Ceres: A World of Winter in Spring

[Music] her heart and features are transformed that face which even dece must have found unhappy beams with joy as when the sun long lost and hidden in the clouds and rain rides forth in triumph from the clouds again so series had regained her subpoena of it the romans were not a mystically minded people like every culture that has ever existed they believed in gods however they tended to see religion in a similar vein to town planning or the construction of aqueducts if the rules were followed the texts adhered to the proper motions and speeches performed then the metaphysical needs of the roman people were met there was as little need to garnish the job with flights of fancy as there was to carve angels into a kitchen table the earliest recorded latin religious texts the books of the college of pontiffs speak not of wild magic or seething monsters slain by flowing haired heroes atop hybrid beasts but of commentaries and concordances on proper prayers and rituals and their connection to the finer points of roman law to anyone familiar with the code of justinian this will seem archetypically roman the few mythological tales they did celebrate largely involve people not gods such as the famous founding myth of the babies romulus and remus suckled in the wild by a she-wolf whenever they required a theistic fable to color their pantheon they simply stole it from the greeks whose gods thanks to a common indo-european origin mostly overlapped with their own roman writers were acutely aware of this disparity the greeks shaped bronze statues so real they seem to breathe said virgil in the aeneid and carve cold marble until it almost comes to life the greeks compose great orations and measure the heavens so well they can predict the rising of the stars but you romans remember your great arts to govern the peoples of authority to establish peace under rule of law to conquer the mighty and show them mercy once they are conquered many of rome's conquests would arguably dispute that last line but it's fair to say rome took most of that remembrance to its grave this disparity is ably demonstrated by one of rome's most celebrated goddesses ceres mother of the harvest for whom no native roman tales survive at all and whose identity from the earliest times of the republic was tied to her greek equivalent demeter the earth mother while ceres's name survives today in the word serial it's fair to say that if we moderns know her at all it is as an avatar of demeter it's not like the romans ignored ceres as patron of the harvest she was also the patron of farmers and by extension the plebs the lower rank of rome citizens her seven day spring festival serialia included chariot races in her honor at the circus maximus they just left it to the greeks to give her a personality but the plebs alone could not keep rome fed by the time of the republic most of rome's grain was imported and of that the majority was taken from what the romans called magna gracia or greater greece the fertile southern coast of italy in sicily a wellspring of greek culture and home to one greek colonies like syracuse with most of rome's grain coming from greek speaking lands it's not surprising that her goddess of the grain became greek ceres's oldest sanctuary lay in the sicilian town of anna and later roman theologians would refer to sicily as ceres's earthly home and it would be in sicily 13 centuries after the sack of rome that one pious man would grant ceres a place in the heavens once again on the first of january 1801 the first day of the 19th century giuseppe piazzi an astronomer and catholic priest observed something that until then no human being had ever seen giacino giuseppe maria elvaldo nicolo piazzi better known as giuseppe piazzi was not a native of syriza's homeland in fact he was born in 1746 in lombardy at the opposite end of italy it would be fair to say he did not have the best start in life the ninth of ten children most of whom died in infancy he was granted a home baptism according to his certificate because quote of impending danger of death regardless he survived and in keeping with the tradition of younger sons of noble families entering the clergy entered the theateen order at 19 and after a teaching career that sent him careening across the mediterranean entered what would in due course become the university of palermo where in 1787 despite having little astronomical experience he was made chair of astronomy he proved to be the right man for the job erecting a new observatory in near months and taking time off to travel to paris and london to get some actual astronomy under his belt and learn from masters of the time including jerome lelong neville masculine dominique cassini and most significantly giving piazzi's future achievements william herschel one odd trait of humanity is our ability to normalize even the most world-shattering discoveries in 1781 william herschel while scanning the sky for binary stars became the first human being in recorded history to discover a planet but by the time he met with piazzi astronomy had moved on and already began searching for another planet the idea that the solar system may be incomplete can be traced back to johannes kepler who in keeping with his numerological and astrological obsessions became convinced there was a gap between the orbits of mars and jupiter this appeared validated in 1766 when johann daniel tisius formulated an equation that appeared to accurately predict the orbital positions