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Hi everyone! Sorry that the posts were thin on the ground last week. The head druid told me that I needed to honor the solstice by taking some time to reflect on the meaning of things [citation needed]. Anyway…since I didn’t blog last week, I failed to post these astonishing pictures of Jupiter’s giant moon Ganymede, which were photographed by NASA’s Juno spacecraft as it slaloms though the Jovian system.
Although its lack of atmosphere and pockmarked plains of dust make it superficially resemble Earth’s moon, Gannymede is a very strange and unique heavenly object Of the 200 known moons in the solar system, it is the largest. Indeed it is 26% larger than the planet Mercury by volume (although it is only 45% as massive as the metalliferous first planet). Ganymede has a diameter of 5,268 km (3,273 mi), so each pixel in the full size image of the Jovian moon is equal to a kilometer (although you may want to check out the NASA image to really savor that scale–since WordPress has a noteworthy penchant for scrunching up my images in incomprehensible ways).
Alone among moons in the solar system, Ganymede has a magnetic field, albeit a rather meager one compared to Earth or Jupiter. Scientists surmise that the magnetic field is created by convection within the liquid iron core of the moon–although answers are not forthcoming as to why it has a liquid iron core to begin with (these planetary cores seem to be the real determinant of what planets are like, but I feel like we know precious little about them). Thanks to its size (and maybe thanks also to its magnetosphere), Ganymede has a very thin oxygen atmosphere…but that just creates more question, since elemental Oxygen has a tendency to instantly bond to all sorts of other elements. The 20 percent or so of oxygen in Earth’s atmosphere did not become a mainstay until about 1.5 billion years ago when photosynthesizing bacteria finally became so prevalent that they overcame the constant loss of atmospheric oxygen thanks to oxidation. Hopefully Juno’s survey will help us solve atmospheric mysteries on Ganymede. Ganymede is also believed to have a vast subsurface ocean of icy water tucked away somewehere beneath its surface. Astronomers have reasonably speculated that this Ganymede underworld ocean may contain more water than all of Earth’s oceans combined!
Ganymede is a Galilean moon–which means it was discovered by the great scientist, and is one of the first objects ever discovered to orbiting another planet (I still sometimes imagine the thrill Galileo must have felt when he realized what he was seeing). I wonder what surprises Juno will send back for us!
Meanwhile…three quarters of a billion kilometers away, the Juno space probe continues its exploration of the gas giant Jupiter. The probes orbit brings it to within 4,200 kilometers (2500 miles) of the cloudtops once every 53 days. So far, Juno has made 10 such passes (out of a planned 12 before the mission’s end in July). As the astrophysicists and planetary scientists work to make sense of mission data, NASA has made the raw image data available to the world. Private citizens have used it to create these stunning images of the largest world in the Solar System. Since I can’t even begin to explain the vast atmospheric complexities behind these swirling psychedelic wonders, I will leave them here without comment. Marvel at our huge planetary neighbor with its marbelized super storms and spare a moment to thank Gerald Eichstädt & Seán Doran for putting these amazing pictures together.
There are more pictures coming in from NASA’s Juno mission to Jupiter and they are amazing. The plucky space probe has entered an orbital pattern which causes it to swoop from one pole of the gas giant to the other in 2 short hours (that may not sound like a short period…but Jupiter is enormous). As it passes close to the gas giant, Juno has been able to photograph and record hitherto unknown features of the fifth planet from the sun—such as a magnetic field twice as powerful as predicted and intricate and heterogeneous ammonia weather systems.
Perhaps the most stunning aspect of this new trove of data comes from Jupiter’s previously unexplored poles which are filled with intricate webs of cyclones—each up to 1400 kilometers in diameter. You can see them here on astonishing photos. Scientists are eager to learn more about the storms—and what lies beneath them. The coming months will feature even more beautiful images from the solar system’s grandest planet—and maybe we will get some answers too concerning what is under the clouds and what powers these colossal storms on our breathtaking neighbor.
