Bacteria Discovered in Lake of Oil: Implications for Extraterrestrial Life?

Pitch Lake in Trinidad, where life has been found inside water droplets within the oil deposits. Photo Credit: Martina Jackson/Wikimedia Commons
Pitch Lake in Trinidad, where life has been found inside water droplets within the oil deposits. Photo Credit: Martina Jackson/Wikimedia Commons

A recent discovery by scientists may have implications for possible extraterrestrial life: Bacteria have been found thriving in a lake of oil in Trinidad, again showing how life can exist in even the most inhospitable conditions on Earth. The discovery brings to mind the similar environment on Saturn’s moon Titan, where lakes and seas of liquid hydrocarbons (methane/ethane) exist at the moon’s poles.

The new findings were just published in the journal Science by an international team of scientists who studied Pitch Lake, a natural liquid asphalt lake in Trinidad, and found microorganisms (bacteria and archaea) living in tiny water droplets within the oil deposits. There is relatively little water in the lake, so the discovery of such a thriving ecosystem was unexpected. Yet these miniscule water droplets are apparently more than enough to sustain microbial life within them, even though the surrounding oil is full of toxic compounds.

“Oil was considered to be dead,” according to lead study author Rainer Meckenstock, an environmental microbiologist at Germany’s Helmholtz Zentrum München. “The microbes most likely were enclosed in droplets in the deep subsurface and ascended together with the oil.”

The water droplets are also highly salty, and their isotopic composition suggests that the oil originates from deep in the subsurface below the lake. On the surface of the lake, methane bubbles are also released into the atmosphere, after microorganisms have altered the chemical composition of the oil, which rises up to the surface from the lake bottom.

Ligeia Mare, one of the largest methane/ethane lakes on Titan as seen by the Cassini spacecraft. Image Credit: NASA/JPL/USGS
Ligeia Mare, one of the largest methane/ethane lakes on Titan, as seen by the Cassini spacecraft. Image Credit: NASA/JPL/USGS

There is a place in the Solar System which has conditions similar to this: Saturn’s largest moon Titan. The environment is much too cold for liquid water on the surface, but instead there are lakes and seas of liquid hydrocarbons, methane, and ethane. There are even rivers and rainEarth-like in appearance but very different in composition. But since these are bodies of liquid, it has been questioned whether some form of life could exist in them, perhaps methane-based. The idea is a tantalizing one, even if still just speculative.

The extreme cold is certainly a limiting factor, but the results from the lake in Trinidad show that the possibility shouldn’t be discounted. The Titanian lakes may also contain tiny droplets of water, which would otherwise be frozen solid on the ground. We just don’t know until another mission can go there and examine them up close. Or perhaps life could do just fine in the lakes themselves and not even need water.

Titan’s atmosphere also contains a lot of methane, and the source of it is still unclear. While scientists know it is being regularly replenished, it is assumed by most that it is geological in origin. What if bubbles of methane were also being released into the atmosphere from the lakes and seas in a way similar to the lake in Trinidad? Purely hypothetical at this point, but interesting to think about.

There is also the previous finding that hydrogen, abundant in Titan’s atmosphere, seems to somehow disappear at the surface, as if something is consuming it, like what happens on Earth with nitrogen/oxygen. Some scientists have suggested this might be evidence for life of some kind, although there are still other explanations possible. Titan is a very mysterious and alien world.

Adding to the possibilities, there is now thought to be a subsurface ocean of salty liquid water deep below the surface of Titan, something like Europa or Enceladus. Even if the surface is completely devoid of life in such harsh conditions, this ocean may be a more suitable habitat. Very little is known so far about the actual conditions down there, so again everything is conjecture until we can return to Titan and explore it better with more advanced probes.

The abstract/paper is available here.

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3 Comments

  1. I love the possibilities of your article Paul, so many absolutely mind-bogglingly intriguing questions, so much incredible history-making exploration just waiting. We have the genius in our NASA engineers and scientists, we have the money, all that is lacking is the will and the intellectual curiosity from the sports/twerking/selfie obsessed American public. If NASA could accept private donations, and if the TiME mission could be approved, my check would be in the mail!

    • Karol,
      I share your enthusiasm …But I wonder why NASA has done so much with so little do we continue to prevent NASA from doing more?…I don’t think it has anything to do with lack of support by the public rather a leadership that is beholden to “groups” that are threatened by technological advance that would reduce their level of cash flow or power and control over their kingdoms….

  2. Amen, Karol! Titan, Europa and the other moons are begging us to explore them! We should immediately set forth on such missions and allow the next generation of scientists and engineers to fully utilize advanced technologies in order to answer the important question about our place in the cosmos.

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