Mythologies of the Solar System: Part Three

The names of the moons, planets and of course the Sun itself are not just household names un-associated with anything but these celestial bodies, but bodies usually named after selected characters from ancient Greek and Roman mythology. There are tales to be told about them; some fleshing out to do. These are just a few of the highlights.

The planets of the solar system are named after gods and goddesses and are known by their Roman, not Greek names. Here I’ll put the Greek equivalents in brackets afterwards. The satellites of these planets for the most part tend to be the Greek names associated in one form or another with the parent body or the god/goddess in question. Moons (and major asteroids) are identified with an asterisk.

Continued from yesterday’s blog…

MYTHOLOGY AND THE OUTER SOLAR SYSTEM

SATURN (Cronus) was one of those first generation Titans, offspring of Gaia and her son Uranus. He mated with Rhea, and produced from that union the original half-dozen gods and goddesses that would eventually become the Olympians. But the transition from Saturn’s offspring to become the rulers of Mount Olympus was an epic that could just about out-epic anything Hollywood has ever done. Saturn is known for two things in particular – castrating his daddy and snacking on his kids - Yum, yum. 

*Dione is a very obscure goddess who may have been a Titan or a Nereid or an Oceanid. Her name seems to be a feminine form of Zeus, and that brings in the alternative version of the origin of Aphrodite – a traditional birth via the union of randy Zeus and Dione (whoever she was). At least she’s now immortalized as a satellite of Saturn.

*Enceladus was one of the Gigantes. The Gigantes were offspring of Gaia, fertilized by the blood/semen of her son and lover Uranus who was ultimately castrated by Cronus (a son of Gaia and Uranus back when he had his private parts intact). In the Gigantomachia (the battle between the Olympian gods and the giants), Athena deposited Enceladus under Mount Etna and the fire and brimstone breath of Enceladus accounts for that volcano’s well, fire and brimstone. This is another abode thought as a possible site where alien life forms might one day be discovered.

*Hyperion was a Titan god, born of Gaia (Gaea) and her son, Uranus. He would become an early god of the Sun.

*Iapetus was another Titan god, born of Gaia (Gaea) and her son, Uranus. He would become the father of Prometheus, who ultimately is remembered for stealing fire from the gods and giving it to mankind.

*Janus was the Roman god of beginnings, doorways, entrances, gateways, etc. and is depicted with two faces, one each facing forward (to the future) and the other backward (to the past). January, the beginning, is named after him.

*Mimas, like Enceladus, was one of the Gigantes of Greek mythologies. Like the other giant sons of Gaia and Uranus, Mimas had serpents for legs and was born fully armored. Mimas was slain by Hephaestus during the war against the Olympians by a volley of molten iron.

*Phoebe was a Titan goddess, born of Gaia (Gaea) and her son, Uranus. Phoebe is identified as an early moon goddess. In another context, the goddess Artemis sometimes was associated with an alias of Phoebe. Finally, Helen of Troy had a half-sister Phoebe.

*Rhea was another Titan goddess, born of Gaia (Gaea) and her son, Uranus. She married Cronus (Saturn) and from that union was born what ultimately became the original half-dozen Olympian gods and goddesses. Cronus, out to eliminate potential future rivals, swallowed the first five of these kids, but Rhea tricked him when it came to the sixth and last, Zeus. She spirited Zeus away to Crete to be raised, and tricked Cronus into swallowing a stone disguised as the baby Zeus.

*Tethys was yet another Titan goddess, born of Gaia (Gaea) and her son, Uranus who would become the most ancient goddess of the sea.

*Titan is the largest moon of Saturn, a moon of interest to astrobiologists, and the only natural satellite to have an extensive atmosphere. In fact, Titan is larger than the planet Mercury and way lager than our own satellite, Luna. The mythology connection is that the original dozen Titans (some of which are named satellites of Saturn) were one of a set of offspring between Gaia and Uranus. Among the second generation of Titans are several household names like Atlas and Prometheus. They were overthrown in the Titanomachy (The War of the Titans) by Zeus and his fellow Olympians. 

URANUS (alternative spelling Ouranos) was the original sky god, the son, via parthenogenesis, of Gaea (Gaia) who shacked up with mum to produce all manner of deities, including monstrous ones. He’s known for having his privates sliced off by one of their Titan offspring, Saturn (Cronus). Saturn in turn got done like a dinner by one of his offspring, Jupiter (Zeus) but that’s another story.

*Ariel, Miranda, Oberon, Titania and Umbriel, the five major moons of Uranus, were named or chosen from the names of characters from the works of Shakespeare and Alexander Pope and thus, unfortunately, have near bugger-all to do with traditional Greek and Roman mythology. Bummer, as that spoils some potentially good stories relating back to and involving the parent god, Uranus.  

NEPTUNE (Poseidon) was the god of the sea, one of the original half-dozen Olympian gods and goddesses, brother to Zeus, Hades, Hera, Hestia and Demeter. All of Neptune’s known 13 satellites are named for Green and Roman water deities or groups of minor water gods. The major two are Nereid and Triton.

*Nereid – the Nereids (plural) were nymphs of the sea, the 50 daughters of the Mediterranean Sea god Nereus. Among the famous of the Nereids – goddess all – were Thetis (mother of Achilles), Galatea and Amphitrite (who married Poseidon). 

*Triton was another sea god, a son of Poseidon and the Nereid goddess Amphitrite, a nymph of the sea who became Queen of the Sea when she wed Poseidon. The typical depiction of Triton is that of a merman – human head and torso; one or two fishy (or maybe dolphin) tails. He too has a trident and a conch shell which when blown can calm the stormy waves. Like father, like son, Triton also had a bit of an eye for the ladies, especially beach-babes. Triton favors in a positive light for assisting Jason and the Argonauts in their saga. 

PLUTO (Hades) was god of the underworld. In the Greek version, Hades (the god) administered Hades (the underworld), so the name of the ruler and the place ruled were one and the same. Within recent times, Pluto was officially downgraded from planet to dwarf planet status, which made a lot of traditionalists very unhappy.