of the solar planets if one started at zero then added three then doubled it then doubled it again and so on and then added 4 to each number and divided by 10 it produced a remarkably close approximation to the orbital distances of the planets in astronomical units but only if one allowed for a gap between the orbits of mars and jupiter where the law predicted a planet should lie at 2.8 au because this equation was popularized by the better known astronomer johann ellert boda initially without crediting tishius it became known as boda's law and today is usually called leticious boda law until 1781 astronomers had mostly considered the tishious boda law a curiosity then the discovery of uranus shot it into the glaring light of science uranus's orbit fit the law almost perfectly the tiscious body law it seemed was real which meant there had to be a planet between mars and jupiter by 1800 this cosmic inconsistency motivated baron franz sauer von zakh astronomer of the duke of gotha and director of the seaburg observatory in switzerland to gather together a team of the best sky watchers of his time to track down that elusive object this team of elite star crunchers which von sak would nickname the himals pelitzei or heaven's police custodians of the proper cosmic order would ideally comprise 24 members each of whom would be given half a zodiacal constellation to search candidates included charles messier william herschel pierre michonne jerome lelong and naturally giuseppe piazzi except lelon declined to participate due to other commitments and it seemed herschel was never ultimately invited neither it seems was piazzi though his friend barnaba oriani was in fact piazzi was completely unaware of the himmle's bulitzai or of its intentions his goal which he had pursued ever since installing a highly capable astronomical circle at the palermo observatory was to accurately catalog the positions of stars a task he completed in 1803 but as herschel had proved before him and clyde tombaugh and mike brown would prove after him the best way to succeed at astronomy is to just keep staring until you see something and on the 1st of january 1801 piazzi saw something it was a flicker barely brighter than a star and showed no disc but it was moving gyatso must have had some inkling of what he had found because his immediate reaction was to send out two letters the first was to his friend oriani the second was to johan ellert boda to orianni he said quote i have announced this star as a comet but since it shows no nebulosity and moreover since it has a slow and rather uniform motion i surmise that it could be something better than a comet however i would not by any means advance publicly this conjecture as soon as i shall have a larger number of observations i will try to compute its elements to beta he said on january 1st i discovered a comet in taurus it is very tiny and reaches at most a star of the eighth magnitude without appreciable nebulosity please let me know if it has already been observed by other astronomers for in that case i will not bother with the calculation of its orbit why piazzi deemed to relay his suspicions to orianni and not to boda has never been understood boda certainly didn't understand it writing in 1802 that quote it is absolutely incomprehensible to me why mr piazzi in his letter of the same date to me calls his discovered moving star a comet and even in some of the following letters insists on this opinion disregarding my objections and nevertheless in his first letter to mr oriani favors its planetary nature within two months of receiving piazzi's letter boda had calculated an ephemeris for this new object realized that it complied with the law almost supernaturally and immediately alerted von zakh who began feverishly scouting piazzi's cited positions but piazzi's planet was proving difficult to catch as months drew on without the confirmation astronomers distracted themselves with a more esoteric question what to call the bloody thing for piazzi there was only one name for his planet series ferdinandia both after the goddess and patron of sicily and after the kingdom of sicily's then current ruler ferdinand the first much like herschel with his georgian sidus or galileo with his medekia sidera piazzi knew what side his bread was buttered on but it seemed other astronomers had their own ideas border was already calling it juno after the wife of jupiter while van zak was already calling it hera which is just the greek name for juno these names had spread across germany before piazzi had even gotten a word in writing to oriani in 1801 he said quote if the germans think they have the right to name somebody else's discoveries they can call my new star any way they like as for me i will always keep it the name of series and i'll be very obliged if you and your colleagues would do the same which is fair enough but this debate would be for naught if piazzi's planet could not be found by december 1801 fonsach was getting testy quote what is going on with the series ferdinandia nothing has been found as yet either in france or in germany peoples are starting to doubt already skeptics are making jokes about it what is devil piazzi doing laland wrote me that he piazzi has changed again his observations and he has made a new edition of them what does that mean lalon in his letter adds this is why i do not believe in the planet thankfully on december 31st 1801 fonsac finally caught what he called this coquette series and piazzi's honor momentarily