said, is that I just briefed the entire White House staff and told them this meteorite was discovered in a pristine matrix of ice and had been sealed there, untouched by outside influence since 1716, when it broke off of a famous meteorite called the Jungersol. This fact now appears to be in some question.
The NASA administrator was silent, his expression grave.
Tolland cleared his throat. I have to agree with Rachel. There was saltwater and plankton in the pool. No matter what the explanation is, that shaft is obviously not a closed environment. We cant say it is.
Corky was looking uncomfortable. Um, folks, not to sound like the astrophysicist here, but in my field when we make mistakes, were usually off by billions of years. Is this little plankton/saltwater mix‑up really all that important? I mean, the perfection of the ice surrounding the meteorite in no way affects the meteorite itself, right? We still have the fossils. Nobody is questioning their authenticity. If it turns out weve made a mistake with the ice‑core data, nobody will really care. All theyll care about is that we found proof of life on another planet.
Im sorry, Dr. Marlinson, Rachel said, as someone who analyzes data for a living, I have to disagree. Any tiny flaw in the data NASA presents tonight has the potential to cast doubt over the credibility of the entire discovery. Including the authenticity of the fossils.
Corkys jaw fell open. What are you talking about? Those fossils are irrefutable!
I know that. You know that. But if the public catches wind that NASA knowingly presented ice‑core data that was in question, trust me, they will immediately start wondering what else NASA lied about.
Norah stepped forward, eyes flashing. My ice‑core data is not in question. She turned to the administrator. I can prove to you, categorically, that there is no brine ice trapped anywhere in this ice shelf!
The administrator eyed her a long moment. How?
Norah outlined her plan. When she was done, Rachel had to admit, the idea sounded like a reasonable one.
The administrator did not look so sure. And the results will be definitive?
One hundred percent confirmation, Norah assured him. If theres one goddamn ounce of frozen saltwater anywhere near that meteorite shaft, you will see it. Even a few droplets will light up on my gear like Times Square.
The administrators brow furrowed beneath his military buzz cut. Theres not much time. The press conference is in a couple of hours.
I can be back in twenty minutes.
How far out on the glacier did you say you have to go?
Not far. Two hundred yards should do it.
Ekstrom nodded. Are you certain its safe?
Ill take flares, Norah replied. And Mike will go with me.
Tollands head shot up. I will?
You sure as hell will, Mike! Well be tethered. Id appreciate a strong set of arms out there if the wind whips up.
Shes right, the administrator said, turning to Tolland. If she goes, she cant go alone. Id send some of my men with her, but frankly, Id rather keep this plankton issue to ourselves until we figure out if its a problem or not.
Tolland gave a reluctant nod.
Id like to go too, Rachel said.
Norah spun like a cobra. The hell you will.
Actually, the administrator said, as if an idea had just occurred to him, I think Id feel safer if we used the standard quad tether configuration. If you go dual, and Mike slips, youll never hold him. Four people are a lot safer than two. He paused glancing at Corky. That would mean either you or Dr. Ming. Ekstrom glanced around the habisphere. Where is Dr. Ming, anyway?
I havent seen him in a while, Tolland said. He might be catching a nap.
Ekstrom turned to Corky. Dr. Marlinson, I cannot require that you go out with them, and yet‑
What the hell? Corky said. Seeing as everyone is getting along so well.
No! Norah exclaimed. Four people will slow us down. Mike and I are going alone.
You are not going alone. The administrators tone was final. Theres a reason tethers are built as quads, and were going to do this as safely as possible. The last thing I need is an accident a couple hours before the biggest press conference in NASAs history.