*Charon was the son of Erebus (the god of underground darkness) and Nyx (goddess of night), who played the role of the ferryman who rowed the newly deceased across the River Styx to Hades, the underworld. As a reward, or a fare, he got a coin in payment – no coin, no crossing. The parentage and place of employment are ideal for a satellite so far out from the Sun.

*Hydra (discovered in 2005) was named after that famed beastie slain by Hercules as one of his dozen labors in Greco-Roman mythology. Hydra was one of numerous monstrous offspring from Typhon and Echidna, themselves monsters. 

*Nix (a deliberate alternative spelling of Nyx) was a Greek goddess of night, one of the original deities conceived from the original state of the universe, Chaos. Nyx was the mother of Charon. Like Hydra, Nix the satellite was discovered in 2005.

ERIS is another dwarf planet, a trans-Neptunian object even larger that Pluto discovered in 2005. In fact it’s the most massive of all dwarf ‘planets’ in our solar system, even though it’s three times farther removed from the Sun than Pluto. Eris is a Greek goddess, the personification of strife and discord.

*Dysnomia in mythology is the daughter of the goddess Eris.   

NEMESIS (Fortuna was the Roman counterpart) was the asexual product of the goddess Nyx (night) and she was the goddess of retribution and agent of vengeance. Originally she was just one who dispensed fortune or luck without predetermined rewards or punishments, but morphed into a goddess of justice. The ‘Wheel of Fortune’ is thus associated with her. The celestial Nemesis is a hypothetical dwarf star binary companion to our Sun, a faint stellar object that has an extreme elliptical orbit that beings it close to the solar system once every 26 million years, which when extrapolated backwards, was useful in explaining periodic mass extinctions on Earth. Alas, all searches for this dwarf companion star have turned up negative, and the hypothesis is pretty much in scientific limbo today. 

Mythologies of the Solar System: Part Two

The names of the moons, planets and of course the Sun itself are not just household names unassociated with anything but these celestial bodies, but bodies usually named after selected characters from ancient Greek and Roman mythology. There are tales to be told about them; some fleshing out to do. These are just a few of the highlights.

The planets of the solar system are named after gods and goddesses and are known by their Roman, not Greek names. Here I’ll put the Greek equivalents in brackets afterwards. The satellites of these planets for the most part tend to be the Greek names associated in one form or another with the parent body or the god/goddess in question. Moons (and major asteroids) are identified with an asterisk.

Continued from yesterday’s blog…

MYTHOLOGY AND THE OUTER SOLAR SYSTEM

JUPITER (Zeus) was king of the mountain – Mount Olympus that is. He, after a series of ‘wars in heaven’ (with the Titans) and on earth (with the Giants) and finally with the daddy of all monsters, Typhon, claimed the right to be worshiped as King of the Gods, by all lesser gods and goddesses, demigods and demigoddesses, as well as all of the great unwashed – the mortals comprising humanity. Apart from being fast on the draw with his trademark thunderbolts, he’s most noted for being even faster on the draw with his private parts. No Mounties or bounty hunters ever perused their quarry better or with more determination than our always horny Jupiter/Zeus, as we shall see immediately below (though with over five dozen satellites, only a few can be entered into in this short essay).

*Amalthea: Jupiter (Zeus) as a young infant, was spirited and hidden away in Crete by his mother, Rhea from his daddy, Saturn (Cronus) because daddy didn’t want any sons of his eventually growing up and challenging him for supreme power. Saturn thus kept them out of his harms way by swallowing them. Rhea saved the last (Jupiter) by trickery. Anyway, young Jupiter was reared and looked after by local nymphs on Crete, especially by Amalthea. She’s also known for having a horn, the ‘Horn of Plenty’ a cornucopia that provided limitless food and drink for whoever possessed it.  

*Ananke, the goddess of inevitability and personification of destiny, necessity and fate was the mother of the Moirai by Zeus. The Moirai, also known as The Fates, were the trio that spun the thread of life of mortals from birth to death and thus controlled everyone’s destiny. Even Zeus was powerless against their will.

*Callisto was the daughter of the King of Arcady, and she had the misfortune to have Zeus fall for her. Callisto was associated with the virgin goddess Artemis. When Zeus raped Callisto, she got in a family way (in mythology, every rape results in a pregnancy otherwise there’s no point to the rape in the first place). This rape ultimately produces a son, Arcas. Artemis, being the virgin, was livid and banished Callisto from any further association with her. Hera (Mrs. Zeus) in the meantime assumed Callisto was a willing partner to her wayward hubby and in revenge turned Callisto into a bear. Years later, Arcas, out hunting, ran across that bear and not realizing that it was mom, shot her dead. Zeus then placed Callisto into the zodiac as Ursa Major, the Great Bear (or the Big Dipper); Arcas ultimately got his place in the heavens too as the Little Bear (or the Little Dipper).

*Carme was the mother by Zeus (who else?) of the virginal huntress Britomartis, a Minoan or Cretan goddess. Carme assisted in the harvest of the grain.

*Elara was the mother of the giant, Tityos. Tityos was fathered by you know who – randy Zeus. Tityos met a bad end, killed on the behest of Hera by Artemis and Apollo, and forever tortured in Tartarus (a subdivision of Hades) by a couple of vultures who liked liver for breakfast, lunch and dinner. Fortunately for the vultures, Tityos’s liver kept regenerating so they never lacked for food.

*Europa was the daughter of a Phoenician king. Zeus got the hots for her and turned himself into a snow-white bull (gods can shape-shift; it’s one of their major superpowers and that’s no bull) and approached Europa in that form. Europa playfully climbs on the Zeus-as-bull’s back. Zeus-the-bull then dives into the sea with Europa on his back and swims out to Crete. Once there he reverts back into his ‘human’ form and they made mad passionate love together and in the fullness of time Europa gave birth to triplets, one of which she named Minos. Zeus, ever thoughtful, also gave her some other gifts as well for her troubles. Europa ultimately married the king of Crete. Ultimately her son, Minos, assumed or claimed the throne. That’s why Crete’s ancient civilization is called the Minoan society. Europa is the only person having an entire continent named after them – Europe. As an aside, Europa is one of the few celestial bodies of interest to those on the lookout for potential sites where extraterrestrial life might exist.

