Martian methane

From LiveScience.com: Mars Methane: Geology or Biology?

Plumes of methane gas detected over certain locations on Mars in 2003 could point to active geological processes on the red planet, or perhaps even to methane-burping microbes deep below the Martian surface, a new study reports.

There is no firm evidence for life on the red planet, however, despite news reports early today suggesting as much. Rather, scientists are puzzled by the new findings.

The methane gas is concentrated in small areas of the northern hemisphere of Mars, suggesting it is released from deep fractures or from only limited areas of soil; and that it breaks down over time in the atmosphere. Additionally, these releases of gas occur only in the summer.

It is best to have multiple working hypotheses in a situation like this. Here are some possibilites:

  • Shallow geochemical processes in the soil.
  • Deeper geochemical processes or reservoirs of methane, with release occurring when ice in the subsurface melts.
  • Magma in the subsurface (though this is unlikely as other volcanic gases have not been observed in these plumes).
  • Biological activity. On Earth, bacteria in the subsurface rely on chemosynthesis, which is like photosynthesis, except that the energy source is oxidation of inorganic molecules rather than sunlight.

Discovery of bacteria on Mars, of course, would be a major discovery. The next question would be, how did it get there?

A perspective from Reasons to Believe can be found here: Bacteria or Boulders? Methane and Life on Mars. I have two disagreements with Fazale Rana’s RTB article:

  • He seems to jump to the conclusion that the geological answer is the correct one. It may be, but this seems a bit premature.
  • He states: “Rather than life-confirming methanogens, it seems that boring rocks may be responsible for Martian methane.” I object. Rocks aren’t boring!!!

Grace and Peace

Rare Earth?

Many Christians, including myself, find the arguments expressed in the 2003 book Rare Earth to be a powerful statement of the uniqueness of the Earth in the universe. The thesis of the book, written by two respected University of Washington scientists (Ward, a geologist, and Brownlee, an astronomer) is that the conditions present on the surface of the Earth that make it habitable for advanced life are likely to be very rare, or even unique, in the universe. For a planet to have advanced life–organisms more complex than bacteria–it must orbit at the right distance from the right kind of star, have the right sized moon for stability of orbit, have the right core, and so on. Perhaps, say the authors, we are all alone in the universe after all.

Christians have latched on to many of these same ideas. The writings of Hugh Ross of Reasons to Believe, and of Guillermo Gonzalez (The Privileged Planet, book and DVD) contain many of the same arguments for the uniqueness of planet Earth. The argument goes that apart from the intervention of God, the universe is a dangerous place. Perhaps there is only one place in the universe that is suitable for humans, and that is because God (not chance) has orchestrated it to be so.

I find these arguments to be strong, and Rare Earth is one of my favorite geology books, one I highly recommend. I also acknowledge, both scientifically and theologically, the concept could possibly be flawed. From a theological perspective, we cannot argue persuasively that there is only one Earth-like planet in the universe. Earth might be unique, it might be rare, or the universe might abound with advanced life. Note that I am not talking about intelligent life right now, only advanced, multicellular life. Could it be that our Milky Way Galaxy contains millions of planets that are suitable for everything from bacteria and algae to forests and flocks of birds? Perhaps in the initial creation, and in the future new Heavens and new Earth, the universe was made for humans to explore and thrive in. We just simply do not know.

Not all scientists agree with the rare Earth hypothesis. Many astrobiologists believe that the universe is filled with life. Though I presently find the arguments for a rare, or even unique, Earth to be strong, I do acknowledge that this hypothesis could be wrong.

Part of the problem right now is that we don’t have that much data to work with. We now know of hundreds of stars that have their own solar systems. Since the 1990s, we have been able to detect large planets orbiting around stars by the wobble of the stars produced by the strong gravitational field of the giant planets. Most of these discoveries have been Jupiter-sized planets orbiting their stars at searingly close ranges, and in most of these solar systems there would be no chance for the existence of terrestrial planets. With our current instruments, we cannot planets the size of Earth.

That should change just a little bit in 2009. NASA will be launching the Kepler Mission, which is a space telescope designed to simultaneously observe about 100,000 stars, watching for transits of planets across the faces of these stars. As even an Earth-sized planet passes directly between the star and the Earth, there will be a slight diminishing of the intensity of light observed. The Kepler Mission will not allow us to see the planet directly, but will enable us to determine the presence of the planet, and to infer its size and orbit. Knowing the nature of the star itself, and the parameters of the planet’s orbit, we would be able to determine if the planet were in the star’s “habitable zone,” that not-too-close, not-to-far region that allows liquid water to exist on a planet’s surface.

This won’t tell us whether the planet has life; spectrometers sensitive enough to detect things like an oxygen-rich atmosphere at distances of many light years lie in the future. What it will enable is a tightening of some of the variables that go into the debate between a rare Earth and a green universe.

