Detecting life on Enceladus requires 100 flybys through geysers
Keituber.com – Detecting life on Saturn’s icy moon Enceladus may be possible without landing on the moon, new research suggests. But it won’t be easy.
A team of researchers has found more than 100 flybys searching through the geyser plume. Enceladus By orbiting spacecraft to capture cell signals – a vital indicator to confirm the existence of life. This discovery could help design future space missions. Saturn And Enceladus and to facilitate scientific answers, especially if life is not found.
Detecting life on Enceladus requires 100 flybys through geysers
In 2015, NASA Cassini spacecraft He flew Geysers spewing from the surface of Enceladus. Data from several flybys indicate that the plume contains abundant dihydrogen (H2), not unlike that found on Earth, suggesting the presence of hydrothermal air on the lunar seafloor. The data reflects a large amount of carbon dioxide and Methane (CH4), both of which tell us that methane-based life evolved. Methanogens It may exist around hydrothermal vents on Enceladus.
Now researchers have made a model of the moon Hydrothermal vents To better understand how many cells enter the lunar surface to estimate the mass of such methanogenic ecosystems and ultimately leave the lunar surface.
100 flybys through geysers
“We were surprised to find that the estimated number of cells in Enceladus’ global ocean is only the biomass of a single whale,” said Antonin Afholler, a postdoctoral research associate at the University of Arizona and lead author of the study. press release (Opens in a new tab).
By estimating cell densities, the team found that the moon’s life-supporting region, or biosphere around hydrothermal vents, could be very small — less than 10 tons of carbon, which is less than the surrounding biosphere. Earth’s hydrothermal vents.
what are geysers
Enceladus’ plume seen in Cassini spacecraft images may contain underwater microbes. (Image credit: NASA/JPL–Caltech/Space Science Institute)
Definitive evidence of living cells captured on an alien world may remain unknown for generations. Antonin Affholder, lead author of the study
However, according to this new research, sufficient amounts of cells and organic material from methanogens are ingested. of SpottedAt least some will increase the chance of being captured by a visiting spacecraft.
what 100 flybys
“Enceladus’ biosphere may be very small,” Afholder said. “And our models indicate that it will be productive enough to feed enough organic molecules or cells to be carried by instruments on a future spacecraft.”
If hydrothermal vents on Enceladus’ seafloor harbor methanogens, these organisms would live near the vents. They do it on earth. The warm water released at such vents mixes with methanogenic cells and escapes until it reaches the moon, where at least 100 pb are actively erupted through cracks in the icy crust.
A deep-sea inlet in the Marianas region on Earth. (Image credit: Image courtesy of 2014 Submarine – Ironman, NOAA/PMEL, NSF.)
Similar vents may exist on Enceladus’ seafloor. On Earth, the hydrothermal vent environment supports the creation and growth of yeti crabs, tubeworms, and a specific species of shrimp with light-sensing cells (or eyes) on their backs. Given the uniqueness and diversity of the deep-sea ecosystems surrounding Earth’s hydrothermal vents, similar vents on Enceladus are potential places to look for extraterrestrial life.
Assuming that most of the methane comes from methanogens living in the lunar ocean, researchers say it’s possible to sample a cell from an orbiting spacecraft — if a cell survives the trip to the surface.
According to previous studies, 93% of plum material He falls back (Opens in a new tab) On the lunar surface, sampling via flybys is a time-consuming challenge. Moreover, as the plume moves upward and outward into space, not all cells that enter the plume survive the pressure. Previous experiments showed that 94% of cells were destroyed by depression.
Perhaps a more pressing challenge is the presence of nonliving substances called organic abiotic amorphous materials. The researchers note in the new study that abiotic amorphs have the same signatures as living cells, leading to a higher risk of false positives.
To overcome these challenges and maximize the chances of (real) cell sampling, Afholder’s team confirmed that at least 0.1 ml of the plume should be sampled, which they say is equivalent to 100 spacecraft.
While 100 flight paths sounds like a lot, the current plan for NASA’s flagship mission, Enceladus Orbilander, shows that such an effort is achievable. After orbiting the moon for a year and a half, the Orbilander could have 1,000 flybys in its pipeline. These samples will be crucial data points in the hunt for life – or even its absence – on the Moon.
“True evidence of living organisms captured on alien worlds may not be seen for many generations,” the researcher said. “Until then, we cannot avoid the fact The presence of life on Enceladus It might be the best we can do.”
The study was described by Paper (Opens in a new tab) Published December 13 in the Journal of Planetary Science.