Based on what we are learning from the exoplanet surveys of the past decade, our galaxy is the home of an immense number of Jovian-size gas giant planets. There are countless “hot Jupiters”–gas giants located close to their stars which whip around and around their orbits in ridiculously short “years”. There are frigid slow gas giants and super massive ones—practically brown dwarves– which are larger than Jupiter. There is an endless proliferation of Uranus and Neptune type giants. Imagine them all glittering in strange colors with weird shapes. They are cloaked in alien clouds and covered in mysterious storms. Who knows what lies beneath?
All of these billions of giant planets seem pretty hypothetical to me as I sit here at my cramped & cluttered desk on solid little Earth. Yet they exist. They are out there in numbers too vast to comprehend. However, right now, NASA is conducting the most comprehensive exploration yet of the gas giant we can access. Juno’s mission is just getting underway in earnest, and the largest gas giant in our own backyard should reveal lots about all of the billions which are out of reach.
I am sad that I can neither understand nor convey the loftiness of this crazy ongoing mission. It is an astonishing undertaking—but we are so inundated by with murky political battles and vulgar popular drivel, that it is hard to see the utterly astonishing nature of this undertaking.
Maybe I can put it in perspective somewhat. Imagine back to the year 1609 AD when Henry Hudson was first seeing the river which was later named after him. Before him was an exquisite expanse of islands, bays, and sparkling river. The vast waterway flowed down from unknown mountains into a bay surrounded by lovely islands. The whole expanse was filled with flocks of unknown birds and schools of fish. Beyond the thriving marshes, mysterious forests were filled with moving shadows.
Now multiply that a billion times: replace Henry Hudson with a tiny fragile robot and replace the Hudson River with luminous gas oceans large enough to entirely submerge scores of Earths. That is what is happening right now. As you sit reading this on a little glowing screen, we are making fundamental discoveries about a whole planet.
On August 27, 2016, Juno executed the first of 36 orbital flybys over Jupiter. The doughty spacecraft was only 4,200 kilometers (2,500 miles) above Jupiter’s atmosphere. It sent back the first detailed images of the north pole of Jupiter—and it is unlike the rest of the planet.
The North Pole of Jupiter as seen by Juno [NASA]
To quote Scott Bolton, one of the lead scientists of the Juno mission, “[The] first glimpse of Jupiter’s north pole…it looks like nothing we have seen or imagined before….It’s bluer in color up there than other parts of the planet, and there are a lot of storms. There is no sign of the latitudinal bands or zone and belts that we are used to — this image is hardly recognizable as Jupiter. We’re seeing signs that the clouds have shadows, possibly indicating that the clouds are at a higher altitude than other features.”
Jupiter’s clouds contain whole continent-like regions of air which are different than the rest of the planet’s storms and whirls. We don’t yet know why or how, but we are finding out. As we do so, we are peeling back a layer of mystery which surrounds all such worlds.
Solar Radiation Streaming over the North Pole of Jupiter
The other day I rashly promised a post about Juno—or I will call her “Hera” since the Greeks invented her (?) and their name is more euphonic. Immediately though it became obvious that writing about the queen of the gods is not as simple as it seems. Hera plays the villain in many myths—particularly those of Heracles (indeed, her name is his name: Heracles means “Hera’s man”). She is a great and terrible antagonist–even more so than giant sentient animals, or super dragons, or the dark monstrous deities of the underworld. But why is that? How can a regal woman be so much worse than the gods of charnel darkness and stygian torture?