*Ganymede: Abductions by the gods are by no means unknown or uncommon. In Greek mythology, a young handsome lad was Ganymede. He was abducted by Zeus, shape-shifted in the form of an eagle. Zeus favored the ladies, goddesses, demigoddesses, even mortal women, but for a catamite change of pace now and again… Ganymede was rewarded for his services by eternal youth and immortality, eventually placed in the sky as the constellation Aquarius. His daddy (Tros) was also compensated with a gift of fine horses.

*Himalia was a nymph who bore a trio of sons to Zeus or of course the Roman equivalent, Jupiter.

*Io was the daughter of the first king of Argos (what’s it about kings and their daughters already – that plot device has reached its use by date). She of course caught the lustful eye of Zeus. Hera (Mrs. Zeus) got suspicious, so Zeus turned Io into a cow as a disguise. Hera (knowing full well what was afoot) of course assumed the cow was a gift for her from her hubby since he obviously had no use for a cow, so Zeus had no option but to agree that that of course was what he had intended all along. Hera then had the cow guarded by the multi-eyed giant Argus. Zeus, needing to get Io back, got Hermes (Mercury to the Romans) to kill Argus. Hera in revenge plagued Io-the-cow with a hornet. Finally a truce was called. Zeus promised to behave (pull the other one) and Io was reverted back to human form and reunited with her worried daddy – the king.  

*Leda was of course the daughter of a king, and in turn married a king, in this case a king of Sparta. Zeus, of course, took a shine to Leda, and took the form of a swan and flew into Leda’s arms seeking ‘protection’ from another predatory bird – that’s his story and he’s sticking to it. Anyway, somehow or other (Zeus may have turned her into a goose) this cuddle made Leda pregnant and from this pregnancy she gave birth – she laid an egg, obviously! The egg hatched and out popped beautiful Helen. Helen, later known as Helen of Troy, was the face that launched a thousand ships (and then some). This was Zeus’s contribution to the Trojan War. In another version, the egg was the union between Zeus and the goddess of revenge, Nemesis. They gave the egg to Leda to hatch and raise the offspring up as her own. Leda had another child by Zeus – one of a pair of twins actually, Castor (by Zeus) and Pollux (by her husband) but known as the ‘Boys of Zeus’ or the ‘Heavenly Twins’ who eventually sailed with Jason as part of the Argonaut crew. 

*Lysithea was the daughter of Oceanus (a Titan, product of Gaia and Uranus) and one of Zeus’s many, many lovers.

*Pasiphae was the wife of King Minos of Crete, who, via a rather strange mating arrangement gave birth to the Minotaur. The rather remote connection to Jupiter is that Jupiter’s brother, Neptune, was behind all of this. Neptune was offended because Minos didn’t offer up as a sacrifice to Neptune a favorite bull, so in retaliation, Neptune saw to it that Minos’s wife became infatuated with, and lusted after a bull, the offspring being that well known hybrid, the Minotaur. 

*Thyone was once known as Semele, a lover of Zeus, who produced as offspring Dionysus, the god of wine and all around fun times. When Semele died as a result of Zeus revealing to her his true appearance – all the result of Hera’s trickery - and went to Hades, Dionysus rescued her from the underworld and brought her to Olympus, made her into a goddess along with providing the change of name. 

To be continued…

Jovian Life: The Moons Versus the Planets: Part Three

In our solar system, the planets are divided between the inner terrestrial planets (Mercury, Venus, Mars and of course the Earth) and the outer gas giants, collectively called the Jovian planets (after Jupiter, but including Saturn, Uranus and Neptune), which along with their many moons form the Jovian system. Since it’s easier to look in our own planetary backyard neighbourhood first for alien life, there’s been much speculation about what pieces of solar system real estate, if any, might be suitable abodes for extraterrestrial life. While Mars has always been top-of-the-pops, a once heavily favoured Venus fell by the wayside a while back, only to be replaced with a few bits of real estate somewhat further out. It’s those “somewhat further out” bits of real estate that are now under-the-gun. While most speculation is on selected Jovian satellites, I put the accent on the parent bodies.

Continued from yesterday’s blog…

Uranus: CHON: Uranus is similar in atmospheric and chemical composition to Neptune (see below), but both are slightly different in their chemical composition than their larger gas giant sisters, Jupiter and Saturn. As such, astronomers sometimes place them in a separate category called the "ice giants" because these planets contain a lot of – wait for it – “ices” like water (the O in CHON), ammonia (the N in CHON), methane plus other hydrocarbons (your C and your H in CHON) that includes ethane, acetylene, methylacetylene, and diacetylene. In short, instead of say liquid water vapor, you have ice crystals. Uranus's atmosphere is however similar to the “gas giants” in having the majority of its stuff consists of hydrogen and helium, hence followed by methane (there’s some more of your C). Even more C is present in carbon dioxide and carbon monoxide which has been detected. While carbon consists of only about 3% of the composition of Uranus, that’s still vastly more carbon relative to the solar percentage, so Uranus has been enriched in carbon.

Uranus: Environment: Uranus (as well as Neptune), are often refereed to as the “ice giants” instead of the “gas giants” as noted above. One other distinction is that relative to Jupiter and Saturn, Uranus (and Neptune) are way smaller in volume. That apart, the “ice giants” are way more akin to the “gas giants” than to any of the Jovian moons or any of the terrestrial planets for that matter, both in terms of composition and in terms of relative volume. While pretty god-awful from a human’s perspective, some hardy microbes might love to call Uranus home.

Uranus: Mixing: Any lump of gas molecules, or molecules in a liquid, almost by definition, isn’t going to sit still, unlike say the molecules in a lump of rock. A puff of smoke emitted into Earth’s atmosphere gets dispersed; a drop of ink plonked into a bowl of water will equally get dispersed, or mixed in and throughout.  I’d expect nothing less in the non-solid soupy atmosphere of Uranus. In any event, wind speeds have been clocked at up to 900 km/hour – that’s pretty breezy!

