Cosmology Bus

Mars, Methane, and Divine Revelation

This stop was to be about When Stars Came Down To Earth, but I'll get to that next time. The latest news concerning the Red Planet takes precedent this week.

Last Thursday, NASA held a press conference announcing that a project team had confirmed the presence of a large volume of methane in the atmosphere above the northern hemisphere of Mars. What's significant about the discovery is that methane, a greenhouse gas on Earth, is either biological or geological in origin. Researchers aren't sure which source is responsible for the methane above Mars -- it could be both -- but the fact there are such large quantities of it suggests that Mars isn't a "dead" planet after all; apparently there are natural processes at work below the Martian surface on a scale previously unknown.

Additionally, the prospect of a biological origin is exciting because it brings planetary scientists (and the rest of us) perhaps one step closer to answering the question if life exists beyond Earth.

The news conference followed a mulit-year investigation by scientists working with NASA's Infrared Telescope Facility and the W.M. Keck telescope, both on Mauna Kea, Hawaii. Analyzing spectrographic data collected over several Martian years, the team found three absorption lines (spectral features) that, taken together, are definitive signatures of methane. Moreover, the gas was detected in plumes above the surface in different northern regions, each of which shows evidence suggestive of ancient surface ice or flowing water. One plume contained an estimated 19,000 metric tons of methane, which is significant in part because, ordinarily, the gas is rapidly destroyed in the Martian atmosphere.

The volume is also significant because, according to team member Michael J. Mumma of NASA's Goddard Space Flight Center, the rate at which methane is released into the atmosphere during the Martian mid-summer is "comparable to that of the massive hydrocarbon seep at Coal Oil Point in Santa Barbara, California."

Coal Oil Point refers to the Coal Oil Point Seep Field in the Santa Barbara Channel, just offshore along the southern California coast. A seep field is a place where liquid or gaseous hydrocarbons -- for example, oil and natural gas -- bubble-up to the surface from cracks in the Earth's crust. Coal Oil Point is one of the largest seep fields on Earth.

So where is all the methane coming from? If the source is biological, the leading contender would be  bacteria or other extremophile microorganisms living far below the surface, where it is presumably warmer and liquid water exists. Team members point out that more than 90% of the atmospheric methane on Earth comes from living systems. At the press conference Mumma said,

"On Earth, microorganisms thrive about 1.2 to 1.9 miles beneath the Witwatersrand basin of South Africa, where natural radioactivity splits water molecules into molecular hydrogen and oxygen. The organisms use the hydrogen for energy. It might be possible for similar organisms to survive for billions of years below the permafrost layer on Mars, where water is liquid, radiation supplies energy, and carbon dioxide provides carbon. Gases, like methane, accumulated in such underground zones might be released into the atmosphere if pores or fissures open during the warm seasons, connecting the deep zones to the atmosphere at crater walls or canyons."

Geological processes on Mars that could produce methane include the conversion of iron oxide into sepentine minerals and volcanism. Mars isn't volcanically active today, but large volumes of methane created by volcanic activity earlier in the planet's history could be trapped below ground.

As I've mentioned before, one source of my own research interests in the confluence of science, religion, and the prospect of extraterrestrial life is writings and statements on these subjects in world religions, few as they are. When I heard the announcement on Thursday, it again brought to mind an excerpt from the Revelation of Baha'u'llah (1817-1892), the prophet and founder of the Baha'i Faith, who wrote:

"Thou hast, moreover, asked Me concerning the nature of the celestial spheres. To comprehend their nature, it would be necessary to inquire into the meaning of the allusions that have been made in the Books of old to the celestial spheres and the heavens, and to discover the character of their relationship to this physical world, and the influence which they exert upon it. Every heart is filled with wonder at so bewildering a theme, and every mind is perplexed by its mystery. God, alone, can fathom its import . . . Know thou that every fixed star hath its own planets, and every planet its own creatures, whose number no man can compute."

Because these words are directly from the prophet himself -- they were not written down by others years or decades after the fact -- members of the Baha'i Faith consider them to be sacred scripture. They appear in a volume titled Gleanings from the Writings of Baha'u'llah, which first appeared in English translation in 1935. Gleanings is just one of many published volumes of Baha'u'llah's writings available today.

When I first quoted this passage (12/3), I suggested that its impact on readers depends on who is reading and where they are on their own journey, spiritual or otherwise. Today, in light of the spectrographic analyses confirming the presence of methane on Mars and its possible organic origin in whole or in part, I would add that, for myself, anyway, Steven J. Dick's notion of the biological universe broadly complements what Baha'u'llah states in the last sentence.