in question was restored ceres was found to lie at 2.77 au from the sun almost exactly as predicted by the tisch's bowed law science had won again or not the discovery of neptune in 1841 threw a wrench into the whole idea of boda's law as neptune was over 8 a.u closer to the sun than the law predicted today the overwhelming consensus about the tisch's boat law is that it is a coincidence neither for the first nor the last time belief in mathematical ghosts was trumped by tireless assiduous hard graft and then on the 28th of march 1802 the bomb dropped heinrich obers badge carrying member of von zak's patrol observed a second object with a nearly identical orbital period to ceres which he named palace after an epithet for the goddess athena ironically palace was tilted to the ecliptic by 34 degrees which meant that it was pure luck that it happened to be near ceres at the time had it been anywhere else the himmel's politzi which had confined its search to the zodiac would never have found it william herschel after observing both objects argued that as they were clearly neither planets nor comets they required a separate designation and suggested asteroids meaning star-like as they resolved no disk even at the highest magnification and thus resembled stars it would be decades and the discovery of a hundred more asteroids before the name was taken up the himalayas pulitzai did eventually get their name when the asteroid juno was discovered in 1804 and with the discovery of vesta in 1807 they declared their mission over by the time the next asteroid astraya was found in 1845 only one member of the group the mathematician johan gauss remained alive if there is one story that everyone knows about the goddess series slash demeter it is that of the abduction of her daughter persephone or proserpina to the romans by hades or dies this story is often read as a straight-up rape though most classical sources depict it as an arranged marriage zeus hades's brother and persephone's father agreed that his daughter should marry hades but also knew that demeter would never accept it so he sanctioned that haiti should abduct the unsuspecting persephone before her mother could interfere i leave it to you to decide if that take is better or worse demeter's sadness at losing persephone turned the land barren and the people began to starve eventually a compromise was reached whereby persephone could spend half the year with her mother and half the year with her edge lord husband when her daughter is with her demeter's joy spills out over the world and the harvest is bountiful but when her daughter returns to the underworld she descends into depression and the land dies hence creating the seasonal cycle like the earth mother for whom she is named ceres the peculiar worldling amid the swarms of the asteroid belt is tied to seasons both mundane and cosmic as the number of known asteroids within its belt climbed astronomers began to realize that they fell into various groups the most obvious were the kirkwood gaps regions of the belt in precise resonance with the orbit of jupiter which over time allow the giant planet's gravity to clear them of debris but alongside this astronomers began to notice certain variations in the matter of which they were composed the innermost region of the asteroid belt comprises what astronomers call s-type asteroids dominated by iron and rock and almost devoid of water vesta is among these and in fact is a parent of its own family of s-type-like asteroids called the v-type asteroids mid region of the belt is dominated by c-type asteroids the commonest type of asteroid c types are dominated by carbon and other elements common to the sun and gas giants they average about 10 percent water by mass and are believed to be largely unaltered primordial relics from the solar system's formation this region is also home to the rare g-type asteroids which include ceres these asteroids have a higher level of carbon and signs of water evaporation on their surfaces as well as hydrated mineral forms such as clays the outermost region of the belt is dominated by d-type asteroids dark carbonaceous objects that resemble comets or kuiper belt objects there seem to be an obvious reason for this the farther an object is from the sun the less sunlight it receives and thus the more likely it is to preserve volatile substances like water the solar system possesses a region called the frost line or snow line which is the distance from the sun at which water can remain frozen except that distance which is the point at which comet's tails form is about 5 a.u far beyond the asteroid belt and almost the distance to jupiter astronomers now believe that the asteroid belt is a fossil of an ancient time in our solar system's history when the planets were still forming and the sun was dim and cold at the time of the asteroid's formation the sun was just seventy percent its current brightness and its snow line lay right at the boundary between the inner and mid-level belts beyond this point water and other volatiles froze to their surfaces over eons as the sun's light grew stronger the primal winter gave way to our current age the water on their surfaces evaporated leaving only that trapped within the minerals or safely buried under regolith ceres and the asteroids like it are relics of an ancient winter preserved into cosmic spring over the course of billions of years from the winter of its birth in the spring of today our sun will pass into scorching searing summer as it grows