Uranus: Energy: Uranus radiates just ever slightly more heat than it receives in the form of solar radiation. In case you think that makes Uranus frigid through-and-through, you’d be wrong. The interior core temperature still approaches over ten to twenty times the maximum temperature of your average home oven! So, while solar energy is just about zilch, energy percolating upwards nevertheless is present for utilization by the locals – if any. However, of all the four Jovian planets, Uranus is probably the least likely planet to have achieved the distinction of harbouring local (Uranian) life forms.

Neptune: CHON: Neptune’s atmosphere is mainly, as you’d expect one that consists mainly of hydrogen and helium, but with substantial amounts of water, ammonia and methane. CHON is present, as are various sulphide compounds.

Neptune: Environment: While the top of the atmosphere is very cold, as you’d expect being so far out from the Sun, the interior core is hot indeed – many thousands of degrees hot. Obviously, somewhere in-between, you’ll get a happy Goldilocks medium as far as biology is concerned.

Neptune: Mixing: Neptune has lots of varied weather and storm systems, all contributing to atmospheric mixing. The temperature differential between interior temperatures and the atmospheric ‘surface’ temperatures, like on Earth, will drive wind systems leading to mixing of the chemicals that make up the CHON-rich atmosphere

Neptune: Energy: Despite being farther away from the Sun than Uranus, Neptune radiates quite a bit more heat than it actually receives from Sol. In fact, slightly over two and a half times more heat. From the point of view of this analysis, the exact reason(s) aren’t overly relevant, just the fact that it does so. Of course being so very, very far away from the Sun there’s no chance in hell of photosynthesis; chemosynthesis is possible, even probable.

In conclusion, I suggest that the soupy atmospheres of the giant planets have all the fundamentals required not only for the origin of life, but long-term habitability for any biological organisms that have been and are being provided with appropriate CHON, a Goldilocks environment (at least in places), an energy supply, and mixing. The CHON box is ticked on all four Jovian planets. With respect to CHON, there are probably all sorts of way more complex organic molecules present in the four Jovian atmospheres but in such relatively small quantities that are dispersed widely and deeply so as to have escaped detection to date from our relatively faraway fly-by and orbiting probes. The habitable environment box on all four Jovian planets is also ticked; ditto the mixing box; and ditto the available energy supply box. You also have had over four and a half billion years for interesting biological happenings to have occurred. In addition, there’s a lot of volume in each of the Jovian planets for interesting stuff to happen in. The odds of things all coming and getting their act together in a small pond is small relative to a large ocean.

That all four Jovian planets have evolved life is problematical; that at least one has become a biological abode is much more certain, IMHO. Throw in one or more of their satellites like Europa and Enceladus that offer a liquid water ocean environment – well that’s a bonus. On top of all that, the Jovian planets have the highest gravities apart from the Sun. Now that means they suck in more than their fair share of other solar system debris – like comets and asteroids. Now comets and asteroids, the leftovers of that initial stuff out of which our solar system was made, also tend to be rich in CHON. No doubt they, via impacts with the Jovian planets, have contributed their CHON bit to the already potential suitability of those abodes as habitable abodes.

So what sort of Jovian life might we expect? On Planet Earth there is a sharp boundary between the atmosphere and the hydrosphere. On the four Jovian planets one just slowly merges into the other as one goes deeper and deeper. Terrestrial but airborne microbes, bacteria, germs, and other single-celled beasties, and their marine equivalents, like plankton and other unicellular critters, occupy both environments and are happy little campers. There’s no reason for there not to be Jovian equivalents that ‘swim’ and multiply in whatever region of the various four varieties of Jovian atmospheric ‘soups’ that have a comfortable, Goldilocks temperature regime. Of course that Goldilocks region could extend over hundreds of vertical kilometres in range. Some organisms might be better adapted to the thinner cooler upper regions; others to the murkier but warmer depths. Regardless, it gets dark fast so eyesight in the visible range of the electromagnetic spectrum might be problematical. Of course phosphoresce, not all that uncommon in marine life here on Earth, can’t be ruled out of course.    

If simple life forms originated and evolved on Jupiter, Saturn, Uranus and/or Neptune, then more complex and far larger ‘marine’ and ‘aerial’ life forms might be present too. Their trick, in order to stay in the Goldilocks zone, will be to have evolved the capability to maintain neutral buoyancy, but also to be able to rise if turbulence pushed them downwards towards greater heat; be able to sink if currents push them too high where chill factors come into prominence. So ‘gas bag’ floaters or ‘fish’ with ‘airbags’ might be possible Jovian alien life-forms. There’s no reason such critters couldn’t have developed a relatively sophisticated degree of intelligence. It’s possible to have intelligence without the means of developing technology as our whales and dolphins and even the humble octopus demonstrate.

The fly in the ointment is that our on-site investigation is going to prove to be an extremely daunting technological task, one that most certainly won’t happen in the next several decades – probably much longer. In the short term, the best bet is to use remote spectroscopic analysis of the atmospheric ‘surfaces’ or actual surfaces (in the case of the satellites) to identify biological signatures – compounds that just cannot be accounted for by non-biological processes. An example would be the pinkish-red areas on Europa noted above. 

Jovian Life: The Moons Versus the Planets: Part Two

In our solar system, the planets are divided between the inner terrestrial planets (Mercury, Venus, Mars and of course the Earth) and the outer gas giants, collectively called the Jovian planets (after Jupiter, but including Saturn, Uranus and Neptune), which along with their many moons form the Jovian system. Since it’s easier to look in our own planetary backyard neighbourhood first for alien life, there’s been much speculation about what pieces of solar system real estate, if any, might be suitable abodes for extraterrestrial life. While Mars has always been top-of-the-pops, a once heavily favoured Venus fell by the wayside a while back, only to be replaced with a few bits of real estate somewhat further out. It’s those “somewhat further out” bits of real estate that are now under-the-gun. While most speculation is on selected Jovian satellites, I put the accent on the parent bodies.

