Recently, the scientific community became excited over startling new evidence that life not only once existed on Mars, but may exist there today.
Now, evidence has surfaced that another of Earth’s neighbors may be harboring life: Titan, the largest moon of Saturn and the only moon known to have a dense atmosphere.
Methane lakes and the acetylene puzzle
The world of Titan is indeed strange. A planet of hydrocarbons with liquid methane and ethane lakes and slightly smaller than Earth, Titan would be considered a planet if it were not orbiting the gigantic ringed world, Saturn. Titan is eerily Earth-like with mountains, valleys, rivers and lakes.
For some time scientists have speculated that Titan’s lakes might support amazingly exotic life.
Now Cassini, the orbiting space probe sent years ago to conduct an intensive long term study of Saturn and its moons has sent back data containing two possible signatures of life on the planet-sized moon. Although the data could indicate the presence of life-forms inhabiting Titan, many scientists caution that another explanation could be simply geologic in nature-not necessarily one caused by biological chemical actions.
The reason for the excitement and belief that life may exist on Titan can be traced back to a 2005 research paper written by Chris McKay of NASA’s Ames Research Center in Moffett Field and Heather R. Smith of the International Space University in Strasbourg, France. The two scientists postulated that if life did exist on Titan, it would most likely be in the form of microbes that would breathe hydrogen gas and ingest acetylene, an organic molecule. The waste product of such microbes would be methane. The two suggested that a dearth of acetylene would be a very large clue that life existed there.
The new Cassini data has found the evidence that McKay and Smith suggested might exist. The spacecraft’s Visual and Infrared Mapping Spectrometer (VIMS), measuring Titan’s surface in the infrared spectrum of light, detected no acetylene. Ultraviolet rays from the sun, however, would constantly generate acetylene as it passed through Titan’s dense atmosphere.
The hydrogen anomaly
Meanwhile, measurements of Titan’s hydrogen gas turned up a surprising anomaly: while some of the gas is rising and escaping the moon, a portion of the hydrogen is falling to the surface. Instead of pooling near the ground the hydrogen is disappearing. This leads scientists to believe that something on the surface is consuming it. The new evidence was recorded by Cassini’s Ion and Neutral Mass Spectrometer and its Composite Infrared Spectrometer instruments.
McKay told a “New Scientist” reporter that it’s evidence of “very unusual and currently unexplained chemistry,” And it’s “Certainly not proof of life, but very interesting.”
Scientists admit that a lot of work must still be done before anyone can pronounce whether or not Titan has life. As Mark Allen of NASA’s Jet Propulsion Laboratory in Pasadena, California notes in a NASA press release, “Scientific conservatism suggests that a biological explanation should be the last choice after all non-biological explanations are addressed.”
A stinking, poisonous lake
Recently, scientists discovered life in a Trinidadian lake made of hydrocarbons. Researchers enthusiastically point to the thick, tar lake called “Pitch Lake” located on the West Indies island just north of Venezuela as proof that life could also exist on Titan. Locals tend to avoid the area calling it a stinking, poisonous lake.
Mostly archea and single-celled bacteria, the tiny life forms in Pitch Lake live without oxygen and feed off hydrocarbons.
A metaphysical Disneyland
Exobiologists are thrilled with the concept that both Mars and Titan may have life, or once did. The metaphysical implications of three worlds in one solar system supporting life would make it a given that life exists throughout the universe in countless forms and numbers.
The likelihood of intelligent life is also greatly boosted. If life of any sort is a natural occurrence within all the star systems throughout all the galaxies of the universe, then billions—if not trillions—of intelligent lifeforms have existed, do exist and will exist.
As Professor John Zarnecki, of the Open University, observed about the probability of life on Titan, ‘We believe the chemistry is there for life to form. It just needs heat and warmth to kick-start the process.”
