Module 5 - The Search for LifeMain MenuLife, the Universe and EverythingThe search for extraterrestrial intelligent lifeIngredients and requirements for lifeFrom Building Blocks to Self-ReplicationExtremophilesBlack SmokersMono LakeRio TintoFrom habitability to searching for signs of life on MarsLife on Venus?Life in the outer solar systemTitanAnother quick look at exoplanetsSummaryFrank Fuetendee05431475b87c68ebf15bbea4bfeac11808e9eMariek Schmidt3b678a5bd42eb8bf9a55fb761e5f17b11ce872c1
Giant red tubeworms
12016-05-04T10:27:59+00:00Frank Fuetendee05431475b87c68ebf15bbea4bfeac11808e9e151A black smoker community comprised of giant red tubeworms and hundreds of squat lobsters. This vent is located in Strawberry Fields of the Main Endeavour hydrothermal field on the Juan de Fuca Ridge. Vibrant colonies of tube worms with red gills thrive on this vent which is predominantly composed of iron- and sulfur-bearing minerals. Credit: University of Washington; NOAA/OAR/OER.plain2016-05-04T10:27:59+00:00National Oceanic and AtmosphericThis image is in the public domain and cannot be copyrighted.Frank Fuetendee05431475b87c68ebf15bbea4bfeac11808e9e
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1media/Blacksmoker_in_Atlantic_Ocean.jpg2016-04-05T10:11:25+00:00Black Smokers20image_header2022-04-04T19:24:39+00:00Arguably the most dramatic extreme environment on Earth is one we knew nothing about until 1977 when the submersible Alvin discovered Black Smokers on the East Pacific Rise, a mid-oceanic ridge in the Pacific Ocean at a depth of 2.6 km. Here, tectonic plates are separating at a rate of 7.5 cm/year. When plates separate, new oceanic crust (in the form of basaltic volcanism) is produced to fill that gap. Abundant submarine volcanism means that there is a lot of very hot rock and molten lava at, or just beneath the ocean floor along mid-oceanic ridges. Black smokers are hydrothermal vent openings on the sea floor, located generally approximately 2 km below the water surface, that emit very hot water that has been heated up by the hot rocks. This superheated water (up to 400° C) is rich in dissolved minerals leached from the ocean floor. When the hot water is vented into the ocean, it suddenly cools and the dissolved minerals precipitate, appearing like a cloud of black smoke. When the superheated water comes in contact with the cold ocean water, it cools and sulfur-bearing minerals crystallize or precipitate out of solution and produce the solid structure that is called a “Black Smoker”.
The real surprise was that the sites of Black Smokers were also home to thriving communities of life. The basis for that life are extremophiles that convert the heat, methane, and sulfur compounds provided by black smokers into energy through a process called chemosynthesis.
This discovery had significant implications to theories on where life on Earth may have started. Prior to that discovery, the scientific consensus was that life was originally powered by sunlight. The most likely location for life to begin was thought to be some kind of shallow water setting. But there were known problems with this idea. The early Earth was not a particularly stable setting as it would have been subject to frequent impacts. But a deep oceanic setting would have been a more protected environment. Hence, it has been suggested that deep sea vents were the site where life began. There is, in fact phylogenetic evidence, which, as stated above, we will not discuss, that suggests that thermophiles are in fact the last common ancestor of Archaea, Eukaryotes and Bacteria.
If you like the Science Guy (Bill Nye), you'll enjoy this 5 min clip discussing what we have outlined above. If you don't, maybe the mention of giant red-blooded worms will peak your interest.
Please note that we still don’t know with certainty and there are a number of Abiogenesis or “Origin of life” theories, but the deep sea vent hypothesis is now favoured by many. The liquid oceans of the satellites of the outer planets are prime locations for the potential existence of these kinds of extremophiles.SaveSave