Continued from yesterday’s blog…

Now on to the major players! It’s time to introduce the main players, Jupiter, Saturn, Uranus and Neptune, and those four essentials: CHON, environment, mixing and energy. If there is life-as-we-know-it on these four planets, then we need CHON, we need a proper environment, we need mixing to bring essentials together at one time and place, and we need a source(s) of energy.

One clarification is in order first. Although the Jovian planets are usually called “gas giants”, that is a slight misnaming. While it’s true that relative to Mercury, Venus, Earth and Mars, the Jovian planets are indeed great big balls of gas, they still must have at their centre a solid rocky core, due to, if for no other reason, that over 4.5 billion years of their existence, asteroids, maybe even small planets, meteors, dust, and comets have all slammed into them. The rocky stuff, ultimately, must sink to the bottom forming a solid heavy element core. With that clarification made, let’s see what there is to be speculated upon. 

Jupiter: CHON: Jupiter, a gas giant, is composed mainly of molecular hydrogen (the H in CHON) and helium (much like the Sun’s composition and in roughly the same ratios). There are certainly ammonia (probably as ice crystals) and ammonia compounds (like ammonium hydrosulphide) in the atmosphere, adding nitrogen (the N in CHON) to the mix. Methane (which contains the C in CHON), as does the carbon contained in carbon dioxide and carbon monoxide are also present in the upper atmosphere. Water vapour (the O in CHON) is certainly present, even though in small proportions relative to hydrogen and helium. The colourful bands of latitude could easily be suggestive of complex, even organic chemistry involving not only CHON but sulphur and phosphorus and other trace elements. The upper atmosphere of Jupiter contains small amounts of simple hydrocarbons such as ethane and acetylene, which forms from methane under the influence of the Sun’s ultraviolet radiation and the highly charged particles incoming from the Jupiter’s magnetosphere.   

Jupiter: Environment: There’s no disputing that the cloud tops are bitterly cold; the deep interior is way too hot. But, that alone suggests that there will be a Goldilocks area in-between, probably extending vertically for hundreds of kilometres, and extending as well horizontally around the globe. That volume, given Jupiter’s size, comprises a lot of Goldilocks territory. 

Jupiter: Mixing: Since Jupiter has a very hot interior core and the top of the atmosphere is extremely cold, and since heat rises and cold descends, that alone suggests that mixing in Jupiter’s primarily gaseous/quasi-fluid body must take place. Quite apart from that, all one needs to do is view time-lapse photography of Jupiter’s upper atmosphere to see all the turbulent motion that takes place. A tranquil pond Jupiter isn’t.

Jupiter: Energy – Solar energy is highly unlikely to drive any Jovian biology because the atmosphere is very thick, and just like with our terrestrial oceans, things get very dark very quickly as one descends. However, chemical energy is a possibility, like that which drives terrestrial hydrothermal vent communities. Then there’s infrared (instead of visible) radiation. Jupiter radiates much more heat that it receives from the Sun, the heat being slowly radiated outward from Jupiter’s original quota of primordial heat energy largely stored in the core of the planet.  Jupiter is a fantastic place to visit if you’re fond of thunderstorms. Lightning really lights up the Jupiter’s skies. Lightning is a prime source of energy for driving chemical reactions. Translated, all up, Jupiter is awash with potentially useful energy sources to drive any local biology.

Saturn: CHON: The atmosphere of Saturn (which is what the mainly planet is – a ball of gas) consists of one hell of a lot of molecular hydrogen and some helium, a really skewed ratio relative to those elements found in the Sun, but that’s another story. However, it does explain why Saturn, if you could find a freshwater ‘pond’ large enough, would float in it! That aside, the atmosphere contains trace amounts of ammonia (there’s your nitrogen), acetylene, ethane and methane (and your carbon), plus phosphine - all have been detected. The upper atmosphere has clouds composed of ammonia crystals, while the lower atmospheric clouds appear to be composed of ammonium hydrosulfide and/or water (thus some oxygen).

Saturn: Environment: The same discussion that applies to Jupiter applies to Saturn, although because Saturn is a smaller planet (albeit massive relative to Earth) the habitable volume of Saturn’s quasi-liquid atmosphere will be somewhat less.

Saturn: Mixing: Saturn also has that hot interior, cold exterior dichotomy that exists in this gaseous/fluid planetary ball. It’s akin to the convection that occurs when you heat water on your stove. Hot water rises; cooler water descends. And while not as dramatic as time-lapse films of Jupiter’s atmosphere, it’s also obvious that Saturn’s visual ‘surface’ is anything but tranquil. In fact the winds on Saturn are among the highest of any planetary body in the solar system. However, being farther from the Sun, Saturn’s chemistry is not going to be quite as dramatic as closer-in Jupiter, and thus Saturn’s atmospheric ‘surface’ is a lot blander appearing.

Saturn: Energy – As is the case for Jupiter, and for much the same reason, solar energy (photosynthesis) is out on Saturn; chemical energy and infrared radiation (heat energy) will be the way to go. Saturn also radiates more heat that it receives from the Sun – two and a half times more in fact; Saturn is also a fantastic place to visit if you’re fond of thunderstorms. Lightning also lights up the skies of Saturn.

To be continued...

Jovian Life: The Moons Versus the Planets: Part One

In our solar system, the planets are divided between the inner terrestrial planets (Mercury, Venus, Mars and of course the Earth) and the outer gas giants, collectively called the Jovian planets (after Jupiter, but including Saturn, Uranus and Neptune), which along with their many moons form the Jovian system. Since it’s easier to look in our own planetary backyard neighbourhood first for alien life, there’s been much speculation about what pieces of solar system real estate, if any, might be suitable abodes for extraterrestrial life. While Mars has always been top-of-the-pops, a once heavily favoured Venus fell by the wayside a while back, only to be replaced with a few bits of real estate somewhat further out. It’s those “somewhat further out” bits of real estate that are now under-the-gun. While most speculation is on selected Jovian satellites, I put the accent on the parent bodies.

