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Extraterrestrial Life

by Tom Jones 

This Christmas, the 3-D science fiction film Avatar is amazing moviegoers with its digital imagining of our civilization’s future encounters with an intelligent alien society, the Na’vi. In director James Cameron’s telling, these ten-foot-tall, blue-skinned beings inhabit the tropical moon Pandora, circling one of the giant planets of Alpha Centauri A, a Sun-like star just 4.4 light years from Earth.

Would the future discovery of such alien civilizations pose challenges for our faith in the Creator of our universe?

This artist's conception shows a hypothetical gas giant planet with an Earth-like moon similar to Avatar's Pandora. An alien moon orbiting the gas giant planet of a red dwarf star may actually be more likely to be habitable than tidally locked Earth-sized planets or super-Earths.

With the count of known extra-solar planets (exoplanets) now in excess of 400, astronomers believe it is just a matter of time and improving technology before we discover extra-solar analogs of Earth. NASA’s Kepler spacecraft, launched last March, is preparing to scrutinize 100,000 stars in the constellation Cygnus for evidence of Earth-sized worlds. Kepler’s sensitive photometer detects the minute drop in light from distant suns as Earth-sized planets pass in front of their parent stars. Those exoplanets discovered by Kepler will be examined by larger telescopes for traces of the chemical compounds, like water vapor, molecular oxygen, and methane, suggesting the presence of life.

In December, a team from the European Southern Observatory and the Harvard-Smithsonian Center for Astrophysics announced the discovery of GJ1214b, a “super-Earth” with six times our own planet’s mass, circling a star just forty light years from our Sun. GJ1214b is only three times Earth’s diameter, but its surface temperature is about 200 C, too hot for life as we know it. Shrouded by a stifling atmosphere, GJ1214b’s estimated density suggests the planet’s interior is comprised of 75% water ice surrounding a rocky core. Astronomers are closing in on the discovery of exo-Earths.

Moons around other exoplanets, similar to Avatar’s Pandora, may turn out to be excellent candidates for biology, says astronomer Lisa Kaltenegger of the Harvard-Smithsonian Center for Astrophysics (CfA). She calculates that NASA’s James Webb space telescope, scheduled for launch in 2014, will be capable of detecting gases like carbon dioxide, water vapor, and oxygen in the atmospheres of worlds that may be circling Alpha Centauri.

Prime targets for such an investigation will be planets or moons orbiting within a star’s habitable zone, neither too close to the parent star’s scorching heat, nor too far from its life-giving warmth. Inside this so-called “Goldilocks” zone, liquid water can remain stable for millions of years, one prerequisite for the origin of life.

Alien life has long been a staple of science fiction and Hollywood, but scientific findings are steadily reinforcing popular conjecture. A group of scientists at NASA’s Johnson Space Center thinks they have strong evidence in hand for life on Mars. In 1996, the team suggested that a meteorite recovered from Antarctica, ALH84001, a fragment of an ancient Martian lava flow, contained microfossils of bacteria-like organisms. The team cited accompanying chemical evidence suggesting life had once existed on Mars. In November, the team announced further experimental results supporting biological origins for minute particles of the iron-bearing mineral magnetite, found in ALH84001.

The NASA team argues that the simplest explanation of the magnetite’s crystal structure is biological activity, in the same way that some Earth bacteria secrete the mineral. Everett Gibson, a senior NASA scientist on the team, stated, “We believe that the biogenic hypothesis is stronger now than when we first proposed it 13 years ago.” This research and widespread evidence of water on Mars makes the red planet a prime target for future astrobiological investigation.

Trying to put these discoveries in the context of faith, I recall a lecture I attended in Houston last month, given by Brother Guy Consolmagno, S.J., an astronomer and meteorite expert at the Vatican Observatory.

In “Astronomy, God, and the Search for Elegance,” Brother Guy noted that intelligent life beyond Earth would be consistent with God’s power as Creator. We already have the example of the angels, sentient beings with free will, also formed in His image. To Consolmagno, our scientific search for life is a natural response to God’s invitation to play in His beautiful universe. 

The Vatican recently sponsored a timely conference on the topic of extraterrestrial life. Pope Benedict XVI’s chief astronomer, Father Gabriel Funes, stated last spring that alien life is compatible with our faith in the Creator, and its pursuit an important scientific endeavor. Should life be discovered elsewhere, Father Funes told the Vatican newspaper last year, that finding would be entirely consistent with God’s role in forming the cosmos:

Just like there is an abundance of creatures on earth, there could also be other beings, even intelligent ones, that were created by God. That doesn't contradict our faith, because we cannot put boundaries to God's creative freedom. As saint Francis would say, when we consider the earthly creatures to be our “brothers and sisters,” why couldn't we also talk about an “extraterrestrial brother”? He would still be part of creation.

Each time I voyaged into space, I looked back from the space shuttle’s crew cabin and marveled at the biological richness of the world spread beneath me. Gazing deep  into the clouds of stars filling the shuttle’s windows, I was convinced we will discover concrete evidence that life is an inevitable part of the limitless universe, a cosmos we are just beginning to understand. As a creature of the God who imagined and created it all, I find it energizing to know that even Avatar’s computer-generated universe can’t match the complexity and richness of the one God challenges us to explore.

Tom Jones is a planetary scientist, speaker, author, and veteran astronaut. His latest book is Planetology: Unlocking the Secrets of the Solar System (with Ellen Stofan; National Geographic, 2008). See www.AstronautTomJones.com

 

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(The views expressed in this column are those of the author and do not necessarily reflect the positions of Headline Bistro or the Knights of Columbus.)