Polski
If you ever have the chance to go down to the bottom of the ocean, don’t miss it. […] It will change your mind forever – Kevin Peter Hand, 2022, Extraterrestrial Oceans.
I have been diving in Mexican caves for 15 years. I have seen herds numbering hundreds of dolphins and hammerhead sharks in the Galapagos, cosogons in Malapaska, herds of reef manta rays in Komodo and oceanic manta rays in Raja Ampat. I dived with scientists studying whale sharks in Djibouti. Over the years I have learned about the life of the reefs of the Coral Triangle: Indonesia, Malaysia and the Philippines… When asked about dreams, I always answer: to dive on Europe! Not in Europe — on Europe. Dreams need to be fulfilled, so I hope that someday someone – even if not me – will dive into the oceans of Jupiter’s moons. NASA scientists have been dreaming about this too, since the 1990s, since the Galileo mission. One of these dreamers recently wrote a book visualizing oceans on other worlds in the solar system.
Kevin Peter Hand is a planetologist and astrobiologist. He studied physics and psychology. Eventually, however, he became an engineer and was employed by NASA. As a doctoral student, he collected samples of marine life from hydrothermal vents on the Atlantic and Pacific seabeds in missions funded by James Cameron [1]. Not without adventures: We are stuck at the bottom. The battery was running low. We were running out of air. In no way could we contact either the other team or the crew of the boat hovering somewhere 3 kilometers above us.
In 2007. defended his doctoral dissertation on potential life in Europa’s oceans [2]. Extraterrestrial Oce ans : The Search for Life in the Depths of Space is the Polish translation of his book Alien Oceans: The Search for Life in the Depths of Space, which was published in 2020. [3]. This is a fascinating journey through the solar system with an aquanaut and astrobiologist.
Extraterrestrial oceans – something more than the imagination of science fiction authors
How do we know about the oceans on the moons of Jupiter, Saturn and other celestial bodies? They cannot be seen even through the most powerful telescopes, although Ganymede and Titan are, after all, larger than Mercury, and Callisto is almost the same size. When Galileo Galilei in 1610. was discovering Jupiter’s moons, it would never have crossed his mind that the interiors of as many as three of them might conceal oceans. When Arthur C. Clarke wrote in 1968. His first odyssey: 2001: A Space Odyssey, placed the action on Iapetus, one of Saturn’s moons. Stanley Kubrick, however, moved the film adaptation of the novel to Europa, a moon of Jupiter.
A lucky guess or a hunch? At the time, no one outside Mother-Earth had yet dreamed of subcutaneous oceans. The first imagination-busting images of Jupiter’s Galilean moons were sent by the legendary Voyager 1 and 2 probes. Along with the photographs came surprising data… [4], Hand leads us step by step, uncovering more secrets against the background of NASA’s space missions.
Moons inconsistent with model
The Galileo probe’s ill-fated mission found that the Galilean moons have magnetic fields. This was unexpected, since even Mars doesn’t have one. It was therefore believed that bodies smaller than the Earth simply could not have magnetic fields. However, when exploring the Universe, we very often find out that it is quite different from what we previously imagined….
Oceanic solution to planetary puzzle
Each moon has a different story. In the case of Europa, the explanation turned out to be a field induced in a liquid conductor – an ocean a hundred kilometers deep hidden under at least a few kilometers of ice. During the writing of the second odyssey in 1982, filmed by Peter Hyams two years later, as a 2010: The year we made contact, the scientific world was already dreaming of extraterrestrial life hidden in the sub-ice oceans of Europe. The mysterious subsurface ocean was soon joined by bodies of water hidden under the ice of other worlds in the system.
The oceans of the solar system
I like to think that the yellows, reds and browns on Europa’s surface testify to the life going on in the ocean beneath it, evolving over the eons of its tidal dance around Jupiter. […] I love to imagine that the other side of the ice – the one that meets the ocean of liquid water – is teeming with microorganisms and perhaps more complex creatures as well, creatures burrowing into the ice to draw from it oxygen and other compounds created by radiation somewhere high above – Kevin Peter Hand, 2022, Extraterrestrial Oceans.
