'Bite me twice,' Norah whispered.
The administrator approached, his furry eyebrows lowering. 'What's wrong with the ice data.'
Tolland heaved an uncertain sigh. 'We're showing a three percent saltwater mix in the meteorite shaft, which contradicts the glaciology report that the meteorite was encased in a pristine freshwater glacier.' He paused. 'There's also plankton present.'
Ekstrom looked almost angry. 'Obviously that's impossible. There are no fissures in this glacier. The PODS scans confirmed that. This meteorite was sealed in a solid matrix of ice.'
Rachel knew Ekstrom was correct. According to NASA's density scans, the ice sheet was rock solid. Hundreds of feet of frozen glacier on all sides of the meteorite. No cracks. And yet as Rachel imagined how density scans were taken, a strange thought occurred to her…
'In addition,' Ekstrom was saying, 'Dr. Mangor's core samples confirmed the solidity of the glacier.'
'Exactly!' Norah said, tossing the refractometer on a desk. 'Double corroboration. No fault lines in the ice. Which leaves us no explanation whatsoever for the salt and plankton.'
'Actually,' Rachel said, the boldness of her voice surprising even herself. 'There is another possibility.' The brainstorm had hit her from the most unlikely of memories.
Everyone was looking at her now, their skepticism obvious.
Rachel smiled. 'There's a perfectly sound rationale for the presence of salt and plankton.' She gave Tolland a wry look. 'And frankly, Mike, I'm surprised it didn't occur to you.'
42
'Plankton frozen in the glacier?' Corky Marlinson sounded not at all sold on Rachel's 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.
'What's 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 we're 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 everyone's a glaciologist!'
Corky also looked skeptical. 'But wouldn't 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 PODS's 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 you're wondering if G. polyhedra is capable of hibernating inside the ice? You'll 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 Norah's tone, there was obviously some sort of 'but'-and yet it seemed she had just confirmed Rachel's theory.
'So,' Tolland ventured, 'you're saying it's possible, right? This theory makes sense?'
'Sure,' Norah said, 'if you're 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.' Norah's 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 can't get any closer.'
'Just asking.'
'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, Rachel's 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 she'd 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 can't say it is.'
