All posts tagged: subsurface ocean

Scientists recreate Enceladus’s ocean and watch Earth microbes thrive

Scientists recreate Enceladus’s ocean and watch Earth microbes thrive

Published by Jenni Sidey

Laboratory experiments show that a methane-producing archaeon from Earth can grow under simulated Enceladus seafloor conditions at pH values as high as 11, far beyond its previously reported natural range. Water-rock reactions in the experiment produced hydrogen that fueled microbial metabolism, while Enceladus-like concentrations of dissolved inorganic carbon helped the organisms overcome the severe shortage of available carbon dioxide. The results do not show that life exists on Saturn’s moon, but they broaden the conditions considered potentially habitable and strengthen the case for future missions that directly sample Enceladus’s ocean-derived plumes. Beneath the frozen surface of Saturn’s moon Enceladus lies an ocean unlike anything familiar on Earth. It is dark, highly alkaline and separated from space by kilometers of ice, yet its chemistry may be surprisingly accommodating to life. Laboratory experiments now show that an Earth microorganism can grow under conditions designed to reproduce parts of the moon’s hydrothermal seafloor. The microbe survived at pH values reaching 11, producing methane while drawing energy and carbon from reactions involving water, rock, hydrogen and dissolved carbonate. Researchers …

Saturn’s moon Enceladus offers new clues in the search for alien life

Saturn’s moon Enceladus offers new clues in the search for alien life

Published by Jenni Sidey

A new analysis suggests that droplets sprayed from its hidden ocean can separate dissolved chemicals as they freeze, concentrating different compounds into different microscopic regions. Those frozen droplets may then smash apart inside cracks in the ice, producing chemically distinct grains that erupt into space. The process means an individual grain may contain a much higher concentration of a particular substance than the ocean itself. If organic molecules or biological material behave similarly, traces of life could become concentrated into a small number of particles that future spacecraft could analyze directly. The study, published in Science Advances, combined measurements from NASA’s Cassini mission with laboratory freezing experiments, thermodynamic calculations and models of conditions inside Enceladus’s icy vents. Fabian Klenner is an assistant professor in the Department of Earth and Planetary Sciences at UC Riverside. (CREDIT: UCR/Stan Lim) “We show that each grain is not necessarily a tiny scoop of the ocean,” said Fabian Klenner of the University of California, Riverside. Instead, a grain may be a fragment of a much larger droplet whose chemistry changed …

New findings complicate the search for life beneath Europa’s ice

New findings complicate the search for life beneath Europa’s ice

Published by Jenni Sidey

Water trying to rise from Europa’s ocean would likely cool quickly and begin freezing inside cracks. Tiny ice crystals could build into slush and clog those pathways within hours. Shallow water, if detected, may have melted locally instead of coming from the deep ocean. Europa’s buried ocean may be one of the solar system’s most promising places to search for habitable conditions. Yet the icy moon’s surface may be far less connected to that ocean than scientists once hoped. A Rutgers-led study in Nature Astronomy examined whether liquid water can rise from Europa’s deep ocean through cracks in the ice. The simulations suggest that water may cool, form ice crystals and clog its route before reaching shallow depths. Europa’s surface features and conceptual model schematics. (CREDIT: Lujendra Ojha et al, Nature Astronomy) A frozen barrier above a restless ocean Europa’s global ocean may stay liquid because Jupiter’s gravity repeatedly squeezes and stretches the moon. That motion generates heat beneath the frozen exterior. Scientists have proposed that water could move upward through narrow fractures called dykes. …