From space, Saturn’s moon Enceladus might not seem habitable. Its cold surface is covered with a thick layer of fresh ice and features active volcanoes that eject craters and ice crystals. But scientists believe that beneath its frozen exterior is a sea of salty liquid. Energy from geothermal vents on the seafloor and a little bit of the right material could provide a place for life to evolve and settle. A new analysis of data from NASA’s Cassini mission reveals that, in theory, the moon has all the chemicals that life needs to survive.
water column spouting from Enceladus contains phosphorusaccording to a study published Wednesday in the journal Nature By an international team of researchers. They discovered Lynn by examining data collected by. Cassini Findings from a 13-year survey of the Saturn system. This is the first time that this essential element for life has been found in an ocean other than Earth.
“Phosphorus in its phosphate form is essential for all life on Earth,” study authors say Frank Postberg, planetary scientist at the Free University of Berlin. “Life as we know it wouldn’t exist without phosphates, and there’s no reason to think that even if potential life forms exist on Enceladus, they should be radically different from those on Earth.” .”
This discovery provides no evidence of alien presence on Enceladus. But the presence of phosphorus removes a major obstacle to any life that might evolve there. Postberg said previous research had suggested that Enceladus’ oceans might not contain phosphorus. The discovery changes how scientists have to think about the moon’s potential habitability and will guide studies of other icy moons with subsurface oceans, such as Jupiter’s moon Europa. there is a possibility.
[Related: NASA hopes its snake robot can search for alien life on Saturn’s moon Enceladus]
Cassini was launched in 1997 and arrived at Saturn in 2004. It remained on Saturn to study the ring gas giant and its moons until NASA ordered the rover to self-destruct by plunging into Saturn’s atmosphere at the end of her 2017 mission. During that mission, Cassini passed Enceladus several times, including his 2005 flyby that the rover reached. Discover plumes of icy material, captured the crystals ejected by the Moon. These plumes likely represent ocean water escaping into space, and planetary scientists believe that beneath the moon’s ice shell lies a global ocean of liquid water.
Postberg said researchers were looking at ice grain data during the Cassini mission, primarily looking for inorganic and organic compounds. However, in 2017 his research team received a grant from the European Research Council to investigate ice grain data for Enceladus at a larger scale. After four years of research, they discovered that phosphorus is in the salt form, phosphate.
Humans know that phosphorus must be present, thus stating that phosphorus is one of the six essential elements of life. morgan cable, He was an astrobiologist at NASA’s Jet Propulsion Laboratory, but was not involved in the research. His other five major elements are carbon, hydrogen, nitrogen, sulfur and oxygen. “Combining these elements into different organic molecules allows the biochemistry, or specific reactions, that cells need to stay alive,” says Cable.
Phosphates are particularly important as they are the backbone of the DNA molecule. It is also an important component of adenosine triphosphate (ATP), which provides energy for cell membranes and cell activity. “This is the energy carrier molecule and the energy currency for all known life,” says Cable. This arrangement is likely to be used for any life occurring on Enceladus, although perhaps in different combinations with other elements.
[Related: Here’s why Saturn’s ‘ocean moon’ is constantly spewing liquid into space]
According to Enceladus, the oceans of Enceladus are somewhat chemically different from Earth. Mikhail Zolotova planetary geochemist at Arizona State University, Research commentary Also posted on Wednesday Nature. “In our oceans, it’s mostly sodium chloride and other salts,” says Zolotov. In Enceladus, the salt is baking soda. Same as in the kitchen.
Many of Earth’s marine life would have had no trouble surviving in Enceladus’ waters, Cable said. But if life did, or has, evolved on an icy moon, it’s likely to be microbes, not the extraterrestrial equivalents of fish and whales. It has more to do with the energy available to life there than with the chemistry of the Encerade Sea.
“On Earth, the main source of energy used by all life, directly or indirectly, is sunlight. It is either directly photosynthesizing, eating the plants that do it, or eating the animals that eat the plants. Either,” she says. Since sunlight cannot reach the water through the lunar ice shell, the energy likely comes from a geothermal source. ice crystal structure caught in Cassini This suggests that the particles formed near geothermal vents on the ocean floor, near where the water meets the rocky interior.
“If you look at the energy you get from the sun and the net energy you get from the sun, it’s an order of magnitude less,” says Cable. “That means you can either support a community of microbial cells or sustain a smaller number of microbes that are more energy-hungry.” A whale sings a sad sad song all by itself,” she says with a laugh. “How horrifying is that?”
Finding out if there is any life on Enceladus would require another mission to the moon. While nothing is moving fast, the influential Space Biology Decade recommends NASA’s flagship mission to Enceladus within the next decade.
But two missions are headed toward a world similar to Enceladus. The European Space Agency’s Jupiter Icy Moon Explorer (JUICE) mission launched in April and is scheduled to arrive at Jupiter in 2031 to study the gas giant and its icy moons Ganymede, Callisto and Europa. NASA plans to launch the Europa Clipper program in 2024 and reach the moon by 2030. A recent discovery of Enceladus offers a tantalizing glimpse into what lies beneath the surface of other ices. All three moons are believed to have oceans beneath them. , that too.