Readers interested in learning more about the historical figure of Baha'u'llah and the process by which his Revelation was recorded for humanity can consult the Baha'i International Community website and "The Life of Baha'ullah: A Photographic Narrative."

The peer reviewed paper describing the NASA team's findings, titled "Strong Release of Methane on Mars in Northern 2003," will be published soon in the journal Science. Until then, a pre-publication version is available online at Science Express.

Next stop: When Stars Came Down to Earth

Conceptual animation depicting how biological organisms (shown as oval-shaped translucent structures) living beneath the surface of Mars may have produced methane (shown as blue spheres). Credit: Susan Twardy/NASA.

Banner bus photo credit: Dorothy Delina Porter.

Flight of the Phoenix

It’s almost official. On November 10, NASA announced that it had lost contact with the Phoenix Mars Lander, which effectively marked the end of a spectacularly successful mission on the Red Planet. As I write this, engineers at JPL in Pasadena, CA, are monitoring the spacecraft to see if its solar arrays can collect enough sunlight to allow it to call Earth one more time. But this isn’t likely, because Phoenix is in Mars’s north polar region, and the Martian winter is already in full swing. There isn’t much sunlight reaching the pole these days.

 

Over its five-month-long mission on the surface – two months longer than expected – Phoenix accomplished something unprecedented in the history of humankind’s investigations of Mars: it verified the presence of calcium carbonate, an indicator for liquid water and, using its robotic arm to dig, identified two different types of water-ice deposits beneath the planet’s surface.

 

The data collected by its sophisticated instruments and cameras will be studied for decades, but already scientists know the arctic region has soil that is mildly alkaline and contains salts that could serve as nutrients capable of supporting life. In sum, the Phoneix mission has brought scientists several steps closer to determining if the Martian polar region is -- or ever was in the past -- conducive for microorganisms.

Microbes.

 

On Earth we’ve known about them since the mid-17th Century (does the name van Leeuwenhoek ring a bell?), but in recent decades new ones have been discovered in some the harshest places on our planet. 

 

One recent discovery was announced this past summer at the annual meeting of the American Society for Microbiology. Jean Brenchley and Jennifer Loveland-Curtze, two researchers from Pennsylvania State University, described a new species of bacteria from Greenland that is so small it easily passes through today’s commonly used microbiological filters. These “ultra-small cells” are turning-up in surprising places. The Greenland bacteria were found living nearly two miles below the surface, encased in glacial ice that was determined to be about 120,000 years old.

 

These and other extremophiles have been found in a suprisingly wide variety of unforgiving environments on Earth: low-oxygen, no-oxygen, high-pH, low-pH, no-light, high-pressure, etc. In 2006, a team from Princeton University found bacteria that obtain all their nourishment from hydrogen and sulphur compounds derived from naturally decaying radioactive rock. These also live about two miles below ground, in South Africa.

 

Apart from sometimes being amazingly tough creatures, microorgamisms constitute a major proportion of life on Earth. According to Loveland-Curtze, "Microbes comprise up to one-third or more of the Earth's biomass, yet fewer than 8,000 microbes have been described out of the approximately 3,000,000 that are presumed to exist."

 

So many microbes, so little time, as the microbiologists say.

 

But for me, what’s really intriguing about the extremophiles we’ve discovered here is the prospect of analog microorganisms living beyond Earth, perhaps in our own solar system.

 

Probably the most thought-provoking – and certainly entertaining – book I’ve read on this subject is David Grinspoon’s Lonely Planets: The Natural Philosophy of Alien Life, which won a Pen Center USA literary award when it appeared in 2004. I highly recommend it (see sidebar). Grinspoon is a planetary scientist and Curator of Astrobiology at the Denver Museum of Nature & Science. In Lonely Planets he not only effectively presents the big picture on a wide range of subjects that pertain to how we think about life on and off our planet – microbial as well as complex forms having (dare I say it?) “intelligence” – but he also reminds us of the value that natural philosophy, or a natural philosophical approach, can bring to the subject.

 

Natural philosophy will be explored in future posts. It’s worth several stops, in fact.

 

BTW, Grinspoon's site is worth a visit, too.

 

Meanwhile, Phoenix sits silently on the Martian arctic plain, buffeted by winter winds in near-dark conditions. I applaud the lander’s many accomplishments, but I also wonder if something similar to, but different than, an Earth-bound microorganism occupies a void in the rock and ice a mile or more beneath its frozen footpads.

 

Perhaps we need to dig deeper.

 

Next stop: More good reads 

 

Banner bus photo created by Dorothy Delina Porter