If you are a professional scientist interested in astrobiology (exobiology), searching for life in the Universe, your mantra is “follow the water”. If you want to find life, find liquid water first. But liquid water isn’t the total be-all-and-end-all when it comes to finding LGM – Little Green Microbes. Water, based on Planet Earth’s own terrestrial life as the only statistical sample we have, is certainly critical, but so to are lots of other things as we shall soon see.

Astronomy textbooks written until around or about the 1970’s gave little shrift to the Jovian system as an interesting place to look for extraterrestrial life. The Jovian planets and moons were obviously outside the solar system’s habitable or Goldilocks zone, of which Planet Earth was square in the middle of. My how times change, because, following our robotic exploration of the outer solar system, that point of view has had to partly fly out the window, at least with respect to three pieces of Jovian real estate – the moons Europa, plus Titan and Enceladus (orbiting Jupiter and Saturn respectively). Actually Titan is only really interesting from a pre-biotic perspective. While rich in organic molecules/compounds, it’s considered way too cold for really active chemistry and biochemistry to take place. Titan froze before life could actually grab hold. It lacks a viable energy supply, one of the key items required for life-as-we-know it.  

Alas, the parent bodies, including those gas giants further out (Uranus and Neptune) continue to be overlooked as habitable abodes for ET. The logic of this escapes me as we shall soon see, for the idea that the Jovian planets could in theory harbour life forms as complex as jellyfish or other quasi-aquatic life forms even up to and including the equivalents of Jovian dolphins and whales can’t be ruled out. While Jovian extraterrestrial intelligence (ETI) might be possible, Jovian ETI with technology can pretty much be ruled out, and for much the same reason as to why dolphins and whales here on Earth aren’t a technological species - they can’t build things in the environment to which they have adapted to.

So what’s needed to build us an ET? Well, minimum requirements are 1) appropriate life-as-we-know-it chemicals (CHON – Carbon, Hydrogen, Oxygen and Nitrogen – and of course water or water vapour); 2) a proper comfortable environment for life-as-we-know-it (an appropriate temperature range for liquid water or water vapour); 3) mixing that brings the various inorganic and organic chemicals required into proximity; and 4) an energy source(s) to drive things along, like solar energy does for many terrestrial organisms on Earth.

Mars, though not part of the Jovian system, has been associated with extraterrestrial life for over the past century and then some. That association remains to this very day. Mars is still the poster-boy and remains the prime target in the hunt for ET – even though that association has suffered a downgrade from Martians with ray-guns (as in “The War of the Worlds”) to Martians as microbes – though a microbial ET is just as significant a discovery as a Martian pointing a ray-gun at you. The principle is the same; otherwise it’s just a matter of relative biological complexity. 

Europa (Moon of Jupiter): Science fiction writers can sometimes really hit the proverbial nail on the proverbial head. Take Arthur C. Clarke’s “2010: Odyssey Two” (1982) and “2061: Odyssey Three (1988). Clarke had aliens taking an interest in the primitive life forms under Europa's ice. They transform Jupiter into a star to kick-start their evolution. Fifty years later, Europa has become a tropical ocean world from which humans are banned. Well, the aliens, transforming Jupiter and the tropical ocean are flights of fancy, but the primitive life under the ice of Europa might be something else yet again.

Actually Clarke was tipped off by the two Voyager space probe flybys in 1979. The data and images that were captured strongly suggested to scientists that Europa had to have a salty ocean, perhaps a hundred kilometers deep, but an ocean underneath a vast ice sheet, perhaps up to ten kilometers thick. The energy source was tidal friction, the endless to-and-fro tugging via gravity on the moon by Jupiter and Europa’s companion sister moons. The flexing heated up Europa’s interior, and as heat escaped upwards, melted the covering of ice. The freezing temperature of outer space (Europa has no atmosphere to speak of) freezes the surface which then insulates the heated ocean below from further freezing.

So, you have water, an energy source, mixing, and given the water is in a liquid form, you apparently have a suitable habitat for life-as-we-know-it, well sort of. There’s not going to be any photosynthesis, not that far out and sunlight is not going to be very effective in any event after penetrating kilometers of ice. Translated, the oceans of Europa are going to be pitch-black. The analogy with terrestrial biology is life in our marine hydrothermal vent communities – life driven by Earth’s interior heat and the venting of various chemicals from beneath the ocean floor, and chemosynthesis instead of photosynthesis. Europa’s interior composition mirrors the terrestrial rocky planets – iron and silicates and stuff like that. What is less certain is whether there are abundant sources of carbon and nitrogen.

The one really interesting feature we can see on Europa’s surface is numerous streaks of pinkish-red lines and markings. The source is probably upwelling of the waters below as the surface ice rotates and cracks, sort of like ice floes in our polar oceans. There are lots and lots of organics with pinkish-red colors, though organic chemistry doesn’t of necessity mean biochemistry. Still, perhaps examples of Europa’s life (probably microbial) lie as frozen fossils on the surface. That pinkish-red stuff would be prime material for sampling when and if a probe lands on Europa. In conclusion however, the C and the N in the CHON is the big question mark IMHO.

Enceladus (Moon of Saturn): Europa has competition in our local solar system’s ‘where are the aliens?’ extraterrestrial life debate. We move now from the fifth to the sixth ‘rock’ from the Sun. In 2005 the Cassini spacecraft performed several close flybys of the moon of Saturn, Enceladus, revealing a water-rich plume venting from the moon's South Polar Region. This discovery, along with the presence of escaping internal heat and very few (if any) impact craters in the South Polar Region, suggests that Enceladus is geologically active today. The water vapor spewing from Enceladus's surface would indicate the presence of liquid water immediately under the surface of the moon, which, using NASA’s mantra of “follow the water” might make it possible for Enceladus to support life. The presence of liquid water under the crust means there has to be an internal heat source. That heat source is actually sources, a combination of radioactive decay and tidal heating as tidal heating alone is not enough to explain the amount of heat required.

