This far, the expedition had been a highly successful failure. Five weeks into the exploration with three weeks of intense survey had brought a wealth of data, but not what they had come for. Olympus Mons or Nix Olympica, the Olympic Snows as it was formerly known, had stubbornly refused to accede to human wishes. True, Elena Trofimova had identified the REE-carrying minerals Monazite and Bastnäsite on the very first day, but only in microscopic crystals a few microns in diameter. Of the hoped-for pegmatites and carbonatites where such minerals would collect in small but large-enough pockets to mine, there was no sign.
The weather had held for all but two days of the first ten days with dust devils few, minor and far between, which had allowed Yaema and Adewele to run the tether along the southern slope of the gigantic landslide to a point above of the failure of the mountain. Rover A had been released on the fifth day at a point close to the escarpment from where it had run up as close to it as possible. The images and rock sample analyses it data-linked back over the next few days painted a picture of a very unstable slope of loosely bonded layers of volcanic, basaltic tuffs.
– ‘You have to realise that on Mars, the very low atmospheric pressure means that even minor basaltic eruptions would erupt in violently Strombolian fashion’, Yelena had said as they discussed their findings one evening. ‘Forget lava flows like those video recordings of Earth’s Hawaii show! Anything larger and you’d have Peléean to Plinian eruptions. Take that clip of Etna from 2002 where she sent glowing fountains some 400 to 800 metres high! This baby would send her fountains many kilometres high, possibly even higher than 20 km, and you’d get Nuees Ardentes or pyroclastic flows. As they run down the slopes, they’d form tuffs. But the farther from the summit you get, the cooler they become until they don’t weld at all. Close to the summit, they’d weld strongly and collect thickly. You might even get lava flows from the larger and hotter debris such as lava bombs and they could theoretically have run a very great distance. That’s why it is shaped like it is with the degree of incline increasing the closer you get to the summit. But at a point about 250 km from the summit, they’d not weld at all. That’s why you have this huge scarp. Any major disturbance at all and it collapses and the height from which it does so ensures that the debris avalanche travels hundreds of kilometres. Here, look at this!’ She had called up an image almost a century old.
– ‘But if they knew all that a century ago, what are we doing here?’
– ‘Because this whole area is covered by a layer of fine dust, Adewele.’ Gerry chuckled to himself. ‘It blocks the view of the finest, most sophisticated and high resolution spectrographs even you could dream up. No chance of getting a detailed view of the geology. That’s why we have to eyeball it.’ He squeezed Yaema’s hand.
Yaema gave her partner a quick hug. ‘That reminds me of one of those physics experiments we did when we were kids, remember? We’d have a fan and grab a fistful of sand which we let trickle slowly into the path of the air. The lightest particles were carried the furthest while the heaviest fell closer. Elena, think those distant debris fields might be a better place to look for REEs?’
– ‘Could be. But we’ll have a better idea once we’ve done the seismic survey.’
Each of the rovers carried a video camera, a spectroscopic camera, an infrared camera, a sampling device and miniature lab plus a set of six seismic charges. After being deployed, each would be remotely detonated and fire a hollow charge plasma jet travelling at speeds up to 11 km per second into the ground. The seismic shockwave would travel through the ground to be picked up by a network of seismometers deployed by the rovers, each of which could carry a single one. These would then be left behind to offer continuous monitoring of the giant volcano. Although Olympus Mons probably had been as dead as the proverbial dodo for several billion years, it was better to be safe than sorry if a mining base was to be set up somewhere on her slopes.
On the eighth day, there had been an accident. Rover A had been deployed as soon as the Graf’s tether had reached the closest exposed part of the scarp and had explored it visually for a distance of some twelve kilometres. In order to test the Seismic Survey System, the Triple-S, a charge had been set close to the exposed face of the scarp after which the rover had been parked about 250 m downhill. One reason they had parked so close was that they had wanted a visual of the event. As the charge had gone off, so had a tiny portion of escarpment and Rover A was now buried under a few hundred metres of debris. Because of the landslide, the data had seemingly been too muddled to interpret.
