A dramatic plume sprays water ice and vapor from the south polar region of Saturn's moon Enceladus. Cassini's fist hint of this plume came during the spacecraft's first close flyby of the icy moon on February 17, 2005. (Credits: NASA/JPL/Space Science Institute.)
It was almost as if Enceladus, one of Saturn’s 62 moons, was waiting for the spacecraft Cassini to spray its organic material which may turn out to be the clearest evidence yet of life elsewhere in our solar system. As I tweeted, Europa, suck on that.
There is always the danger of premature elation when it comes to such discoveries but while it lasts that elation is quite joyous even if it is not real. As is my habit, I read the scientific paper published in Nature in support of the Enceladus finding and understood barely one percent and that too by some intelligent inference. I studied physics and chemistry at graduate level, which has given me at least some lexical familiarity with technical terms. However, that is woefully adequate to make sense of the pure science of the paper.
NASA explains it best in its official release:
Data from NASA's Cassini spacecraft reveal complex organic molecules originating from Saturn’s icy moon Enceladus, strengthening the idea that this ocean world hosts conditions suitable for life. Research results show much larger, heavier molecules than ever before.
Powerful hydrothermal vents mix up material from the moon’s water-filled, porous core with water from the moon’s massive subsurface ocean – and it is released into space, in the form of water vapor and ice grains. A team led by Frank Postberg and Nozair Khawaja of the University of Heidelberg, Germany, continues to examine the makeup of the ejected ice and has recently identified fragments of large, complex organic molecules.
Previously, Cassini had detected small, relatively common organic molecules at Enceladus that were much smaller. Complex molecules comprising hundreds of atoms are rare beyond Earth. The presence of the large complex molecules, along with liquid water and hydrothermal activity, bolsters the hypothesis that the ocean of Enceladus may be a habitable environment for life."
Potsberg from the University of Heidelberg, Germany, and the lead author of the paper, has been quoted as saying by National Geographic, “We cannot decide this hundred-million-dollar question, but it certainly shows that something is going on there, that complex organic chemistry is happening and that we can probe it from space,” says Frank Postberg of the University of Heidelberg, lead author on the paper describing the results today in the journal Nature.
“The moon freely delivers its organic inventory at high concentrations to the Cassini spacecraft. That’s just an amazing finding.”
The finding does not necessarily mean that these organic chemicals made the leap to self-replicating organisms, which we understand as life. However, as evidence of life goes this appears to be the strongest yet. The Independent newspaper of Britain quoted Dr. Christopher Glein, a space scientist specializing in extraterrestrial chemical oceanography but and one of the authors of the research paper, as saying that based on this finding Enceladus is the only body so far other than Earth which “simultaneously satisfy all of the basic requirements for life as we know it”.
Some of you might remember that Cassini, which explored the Saturn system for some 13 years, was deliberately crashed into Saturn on September 15, 2017. But that was after it had sent back an enormous amount of data about the Saturn system,including information about the organics bubbling up from Enceladus’ hydrothermal vents on the floor of its ocean and eventually shot up into space. (See the photograph).
The probe also studied particles in Saturn’s E ring which is the farthest from the planet. A NASA backgrounder describes the E ring thus: “The E-ring is centered on Saturn's moon Enceladus. (Enceladus is about 4 Saturn radii from Saturn, if you want to locate it on your ring map.) The densest part of the E ring is right at Enceladus' orbit, which suggests that Enceladus is the source of the particles in the E ring. In fact, we've just recently discovered that that's what's happening: there is a geyser at the south pole of Enceladus that is shooting a jet of water particles into space, and it's particles from this geyser that has created the E-ring.” That description should explain why Cassini studied that ring as well.
There is nothing to suggest so far that the Enceladus discovery could signal large complex organisms comparable to ocean creatures on Earth swimming around there. There is, in fact, nothing to suggest life as we have come know it in its everyday sense. For instance, there is no Supreme Court on Enceladus where an ageing justice has just announced his retirement. Or for that matter that is also no football world cup. And there is certainly no Donald Trump on Enceladus.
I always make this broader point when I post such findings. As a professional class of people scientists and engineers are perhaps the only one making a real contribution to human life. They may be wrong in their inferences sometimes but they never reach their conclusions before an intensive process. Read the paper about the Enceladus finding here if you don’t believe me.