As Christians, we can rejoice in God’s creation whether we see God’s providence in an Earth that is a unique,  protected oasis in a hostile universe, or if we discover a multitude of worlds touched by God’s creative Spirit (but still oases in a hostile universe). The rare Earth hypothesis may still turn out to be sound, but I’m not going to have any kind of theological struggle if it turns out to be wrong.

NASA Kepler Mission

Live Science: How Rare is the Earth?

Wikipedia: Kepler Mission

Image: The Kepler Spacecraft, NASA image from Wikipedia

Image: The Kepler target region, from kepler.nasa.gov

Grace and Peace

Life in the Laboratory

From an AP news story on efforts by scientists to create life “from scratch” in the laboratory:

Around the world, a handful of scientists are trying to create life from scratch and they’re getting closer.

Experts expect an announcement within three to 10 years from someone in the now little-known field of “wet artificial life.”

I was contemplating writing about this news article, but Glenn (PhD, biochemistry) at Be Bold, Be Gentle beat me to it, and did a better job than I could have done. Glenn includes a joke which brings home a good point.

Grace and Peace

Life on Gliese 581c?

The headlines:

Science Daily: New Planet Could Have Life

Yahoo News: Potentially Habitable Planet Found

Scientists have discovered more than 200 extrasolar planets (planets orbiting stars other than our sun) since the mid-1990s, and the numbers will certainly continue to increase as instruments improve. In regards to suitability for life, a vast majority of these planets are too large, too hot, or too cold; this is called the Goldilocks problem. Today, astronomers at the European Organisation for Astronomical Research in the Southern Hemisphere (ESO) announced that they have discovered a planet that might be “just right.”

The planet orbits a red dwarf star named Gliese 581, and it has been given the name Gliese 581c. Red dwarfs are smaller and cooler than our sun, and 581c orbits within what is called the “habitable zone,” which is the region around the star where it is possible to have liquid water on the surface—neither too hot nor too cold. The astronomers believe it is one of three planets that orbit Gliese 581; the others are designated 581a and 581b. The telescopes we have are not powerful enough to directly view extrasolar planets, but the astronomers infer their existence by watching the stars “wobble” under the influence of the gravity of the planets.

How does this relate to life in the galaxy? It is widely believed among exobiologists—those scientists who speculate about life elsewhere in the galaxy (certainly not to be confused with UFO-ologists)—that in order to have life, one needs liquid water. If a planet is too close to its star—or too far away—then conditions are not right to have living organisms, at least not on the surface of the object.

It also needs to be made clear that these astronomers are not talking about intelligent civilizations on worlds like Gliese 581c. The universe might have an abundance of places that are suitable for bacterial slime, and Gliese 581c might be one of them. The conditions required for advanced life—anything more complicated than a Paramecium or Amoeba—are likely to be exceedingly rare in the universe.

My thoughts:

  1. The results are very preliminary. We don’t have any direct measurements of the planet’s temperature. If it has a CO2-rich atmosphere, it could still be too hot, even being within the habitable zone.
  2. In the future, as instruments become more powerful, it might be possible to analyze light from planet such as this. If spectrographic analyses indicate presence of both water and atmospheric oxygen, this would greatly increase the probability that there is life of some sort on the planet.
  3. I would not see the discovery of primitive life on a world such as Gliese 581c as having any negative theological implications. Everything from Genesis 1:2 on is very Earth-centered, and so the Bible doesn’t say anything one way or the other about whether life exists on other worlds.


Artist’s conception of a planet orbiting a red dwarf, from hubblesite.org

Grace and Peace

Water on Mars

Today’s Astronomy Picture of the Day shows two images taken by the Mars Global Surveyor. A comparison of the same crater in 1999 and 2005 shows that there is an active slope process occuring in a crater, and many interpret this to be a brief flow of liquid water down from the rim. Liquid water, of course, is essential for life, and this increases the chances for finding life on Mars.

A few observations:

  • There are alternative slope processes that could have caused the white scar, such as a simple landslide. A majority of workers think this is from water, but this could be because they want it to be caused by water.
  • Due to the low atmospheric pressure on Mars, water cannot exist for long as a liquid on the surface, even at temperatures above zero Celsius. On Mars, water will behave like dry ice (solid carbon dioxide) does on Earth. Rather than going from solid to liquid to gas as it is heated, it will go directly from solid to gas (sublimation). This is not to say that liquid water cannot exist on the Martian surface for brief amounts of time.
  • If there is life on Mars, it will likely be similar to bacteria on Earth.
  • If there wasn’t life on Mars before, it could be there now. Despite precautions, there is a chance that bacteria from Earth could have survived the journey on one of the probes that have landed on the surface.
  • Interplanetary contamination might occur naturally as well. We have meteorites on Earth that came from Mars; and Mars likely has meteorites that came from Earth. It is possible that bacteria could survive this trip.
  • There is no reason for Christians to be concerned about this type of research. There is no reason, Biblically, why there couldn’t be simple life scattered througout the universe.
  • Astronomy Picture of the Day has offered a more convincing image of “water on Mars” in the past:

Grace and Peace