Ten days into the expedition, the cable tether had been ready and the fleet of seven remaining rovers were deployed by the Graf driven by Yaema. Even if the rovers could theoretically cover between 25 and 40 km, dependant upon the terrain, per Martian solar day or sol of 24h 39m 35.24409s, the automated search pattern and frequent investigations along their respective paths had slowed them down to between five and ten km per day. They had sent back amazing images of the upper slopes that seemed to be covered by tens of thousands of small yet very long “flows” of debris matter that had coalesced in a manner reminiscent of the images they had seen of Earthly lava flows at Emi Koussi, a tall pyroclastic shield volcano at the southeast end of the Tibesti Mountains in the central Sahara of northern Chad, the most Mars-like of Earth’s volcanoes. Rover E had encountered what looked like the exit of a lava tube at the highest point. Unfortunately, the rough terrain had precluded a closer look, so a tantalising glimpse from almost a kilometre away was as close as it got.
– That has to be a primary target for a follow-up expedition! Imagine for how long that could run!’ Adewele was over the moon with the discovery and equally frustrated that he could not get the rover inside.
– ‘Moemo ljubov,’ Elena gave her mate a playful hug. Adewele’s obsession with driving remotely operated vehicles was a standing joke with them. But he was the most skilled operator of the colony, that’s why he and they were on this expedition. ‘I’m certain that had it got in there, you wouldn’t have noticed if the rest of us had packed up and gone home. Besides, it’s not a lava tube but the crater left behind as a dike came close enough to the surface to explosively decompress. Your malenkoe little rover would probably not get more than a hundred metres in before it got terminally stuck.’
In locations where erosion had removed the ubiquitous landslide topsoil to reveal hints of the underlying geology, the mineral sampling had confirmed Elena’s initial hypothesis of pyroclastically deposited tuffs that were decreasingly less welded the farther one got from the summit. Only Rover F had encountered what was definitely identified as the final tendrils of an ancient lava flow and a sample returned contained large enough grains of Zircon for Elena to tentatively identify them as “low” or metamict zircon via IR-spectroscopy, crystals where the radioactive decay of the minute amounts of Uranium 238 and Thorium impurities present had altered the crystal structure. For this to take place, at least 4.5 x 10^18 decay events per gram of zircon must have occurred, something that takes billions of years. Should X-ray diffraction back at Olympia confirm this analysis in the field, it would be definitive proof that Olympus Mons had been extinct for several billion years.
When the seismometers had been emplaced by the rovers, these were turned back and the Triple-S charges deployed at least ten km distant from any sensor. Once the rovers had returned to the collection point – waste not, want not – the charges were set off at intervals of five minutes to allow for easy separation of the data amidst high tension amongst the crew. But the data returned had proved to be disappointing. Instead of revealing possible locations of solidified and well-fractionated magma chambers with bodies of mineable ore beneath the mountain, the data had been jumbled as if reflected from a myriad of different strata within the first few kilometres.
– All we can say from this data is that Olympus Mons is a basaltic, pyroclastic stratovolcano that masquerades as a shield volcano and that it has been extinct for billions of years’, Gerry concluded. ‘There’s no sign of anything deeper than a kilometre or two. Even if we know that the point of neutral buoyancy is at ten km and that any magma chamber thus has to be ten km below the summit and at least ten km up vertically as counted from the base of the escarpment, we cannot locate it. We’ve drawn a blank. Time to go home, crew!’
– ‘Hello? What is this? Look at it!’ Yaema had been driving the Graf down the tether, loaded with the recovered rovers. The early summer morning sun shone on the escarpment and the point where the recent landslide that buried Rover A. The reflection was so bright it blinded the blimp’s forward looking camera, which had to be turned away.
– ‘Elena, are you thinking what I’m thinking?’
– ‘Yes! There can only be one explanation, water ice! Bozhe moi! No wonder it’s so fragile. Thin glaciers, covered by pyroclastic deposits not hot enough to brew chai on. Then another layer of glacier and so on. No wonder the Triple-S returned meaningless data!’
– ‘Yes, but consider the amounts and accessibility! And what are the odds that it’s laced with helium too, possibly even isotopic, the Helium 3 required for fusion? Not only do we have drinking water and rocket fuel. With any luck, we have unlimited power too!’
– ‘Yes Gerry, but there’s also the possibility to extract minerals dissolved in that water, especially the lower layers at the bottom of the scarp. We have to get samples of this!
Gerry embraced Yaema, then turned to Elena and Adewele. ‘I don’t know about you guys, but to me that escarpment means children and a safe future for them. Hopefully, we’ll find those REEs too. If not, there’s always tomorrow.’
Man has come to Mars to stay indefinitely.
Henrik & Albert
This episode is dedicated to our friend Sissel who would not wish us to dawdle with its publication.
(In Part III, we will look at all the facts upon which this work of fiction has been based, the “Science behind” even if science should always take precedence over the dramatic effect.)