So the data from instruments on the Cassini spacecraft produced evidence of what’s now termed cryovolcanism - cold volcanism - where water and other volatiles comprise the ‘molten’ stuff that gets erupted from these cold ‘volcanoes’ instead of molten iron and silicate rock – like terrestrial lava that is erupted from our own hot volcanoes.

These cold volcanic eruptions – basically ejections of vapor clouds into space - have been, as noted above, discovered on Enceladus. The detailed composition of these gas clouds are in the main mostly water vapor, plus some other minor volatile components like molecular nitrogen, ammonia, methane, and carbon dioxide. Additional observations have revealed further chemicals in the plume, including both simple and complex hydrocarbons such as propane, ethane, and acetylene. These chemicals and their relative abundances are similar to those seen in many comets. Perhaps Enceladus was once a super-giant comet that got captured by Saturn’s gravity!

All up, these findings raise the possibility for the existence of potential life forms existing beneath the surface of Enceladus. The composition of the gas cloud plume strongly suggests that its source is a subsurface salty ocean or subsurface caverns filled with salty water. Enceladus is therefore a prime candidate for those wishing to investigate non-terrestrial sites harboring potential extraterrestrial life. We have CHON, energy sources, an appropriate temperature regime underneath the surface, and probable mixing, since liquid water facilitates mixing.

Titan (Moon of Saturn): I’ve already noted that while Titan is fascinating from an astrobiology point of view, that point of view is from those interested in pre-biotic organic chemistry that leads to biochemistry, not those hopeful of actually seeing things wiggle. Translated, while it has the CHON, and probably mixing, that’s just about it. The environment is way too cold which suggests that energy available to drive biology is in pretty short supply.

To be continued...

Exobiology: Life in the Solar System: Summary & Conclusions

Exobiology was the original term given to the sciences central to the question of life-in-the-Universe. It’s now been largely replaced by Astrobiology, but I’ll stick with the original. To investigate life-in-the-Universe perhaps we should start a bit closer to home and look to our own solar system. Apart from Planet Earth, we have no absolute proof positive to date that any other life, albeit relatively simple forms compared to terrestrial life forms such as ourselves and associated companion animals and plants, exists within the confines of our solar system. However, I conclude in this overall summary the odds are fairly high, almost certain in fact; those other, albeit relatively simple extraterrestrial life forms do exist in our immediate cosmic neighbourhood. 

Life is ultimately nothing more than an ongoing series of complex biochemical reactions. These sort of reactions tend to be optimal at warmer (quasi Earth-like) temperatures. Too cold and the necessary chemical reactions are too sluggish, if they proceed at all. Too hot, complex organic molecules rapidly break down. So, Titan (moon of Saturn) is probably way too chilly even though it has a thick atmosphere and lots of organic molecules on the surface, even organic liquids forming large lakes if not exactly oceans. The surface of Venus in contrast is way too hot, but it has a thick atmosphere that’s a lot more temperate at higher altitudes. Some real estate is both too hot and too cold at the same time – Mercury and Luna (our Moon) for example and lacking any real atmosphere and liquid water aren’t top of the pops for finding life, however simple.

Mars, long associated with intelligent extraterrestrial life, is still a near certainty for much housing far simpler extraterrestrial life forms, like microbes. There are many independent chains of observational evidence that support that conclusion. Proof positive however, still waits.

Europa (moon of Jupiter) has in all probability a liquid water ocean beneath a global ice cap. Water plus a geothermal/tidal energy heat source opens up a good plausibility for going ice fishing to our descendents several generations down the track. There are several other moons with ice cap surfaces covering possible liquid oceans that might rival Europa as an eventual fishing destination.

My favourite solar system locations for (probably) tough-as-nails microbial life, Mars apart, are the upper atmospheres of the Jovian (gas giant) planets (Jupiter and Saturn; maybe Uranus and Neptune). Their atmospheres are rich in organics and no doubt water vapour.  The gas giants, Uranus excepted, radiate more heat energy than they receive from the Sun. There will be regions in their upper atmospheres that have Earth-like temperatures; there will be a lot of atmospheric mixing (useful for bringing different chemicals together); and of course these planets will also have been seeded with organics and water from space via comets, meteors, cosmic dust, etc., if not in fact seeded directly with microbial life forms via the Panspermia hypothesis.

The problem in finding out for sure is going to revolve around sending appropriate instrumentation into those planetary atmospheres that will be able to detect actual life forms, as opposed to just measuring just purely physical parameters and chemical constituents. So, don’t expect definite answers anytime soon.  

Lastly, we can’t rule out comets and meteors from housing dormant extraterrestrial microbial life forms.

Exobiology: Life in the Outer Solar System: The Smaller Bodies

Exobiology was the original term given to the sciences central to the question of life-in-the-Universe. It’s now been largely replaced by Astrobiology, but I’ll stick with the original. To investigate life-in-the-Universe perhaps we should start a bit closer to home and look to our own outer solar system and some of the smaller abodes. Apart from Planet Earth, we have no absolute proof positive to date that any other life, albeit relatively simple forms compared to terrestrial life forms such as ourselves and associated companion animals and plants, exists within the confines of our solar system. However, the odds are fairly high, almost certain in fact; those other, extraterrestrial life forms do exist in our immediate cosmic neighbourhood. 

Europa (A Satellite of Jupiter): Europa is, apart from Mars, the current darling of the exobiology (astrobiology) set. There is evidence that Europa has a liquid water ocean underneath a thick ice cap that is kept from freezing solid by the flexing action imposed on the moon by its parent planet, Jupiter. If you have liquid water, an energy source, you therefore have possible life, or so goes the thinking.  I’m not quite as optimistic. The ice cap is thick enough so that any energy source available for life won’t be solar. The ocean will be in eternal darkness. That is however not a death blow as not all critters on Earth rely on solar energy. There could be hydrothermal vents, with associated living communities on Europa as there is on Earth. But, with the ice cap, there would be little in the way of resources added to the ocean from outside; that’s not the case on Earth. All chemicals that would sustain such life would have to be efficiently recycled. Life on Europa – possible, but it’s going to prove to be very difficult to explore that ocean, so I’m not expecting a definitive answer any time real soon.