to a gigantic swollen titan our world will likely not live to see that time but for the moons of the gas giants it may be a time of awakening then all too briefly the sun will pass into autumn before finally casting off its outer layers and becoming the cold glittering winter eye of a white dwarf there will be no respite from this final winter no cycle to bring renewal this winter will last until the death of matter itself except as always it wasn't that simple meteorites in the ground thought to have originated from c-type asteroids called carbonaceous chondrites had revealed traces of ammonia in their makeup ammonia is far more volatile than water its freezing point is 77 degrees colder it seems sea types didn't just originate in a region cold enough for water to condense they must have originated in a region far colder even than that much like neptune with the kuiper belt jupiter may have played havoc with the primordial asteroid belt and even thrown an entire population into it from farther out much it appeared is still to be learned by the turn of the millennium ceres had begun to take form as a unique world hubble revealed that it was spherical like a planet and also a strange pale circular feature on its northern latitudes which was rather sweetly provisionally named piazzi spectroscopy revealed that ceres's surface comprise compounds like carbonates and phyllosilicates such as mica and clay which require water to form while ceres did not undergo tidal heating like jupiter's moon europa or saturn's moon enceladus it is close enough to the sun and models suggest contains enough radiological minerals to maintain an interior of brine not only did siri show evidence of water it might very well possess a substantial reservoir today it seemed ceres just might be our solar system's closest water world in 1938 sci-fi master isaac asimov published his first short story marooned off vesta about a stranded spacecraft rupturing its water tanks to create a jet of gas that propels it toward a base on said asteroid thirty years later a junior high schooler named mark raymond read it and honored if he might have better luck if he tried it himself mark raymond was never one for existential ennui not once did he ever doubt his life's purpose by the age of nine he was already writing applications to nasa and 20 years and a phd later he was hired raymond's long journey to the asteroid belt began in 1995 when he started work on deep space 1. a nasa concept mission meant to test the feasibility of a range of sci-fi-ish concepts like artificial intelligence autonomous navigation and most importantly ion propulsion raymond had first heard of ion propulsion on star trek though he also notes it appears in star wars as well the tie in tie fighter stands for twin ion engine in real life ion propulsion isn't quite that spectacular it works by removing electrons from the outer shell of an atom of neutral gas such as xenon turning it into an electrically charged ion and then using electromagnetic fields to accelerate said ion to 40 kilometers per second which is nearly 150 000 kilometers per hour while that speed is impressive the actual force imparted by a few atoms of gas is roughly equivalent to the weight of a piece of paper but ion engines aren't about power they're about efficiency for a payload of just 30 kilograms of xenon you can get the same amount of thrust as 300 kilograms of regular propellant the trade-off is time a maneuver that a typical probe could pull off in 25 minutes would take an ion-powered craft three months this ever-present touch as light as a feather allows an ion probe to shape its orbit as keenly and as incrementally as a sculptor this additional oomph over and above that delivered by rockets or conventional thrusters gives ion-powered spacecraft a unique ability travel to multiple locations along multiple trajectories the voyagers owed their grand tour of the outer planets to a once in 150 years alignment new horizons has the advantage of traveling through a highly populated region of the solar system and so it doesn't have to alter its direction significantly to reach a new target an ion spacecraft can arrive at one destination orbit it a few times hop off to a completely different destination on a completely different flight path and orbit it as well and that's exactly what deep space one did following one of those seed of your pants mission salvaging long-distance jerry rigs for which nasa is justly famous it was able to extend its primary mission a flyby of the asteroid braille with the bonus flyby of the comet 19k morally providing the highest resolution images of a comet taken up to that time it would prove merely a dry run for what was to come by the time the images of morally were beamed down in late 2001 raymond had already pitched a new mission to nasa one for which the ion engine would be uniquely suited anyone who's seen the empire strikes back might find this hard to believe but we didn't get a close-up view of an asteroid until 1991 when the galileo spacecraft enroute to jupiter got a quick shot of the asteroid gaspara neither the pioneers nor the voyagers both of which passed through the asteroid belt saw fit to bless them with a snapshot the mission controllers were more concerned about what the asteroids could do to them but by the 1990s views were changing a recognition of their value as relics of the primordial solar system as well as the risk that they potentially posed to our planet led nasa to take asteroids seriously as