Today at Brown

HVALFJORDUR [Wednesday, August 27, 2008] — You could forgive Jack and Bethany if they just wanted to catch some Zs.

They had flown the red-eye from Boston to Iceland, arriving shortly after dawn. It would do them good to sleep, relax, and prepare for the next day’s long drive to the central interior of Iceland.

But Jack and Bethany are dedicated scientists, and they had a little riddle they wanted to solve.

Some time before, Bethany had been poring over data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), an instrument that had orbited Mars on a spacecraft. She kept seeing signs of minerals called zeolites scattered throughout the Nili Fossae region of Mars and in craters in the planet’s southern highlands. Another instrument had detected signs of zeolites, but the signals picked up by CRISM were much more convincing.

On Earth, zeolites are used by the petrochemical industry for water softening and purification, and in the separation and removal of gases and solvents. The possibility of zeolites on Mars interests scientists because it would support the water-on-Mars argument. Zeolites interact chemically with water in benign, non-acidic conditions — in other words, in an environment suitable for primitive life, such as microbes.

Looking for clays under a rocky overhang. Evidence of clay-like minerals has been found on Mars. Bethany had come across a paper about zeolite deposits in the hills outside Reykjavik. So, instead of resting, the scientists went hunting for zeolites.

We drove in the ATV to Hvalfjordur, a winding strip of water surrounded on both sides by sloping green terrain with long lines of exposed rock faces. Bethany and Jack spied a promising cut marked by a waterfall. We parked next to a picnic table on the side of the highway, crossed the road, hopped a sheep fence, and began to amble up the slope.

Grasses grew wild among exposed rocks covered with lichens. The ground felt squishy, as if we were walking on thick pillows. We scrambled up the cut, skidding on loose rocks and holding onto boulders and rock faces.

Periodically Jack and Bethany would grab a rock and examine it. They were looking for white, quartz-like markings that could signal the presence of zeolites. They whacked some of the rocks with a hammer and gazed inside at the vesicles, pores that once held air bubbles that escaped as the lava cooled, “like gas in a soda bottle,” Jack explained.

Nearly every rock we inspected was pockmarked with vesicles. A lot of lava had flowed here — no surprise considering Iceland sits atop a major global fault line that has spawned epochs of volcanic rage.

After collecting rocks, the scientists returned to the side of the road for in-depth analysis. On the picnic table Bethany opened a metal suitcase to reveal a laptop and a spectrometer. Jack took charge of the spectralon, a slender device that looks like a sophisticated flashlight with a grip handle similar to those on a jump rope.

Jack shined the spectrolan’s light on the exposed area of each sample, and the spectrometer “read” the rock’s guts, operating in the visible to the near-infrared spectrum (500-2,500 nanometers). Bethany recorded the samples and reviewed each reading with Jack. She then put each sample in its own plastic bag, numbering, dating, and marking its collection location.

Of 16 samples the scientists examined, at least one seemed to be suggest the presence of zeolites. Another rock gave the duo a surprise, spitting out absorption at 2.5 microns — the same as the absorption rate of rocks on Mars.

“That one could be the bonus package,” Jack said.

The double waterfall at Gulfoss drops more than 100 feet. We visited two more sites, hopping fences and scrambling up rock faces and narrow cuts graced by waterfalls. After a few hours, Jack and Bethany were satisfied. They had found many samples that held tantalizing signs of zeolites, as well as some glittery black deposits they were anxious to scrutinize later.

There was still time for a bit of tourism. We drove to Geysir, a spot in a wide, green valley with rows of geysers, including one that belched an impressive fountain of scalding water every eight minutes. Just down the road, we visited Gulfoss. This double-decker waterfall is not on a par with Niagara Falls in terms of volume, but it beats the U.S.-Canada attraction with its utter lack of commercialization and kitsch.

Icelanders apparently like to keep it natural. We appreciated the thought as we returned to the vehicle and began our journey back to Reykjavik.