(Photo: Wikimedia Commons/NASA / Jet Propulsion Lab-Caltech / SETI Institute)
Deep-sea hydrothermal vents could be signs of alien life.
Low-Temperature Hydrothermal Vents On Ocean Moons Could Be a Sign of Alien Life
Researchers from the University of California, Santa Cruz (UCSC) created a model proliferating low-temperature vents on Jupiter's moon Europa and Saturn's satellite Enceladus. Based on their simulations, low-temperature hydrothermal vents could survive in those areas.
Hydrothermal vents are a potential site for the emergence of life on Earth because they provide heat and chemical energy. Planetary scientists have postulated that hydrothermal vents beneath the ice on Jupiter's moons, such as Europa and Ganymede, as well as the Saturn satellite Enceladus, may contribute to the warming of these oceans and the initiation of life's biochemistry.
The issue is that volcanic activity-driven "black smokers"-vents with exceptionally high temperatures- have been the focus of modeling efforts. Although these extremely hot vents can draw energy from Earth's heated core, it is unclear whether they could endure long enough to establish the necessary conditions to support life because the icy moons lack hot cores.
Under Andrew Fisher's direction, a UCSC team modeled the spread of these types of low-temperature vents on Europa and Enceladus. Fisher's team based their simulations on the circulation system in the northwest Pacific Ocean, specifically the eastern flank of the Juan de Fuca Ridge, where cool seawater sinks and flows down into the rock in the seabed via extinct volcanic cavities called seamounts because there is a lack of information available about the oceans on these moons. Before rising up through another seamount, the water passes through the rock for roughly 30 miles (50 kilometers), heating up.
According to UC Santa Cruz researcher Kristin Dickerson, who is also a study team member, the water absorbs heat as it flows and emerges warmer and with a completely altered chemical composition.
By modifying characteristics like gravity, temperature, bedrock composition, and water circulation depth on Europa and Enceladus, the scientists were able to better simulate possible circumstances on the ocean moons.
It was discovered that relatively warm vents could be sustained under various circumstances on these moons, and the reduced gravity also permitted the vents to emit warmer temperatures. In addition, such moderate- to low-temperature vents might be sustained for billions of years due to the low efficiency of heat extraction from the moons' cores, which are assumed to be rather cool in the first place, given the low gravity.
"This study suggests that low-temperature - not too hot for life - hydrothermal systems could have been sustained on ocean worlds beyond Earth over timescales comparable to that required for life to take hold on Earth," Fisher said.
Aliens May Have Used Greenhouse Gases To Make Other Planets Habitable
Another study also pointed out the possibility of greenhouse gases being a sign of extraterrestrials. According to researchers, man-made gases can be indicators of terraformed planets.
The green gases that contribute to global warming can reportedly help aliens terraform planets or exoplanets to make them habitable. And since there are not many greenhouse gases like carbon dioxide, methane, nitrous oxide, and other synthetic chemicals, they must be artificially produced, which indicates technologically advanced intelligent living species. Thus, greenhouse gases can be considered technosignatures.
RELATED ARTICLE: NASA Astronaut Captures Rare Red Sprite Phenomenon From ISS [See Photo]
Check out more news and information on Space in Science Times.