The Goddess Juno in the House of Dreams (Luis Lopez Piquer ca. early nineteenth century, oil on canvas)
Hera is the eldest daughter of Rhea and Cronus. She was devoured by her father at infancy, but escaped (via mustard emetic) and joined her brothers and sisters fighting against the titans for world domination. Once the battle was won, she initially rebuffed the romantic overtures of her youngest and strongest brother, Zeus. The king of the gods then took the form of a bedraggled cuckoo and cunningly played upon her sympathy for small injured creatures in order to win her heart and her hand. After their marriage, however, Hera played the cuckoo in their relationship as Zeus dallied with goddesses, nymphs, and comely mortals of all sorts. Classical mythology is pervaded by a sense that Zeus, king of the gods and lord of creation who fears nothing (except for being replaced by a strong son) is extremely afraid of Hera. She is often portrayed as jealously lashing out at Zeus’ paramours and their offspring…or otherwise punishing those who act against her will or fail to pay her sufficient respect.
Juno Discovering Jupiter with Io (Pieter Lastman, 1618, oil on canvas)
Hera’s animals are the lion, the cow, and the peacock (she put the hundred eyes of her dead servant Argus on the bird’s tail to give it even greater beauty). Her emblems are the throne, the chariot, the scepter, and the crown. She is sometimes portrayed wearing a strange cylindrical crown of archaic pre-Greek shape (which may indicate that she was a goddess of power borrowed from a pre-Greek society).
Hera tends to be portrayed as a rich powerful woman of a higher class who barely deigns to notice her inferiors. She is the goddess of women, marriage, wealth, success, and (above all) power. Her children are Ares, Hephaestus, Eileithyia (the goddess of childbirth), cruel Eris, and beautiful Hebe, the goddess of youth who married Hercules after his apotheosis.
Have you read “The Three Musketeers”? After spending the entire book struggling against the machinations of Cardinal Richelieu, the hero prevails and join forces with…Cardinal Richelieu. Power is like that, and so is Hera. She can’t effectively be fought against. The world is hers. She can only be appeased or beguiled… or served outright.
The way upwards is not through deeds of merit, or valorous acts, or fighting monsters—it is through political wiles, networking, and figuring out how to please extremely rich powerful people who are impossible to please and implacably oppose regarding you as any sort of equal.
Happy (belated) Fourth of July! While everyone was out barbecuing and amusing themselves with colorful novelty explosions, there was big news in space exploration: NASA’s Juno probe, which launched from Earth five years ago, has finally reached the gas giant planet and entered orbit. The robot spacecraft, which is about the size of a basketball court, is now dancing nimbly amongst the system of moons and rings and radiation belts around the giant world.
The probe is a remarkable spacecraft. It traveled 2.7 billion kilometers (1.7 billion miles) to reach the exact orbit which NASA planned for it. The secret behind its astonishing precision (even when traveling at 165,000 mph) is the autonomy of its sophisticated navigational computer. Mission controllers do not have to radio the probe from half-way across the solar system (which would take minutes—or longer. Instead the probe navigates itself. The ship computer is shielded beneath a titanium vault to keep radiation from frying its clever electronic brain.
Oh man!
Among the planets, Jupiter is a sort of greedy eldest child. Scientists who study planetary formation believe that the gas giant formed first of all the planets and it took the lion’s share of available matter left over from the formation of the sun. Jupiter is more than twice as massive as all the other planets in our solar system put together: indeed, it is three hundred and eighteen times more massive than Earth. Yet we know shockingly little about this bruiser. Very basic questions about Jupiter remain unanswered. For example we still do not know whether the planet has a rocky core beneath its vast colorful atmosphere.
As we learn more about exoplanets which orbit other stars, questions about the formation of solar systems have become more numerous. Astronomers have been particularly perplexed by the number of “hot Jupiters,” giant gas planets which are extremely close to their stars. Was Jupiter such a world at some point before moving to its current location, or is it a huge freak? We simply do not know. Scientists would also like to know more about the unimaginably vast cloudscapes of Jupiter. What dynamics move these huge bands of pressurized gas?
As Jupiter formed, it was bombarded by strange radiation. The depths of Jupiter’s storms must still feature giant lightning strikes. This sort of treatment can cause hydrocarbons and ammonia to form amino acids. Maybe life has a Jovian origin. Maybe Jupiter still has life floating around like aerial zooplankton. Again, we just don’t know much about the giant world…
Did anybody see that amazing episode of “Cosmos”?