mission destinations by the time raymond proposed his follow-up mission nasa's near shoemaker probe had already completed the first successful orbit of an asteroid as well as an impromptu landing the time was right for a mission to our solar system's primeval rock garden the choice of targets for the mission was a foregone conclusion series and vesta the two largest asteroids straddle the ancient volatile line preserved in the main belt ceres at 975 kilometers in diameter is not only the belt's largest object but alone comprises a quarter of its mass while vesta comprises another tenth vesta is the brightest of the asteroids and can even be seen with the naked eye under ideal conditions while vestus surface showed evidence of a lava-dominated history ceres while radially only as far from vested as earth is from venus showed every sign of continuous long-term alteration by water together they offer a perfect contrast between the scorched birth of the inner solar system and the frigid gestation of the outer raymond's vision was a true example of poetry in motion his ion-powered spacecraft appropriately named dawn would slide into orbit around vesta circle it for six months then travel halfway around the sun to series enter orbit and repeat the first craft to ever independently orbit two different objects this description will cheerfully glib does not do justice to the ballet that dawn's ion engine would allow rather than veering into orbit or arrow breaking like a common mars probe dawn would almost imperceptibly fall in a step with its target's motion entering into orbit so elegantly that a casual observer might not observe it at all so light yet so continuous was this thrust that by the time dawn was placed on its final orbit in 2018 it had spent 54 percent of its time with its ion engines active as per usual space probes dawn was cancelled three times before being greenlit shoving its construction time right into its launch period initially scheduled for launch in 2006 dawn's ion propulsion allowed nasa to shift the window to 2007 without changing the arrival date in typical nasa fashion that time was filled with an unending dog pile of checks upon checks tests upon tests proofing the hardware the software the connections the system architecture any infinitesimal thing that could conceivably go wrong once the craft was out of reach every component of the craft was duplicated often multiple times to ensure a backup should it fail every trace of any fluids left on the surface from construction had to be boiled off by heating the craft in a vacuum chamber roughly the size of a household water tank dawn is powered by two tennis court sized solar arrays which together provided 1300 watts of power at ceres's distance from the sun the power supplied not only the three thrusters but a series of scientific instruments including an infrared spectrometer a gamma ray detector and of course a visible light camera all connected to a cpu animated by 400 000 lines of code not as much as the quake 3 engine or the entire space shuttle its 100 watt antenna would send a signal to earth that would upon reception be just 1 10 quadrillionth of a watt enough to power a fridge light for one second if collected in a battery for the age of the universe each shipment of data took two days to download mark raymond surprisingly did not make the team leader or in nasa speak principal investigator though he was in the flight operations team and far more importantly for me held the exalted position of team blogger blessing me with 12 years of first-hand reports to sift through and speaking of that blog in 2006 during that frenzied rush of essential housekeeping raymond used his platform to offer this comment on sirius becoming a dwarf planet quote all scientific evidence indicates that with all the names humans have applied to them including planets asteroids minor planets protoplanets and dwarf planets they have steadfastly remained above the controversy leaving their stately lives without apparent interest of course he and his team could afford to be detached it was not their world's honor that was at stake poor alan stern as he watched his carefully laid plans for planet pluto collapse around him could not even take solace in leading the first spacecraft to visit a dwarf planet while both would arrive at their targets in 2015 dawn would beat new horizons by four months i wasn't planning to discuss the first stop on dawn's tour vesta in this video given that this is the universe of water series and vesta is on dry turns out i was hasty in my conclusion though in my defense i was not the first to arrive at it telescope studies prior to dawn had suggested vesta was differentiated with a crust of light basalt overlaying a mantle of pyroxene exposed by a massive impact density studies had even hinted at an iron core not exactly the environs in which one expects to find water planetary scientists had even identified a family of earth impactors called the howardite ukrite diogenites or heds thought to have originated from vesta these meteorites total over 350 at last count more than have been traced to mars or even the moon they are very low in volatiles suggesting that vesta is too dawn confirmed that vesta is similar both in composition and structure to the hed meteorites except four craters on vesta have shown signs of so-called pitted terrain pitted terrain is the geological equivalent of those popping holes you've seen in food left too long in the microwave impacts heat subsurface