However, there remains the possibility that materials contained within that hypothetical ocean may, due to tidal stresses, may be squeezed through cracks in the ice and find their way to rest on the surface. It’s therefore possible that a robotic craft that lands on the icy surface might detect organics and/or fossil or frozen solid microbes or even dead multicellular life forms resting on the surface.

[Note: To avoid unnecessary repeats, as a general rule of thumb, any satellite around Jupiter, Saturn, Uranus or Neptune that has a substantial part of it’s crust made up of ice, and is subject to extreme tidal heating by it’s parent planetary body (i.e. – you get a liquid ocean underneath a thin covering of ice), you have the potential for, as in the case of Europa, a habitable water-rich environment.]

Titan (A Satellite of Saturn): The satellite of Saturn, Titan, is one of the largest moons in the solar system, and in fact, if it existed all by its lonesome, could be considered a planet in its own right. Titan has, fairly unique among satellites, a dense atmosphere. It’s denser in fact than our own atmosphere. It also has the right sorts of chemicals that we identify as having a strong connection with organic and biochemistry. Were Titan the same distance from the Sun that Earth is, well, you could have a real twin of Earth, unlike our false twin, Venus.

Unfortunately, Titan is way, way, way – far away – from the solar energy source that makes Earth such a relative paradise. Thus, Titan is Earth, but an Earth in slow motion because Titan is so cold compared to Earth. If you think of Earth as liquid water at the equator, Titan is molasses at the poles!

Comets, Asteroids/Planetoids, Meteors: These relative tiny bodies can’t really qualify as habitable abodes to life, except, there’s evidence that not only can some of the above be rich in the sorts of chemicals associated with life (water, carbon compounds and organic chemistry), they could indeed be environments that could house dormant life forms or fossil life forms of a unicellular kind. Meteorites which have been gathered up and analysed on Earth (like ALH 84001) have yielded if not fossilised bacteria, then at least enough chemical evidence to suggest that they could have had a close connection with contributions towards an origin of life event.

Exobiology: Life in the Outer Solar System: The Gas Giants and Pluto

Exobiology was the original term given to the sciences central to the question of life-in-the-Universe. It’s now been largely replaced by Astrobiology, but I’ll stick with the original. To investigate life-in-the-Universe perhaps we should start a bit closer to home and look to our own outer solar system, starting with the gas giants (Jupiter, Saturn, Uranus and Neptune) and Pluto. Apart from Planet Earth, we have no absolute proof positive to date that any other life, albeit relatively simple forms compared to terrestrial life forms such as ourselves and associated companion animals and plants, exists within the confines of our solar system. However, the odds are fairly high, almost certain in fact; those other, extraterrestrial life forms do exist in our immediate cosmic neighbourhood. 

Taking each of the four gas giant abodes (the Jovian planets) in the outer solar system followed by Pluto in turn…

Jupiter (The Giant Planet): Jupiter is the largest planet in our solar system, but composed mainly of gas. In fact, Jupiter has been insulted by being compared to our Sun, but a failed Sun. If Jupiter had been a fair few masses larger, it would have ignited in a ball of thermonuclear fusion and become a second stellar object in our solar system, turning it into a binary star system. Jupiter however is still solar enough such that it emits more energy than it receives from the Sun. Jupiter, because of the intense gravity, compresses its own stuff, and compression produces heat. Important point number one: Jupiter has its own internal energy source.

Important points two, three and four: Secondly, Jupiter’s atmosphere is composed of the right sorts of chemicals that one identifies with origin of life events – hydrogen, methane, ammonia, water vapour, etc. Thirdly, Jupiter’s atmosphere is turbulent such that there is a lot of mixing of those elements and compounds. Fourthly, the atmospheric bands of Jupiter are highly coloured, an indication that there’s lots of complex chemistry including organic chemistry going on within.   

The upshot of all of this is that it is not implausible that within the upper reaches of Jupiter’s atmosphere, as per the case of Venus, simple life forms couldn’t exist, survive and thrive. You have the chemistry – you have the energy. And maybe Carl Sagan was right and that something more complex than just a unicellular ecosystem could exist in Jupiter’s atmosphere. But it would have to be an atmospheric ecology.

Saturn (The Ringed Planet): Saturn is a quasi twin of Jupiter. Although slightly smaller and farther away from the Sun than Jupiter, the same general arguments that apply to Jupiter apply to Saturn. That is to say, Saturn has the right sorts of chemistry – and an internal energy supply. It’s however slightly less dense than the other gas giants, such that if you could find an ocean big enough, Saturn would float! That however has no bearing on the issue of finding an atmosphere-based ecosystem there.

Uranus: Uranus is a poor cousin compared to the likes of Jupiter and Saturn. It’s mainly a gas planet, albeit way smaller, but so far out from where it’s all happening that it isn’t too likely that even simple life could flourish in the atmospheric depths, although the chemistry isn’t dissimilar to that of the closer-in Jovian planets of Jupiter and Saturn.

Neptune: The same sorts of arguments apply in general to Neptune as to Uranus, with one slight exception. Although farther out, Neptune, like Jupiter and Saturn, radiates out excess energy. It’s solar independent, at least as far as any life forms might describe their environment and energy supply.

Pluto: The planetoid Pluto was recently officially demoted from strict planetary status, and is no longer acceptable to refer to it as the ninth planet. However, when I was growing up, it was the ninth planet, and so I say buggers to astronomical officialdom. That rant aside, Pluto is hardly top rock for vacation seekers. It’s cold. I mean it’s really cold. It makes Antarctica seem absolutely tropical in comparison. I mean polar bears would freeze to death on Pluto, not that there’s anything reasonably resembling an atmosphere as we know it for them to breathe. Again, Pluto is too cold to allow for the high temperature chemistry we associate with life-as-we-know-it. If you’re looking for life in our solar system, Pluto wouldn’t be your first port of call.