However, now that Juno has arrived we can start to answer some of these questions. The probe will go through various start-up and test sequences until Oct. 19 when it moves to a 14-day orbit of the planet and really starts scrutinizing our giant neighbor.
Oh, one more thing—NASA has been getting better at PR to make space more accessible and “fun” for us laypeople following at home (as witnessed by the July 4th arrival). Juno also has a crew of three Lego astronauts: Galileo, Jupiter, and Juno herself. This leads me to write about Juno herself, for she is a terrifying figure among the gods. More about her tomorrow!
A Close-up photo of a Foxglove from "Ledge and Gardens"
The garden at my new residence contains a variety of beautiful old trees (like the cherry tree which I wrote about this spring). While the trees are delightful and are clearly the best features of the garden, they do make flower gardening a challenge. Fortunately there is a very beautiful plant that thrives in the dappled shade—the foxglove. I just planted two mature specimens which I obtained from the nursery and I am delighted with them! I thought I should feature a picture of them here before their flower spikes get broken.
Foxgloves in my Brooklyn Garden
Because they are so tall and elegant, foxgloves have been a garden mainstay for an extremely long time. About twenty species of wild foxgloves (the genus in named “digitalis”) are indigenous to Europe, North Africa, and Western Asia. The plants are biennials and they produce foliage in a low basal clump. During the plant’s second year, a tall rosette rises from the leaves and produces a series of purple, white, or pink tube-shaped flowers. The throats of these flowers are mottled with lovely speckles.
A Second Photo from the Garden
Foxgloves have long been associated with magic and myth. In Roman mythology, the goddess Juno was angered that Jupiter had given birth to Minerva without a mother. Juno aired this grievance to Flora, the goddess of flowers, who then lightly touched the queen of gods on her breasts and belly with a foxglove. Juno was impregnated and gave birth to the war god Mars, who, in the Roman canon has no father (like certain turkeys!). The Scandinavians call the plant “fox bells” a name which references an ancient fairy tale about how foxes magically ring the flowers when hunters are coming (so as to warn their kind of peril). On her botanical folklore website, Allison Cox wrote “In Wales, foxglove was called Goblin’s Gloves and was said to attract the hobgoblins who wore the long bells on their fingers as gloves that imparted magical properties.”
A Patch of Foxgloves
Unfortunately, the plant has a very real dark side. All parts of the foxglove are toxic. Mammals that have ingested digitalis suffer tremors and nerve disorders (particularly xanthopsia, a visual impairment in which the world becomes suffused with yellow and haloes appear around lights). Even a small amount of the poison is enough to cause deadly disturbances of the heart.
Because of its ability to affect the heart, digitalis was one of the very first cardiac medicines. The biochemistry website “Molecule of the Month” relates that, “Digitalis is an example of a cardio-active or cardiotonic drug, in other words a steroid which has the ability to exert a specific and powerful action on the cardiac muscle in animals, and has been used in the treatment of heart conditions ever since its discovery in 1775.” The site has a very entertaining anecdote about how William Withering, the proper English doctor who made this discovery was forced to prowl the forgotten byways of Shropshire and bargain with a gypsy sorceress to find out which compound had healed a patient with a fatal heart problem.
Because foxglove was actually useful for certain heart problems, it was also prescribed (or self-administered) to people suffering from palsies and nervous disorders. There were very few effective neurological drugs available at the time and it was believed that digitalis might somehow help (an unfortunate fallacy). Legend relates that Van Gogh used foxglove to treat his epilepsy. If true it might explain the yellow hue of his late paintings. Digitalis poisoning is known to cause xanthopsia, but whether Van Gogh was truly inspired by the poison flower or just loved yellow will probably forever remain unknown.
Le Café de Nuit (Vincent van Gogh, 1888, oil on canvas)
ferrebeekeeper 