ice which in the vacuum of space immediately turns to gas and explodes upward several craters on vesta also share signs of debris flow likely triggered by liquid water volatiles detected on vesta have been associated with dark carbonaceous terrain likely the remains of c-type asteroids which suggests any ice vesta may possess is not its own after spending a year around vesta double what was initially planned dawn departed with that incident and continued its smooth journey through the asteroid belt for a further two years but of course there cannot be an interplanetary mission without the required moment of abject terror on the inauspicious day of the 11th of september 2014 less than a year before final arrival at ceres a cosmic ray likely from a distance supernova broke through dawn's defenses and hit an electrical component of the ion propulsion system when the thruster stopped dodd's computer obediently followed crisis procedure it went into safe mode used the sun to orient itself as it struggled to regain attitude control and sent out a wide beam distress call keep in mind that distress call and all subsequent data from the probe was just one ten quadrillionth of a watt and every flicker of it was crucial once they had grasped what had occurred the team solution was beautifully simple they rebooted but rebooting a computer on a spacecraft half a billion kilometers away isn't easy and took 12 anxious hours and a few minutes to midnight local time the computer successfully rebooted the thruster reignited and dawn carried on its way as dawn approached series the world's most notable feature which those peering from the ground had nicknamed piazzi resolved itself into not one but several bright features all contained within a single crater sadly for piazzi as per an agreement between the dawn team and the iau the features on series now revealing themselves to humanity would not be named for human individuals but for deities associated with harvest or for harvest festivals the crater containing the curious bright spots was named akator which means harrower one of 12 helper gods to series whose names also included plower cedar weeder reaper digger and planter no word yet as to whether any were called dasher prancer or dancer but you can never tell what a dig might turn up as dawn peered ever closer the bright spots in aquitar crater now called faculae or little torches after the bright rings occasionally found around sunspots they revealed themselves to be made not of water but of salt specifically sodium carbonate so any prospective syrian colonists out there you might consider investing in antacids the best explanation for its presence is that ceres possesses underground reservoirs of briny water either liquid or ice which when exposed to the surface by impacts evaporates into space leaving just the salt behind the most recent estimates place alcateur's age at a relatively recent 22 million years the faculae's ages are harder to determine though crater counts suggest they may have formed within the last 10 million years this subterranean water appears to be global in fact dawn's visit has shown that ceres is the most water-rich body below the frost line other than earth grande dawn's gamma ray detector which enabled the probe to detect shallow subsurface elements revealed a globe encircling water table at a depth of a few tenths of meters at latitudes above 45 degrees the water and surface regolith was just 10 by weight series also revealed that above latitudes of 30 degrees isolated patches of water ice exist on its surface often in association with craters suggesting it was uncovered by impacts evaporation of these ice patches creates a very tenuous and intermittent atmosphere around the tiny world this atmosphere is actually denser than would be expected for such sparse sources and suggests that similar evaporation might be happening all over the surface ceres also possesses lobate flows similar to glacial flows on earth as well as the telltale pitted terrain seen on vesta don's gravitational measurements suggest that series is partially differentiated with a crust rich in volatiles over a mantle of hydrated rock like clay the crust of ceres is calculated to average around 40 kilometers in thickness though it varies from 25 to 55 kilometers despite a low density which suggests a silica component of less than 20 percent ceres's crust is not believed to be dominated by water ice given the huge number of preserved impact craters which weaker ice would have rebounded back and flattened out suggesting other volatiles such as clathrates must be the main constituent this flattening has however happened to a certain extent suggesting that a global liquid layer may exist beneath the crust the surface of akitore beneath the faculae is distended by domes and riddled with fractures that suggest that salty water likely rose from the mantle possibly due to melting by impact and erupted into space before immediately turning to gas the overall composition of series's surface appears to be very homogeneous suggesting it formed from the same source which could only have been inside series the high strength but low density of ceres crust is evidence for a frozen ancient ocean if sirius has retained enough internal heat to remain a convecting mud ball quote unquote or if the surface layers provide sufficient insulation which is expected for clathrates this ocean may still persist today tantalizingly the one object in our solar system that appears to be chemically