Europa, Ganymede, Callisto, Titan, Enceladus and Triton – moons of the gas giant planets: Jupiter, Saturn and Neptune, and even Pluto, relegated to the status of a dwarf planet, hide abyssal oceans beneath their ice-covered surfaces, where there may be up to twenty times more salt water than we have on Earth. The ocean on Ganymede alone has ten times as much liquid water as Earth. And where there is water, after all, there may be life… Especially on Europa, Titan and Enceladus, where, as Hand points out, there are the best conditions for the emergence of life most similar to what we have on Earth.
Hand writes passionately about worlds he has never been to, as if he has known them for years. And in its own way it knows. We have been discussing the icy moons of Jupiter, Saturn and Neptune and the oceans hidden beneath their surfaces since the Voyagers and Galileo probes flew by. The Cassini probe mission has provided data on Enceladus and Titan – Saturn’s moons that also hide oceanic depths. The last of Earth’s spacecraft to fly past the Galilean moons was New Horizons, on its way to Pluto in 2007. performed a gravitational assist around Jupiter [5]. Pluto also appeared to hide an oceanic secret. If our solar system is so full of them, how many such oceans are hiding globs of other worlds in the Galaxy!
Hydrothermal chimneys – earth analogy
Two alternative theories regarding the origin of life revolve around the shallow floodplains of the early Earth’s seas, where a primordial soup may have formed [6], or hydrothermal vents located deep on the ocean floor. On Europa, Enceladus, Ganymede or Pluto we have no such choice. Astrobiologists thus see a chance for the emergence of life on distant globes thanks to the specific conditions that also exist in the depths of Earth’s oceans.
In places like the Lost City on the Mid-Atlantic Ridge with its serpentinization response [7]. They point to terrestrial organisms that feed through chemosynthesis, such as the scaly-footed snail that lives in chimneys and the riffles there [8].
In the article, I used, among other things. From the works:
[1] Hand explored the Mid-Atlantic and East Pacific ridges as part of the mission. This was captured in Cameron’s documentary film Aliens of the Deep, shot in IMAX 3D formations. James Cameron March 26, 2012. lowered himself to the bottom of the Challenger Deep in the Mariana Trench aboard the bathyscaphe “Deepsea Challenger.”
[2] Hand’s dissertation is summarized in an article in Nature 2009: https://www.nature.com/articles/457384a.
[3] Princeton University Press: https://press.princeton.edu/books/hardcover/9780691179513/alien-oceans.
[4] The first though not the best images of Ganymede and Io were sent by the probes Pioneer 10 (1973) and Pioneer 11 (1974). Voyager overflights near the Galilean moons took place at the end of the same decade.
[5] Gravity assist is a way to achieve greater speed. The New Horizons probe has delivered, among other things. photos of the eruption of the Tvashtar Paterae volcanoes on Io, Jupiter’s moon, which is the most volcanically active body in the solar system.
[6] Harold Clayton Urey (1893-1981), discoverer of deuterium (Nobel Prize in 1934) and one of the builders of the atomic bomb, proved in 1952, along with his master’s student Stanley Miller, that organic compounds, including amino acids, could be formed from inorganic substances such as methane and ammonia by lightning. The Miller-Urey experiment fulfilled the predictions of J.B.S. Haldane and Alexander Oparin.
[7] Serpentinization occurs when water comes into contact with peridotite rock of the Earth’s mantle, transforming the olivine or pyroxene in it into serpentine minerals such as chrysotile, lysardite or antigorite: Nills G. Holm et al. (2015) Serpentinization and the Formation of H2 and CH4 on Celestial Bodies (Planets, Moons, Comets). “Astrobiology” 15(7):587-600. https://doi.org/10.1089/ast.2014.1188.
[8] Discovered in 1977. at the bottom of the Galapagos Trench by geologist Jack Corliss from aboard the Alvin bathyscaphe, the thermophilic polychaete Riftia pachyptila has the form of a chitinous tube from which a red plume emerges, serving to draw hydrogen sulfide, carbon dioxide and oxygen from the water. The specific hemoglobin of riftia targets hydrogen sulfide, from which its endosymbiotic bacteria then obtain energy by chemosynthesis; A.J. Arp (2001) Hydrothermal Vent Fauna, Physiology of*, Encyclopedia of Ocean Sciences (2nd Ed.), Academic Press, pp. 159-163 https://doi.org/10.1016/B978-012374473-9.00106-5.