and physically most similar to ceres is saturn's watery moon enceladus for all this talk of ceres's watery eruptions it is as always important to keep things in perspective even scaled for size ceres is still thousands of times less active than earth indeed only one cryovolcano has been positively identified on its surface ahuna mans named for a harvest festival among the suminaga people of northeastern india is a tidy little thing barely four kilometers high which wouldn't make it the tallest mountain in armenia its clean slopes poked modestly above siri's ravaged surface almost as if expecting a golden-haired boy to come and sweep them out it is thought to have formed from a lava comprising a slurry of rock salt water and ice which likely rose from the mantle in a lump like a lava lamp pushing the mountain upward while ahuna is the only current cryo volcano on series the erodic corpses of 22 more have been tentatively identified suggesting that such extrusions occur about once every 50 million years before relaxing back into the crust like the moon or mercury ceres has a relatively low axial tilt just 4 degrees compared to 23 degrees for earth since it is this axial tilt relative to the sun that grants earth its seasons it seemed that ceres might have been misnamed as it lacked a seasonal cycle but in space things are almost never as they seem for one thing ceres has a temperature gradient much like earth's with its poles 50k colder than its equator how is this possible when it has no axial tilt dawn's grand instrument detected far more hydrogen and thus subsurface water near the poles than at the equator spectra also suggested that craters near the poles were coated with ice this actually makes sense again like the moon or mercury ceres's low axial tilt means that the bottoms of several polar craters never see sunlight and thus preserve ice for millennia even allowing for some light seasonal activity as the sun warms surface ice which then evaporates before freezing again on the crater walls and ceres may possess an even greater cycle models suggest that over the course of millions of years gravitational tugs from jupiter and saturn can shift ceres's axial tilt by as much as 20 degrees in as few as 12 000 years that means that over the course of millions of years ceres experiences seasons of seasons for untold cycles around the sun ceres will have no seasons at all then as its axial tilt shifts its years will become seasonal before shifting back again the world named for the goddess of the seasons has a seasonal cycle only a goddess could see but perhaps the most astonishing discovery on series was the near ubiquitous presence of ammonia on its surface ammonia cannot condense syria's current distance from the sun and so must either have been deposited by cometary bombardment which seems the most likely or in a mind-bending alternative formed with ceres much farther from the sun perhaps even beyond neptune if this is the case the series far from being the kernel around which the asteroid belt would have coalesced were it not for the bullying of jupiter may like pluto be an interloper in its own realm by february 2016 dawn had completed all its mission objectives at ceres by then it had spent nine years in space five and a half of them employing ion propulsion with which it had glacially increased its speed by nearly 40 000 kilometers per hour its two orbital missions were the first ever conducted without a preparatory flyby since its ions riot allowed dawn to do both at its lowest orbit dawn had observed sirius at altitudes lower than the international space station but no space mission can last forever and by the time dawn had reached ceres two of its force stabilization wheels had already failed in keeping with nasa tradition the team were able to improvise an alternative by using dawn's chemical thrusters as a kind of crutch unfortunately this meant that dawn's functional lifespan would only last as long as its thruster propellant by carefully conserving the last whiffs of propellant and very literally running on fumes the team were able to continue don's mission for a further two years but on the 6th of june 2018 dawn was placed in a final bolas-like orbit that swung it from 35 to 4 000 kilometers above series from which it is not expected to depart for at least 50 years in accordance with nasa's planetary protection stipulations one might argue that that is scant protection for a potentially life-bearing world-like series but to play devil's advocate it is entirely possible by then we'll have sent another spacecraft to deal with it with its earthy tones and watery depths ceres has the inviting look of a freshly tilled field waiting to be seeded analysis suggests that many of the elements needed for life carbon nitrogen hydrogen oxygen and even sulfur are present in its impact stirred soil if i might venture to channel isaac arthur for a moment with the addition of a world house the dark soil of ceres could be made to bloom and ceres could truly become the world of the harvest [Music] you

Channel: ParallaxNick

Views: 27,671

Rating: 4.9218631 out of 5

Keywords: ceres, dwarf planet, dawn mission, dawn spacecraft

Id: ExY50SQPs7o

Length: 45min 6sec (2706 seconds)

Published: Sat May 08 2021

Reddit Comments

[u/Mr-_-Soandso]

Everything on his youtube channel is worth a listen. Very informative and linguistically entertaining. I hope you all enjoy!

[u/Thatingles]

That was great. Just what I wanted for a sunday morning. Thoroughly recommend.