The Top 10 Astronomical Discoveries of 2018

[Music] [Music] hi guys I am so sorry for how long this video has taken to come out I have had the worst two months in well not in my life but certainly in my recent history I will produce a video after this is over explaining in detail what happened but suffice to say I have a new computer now and a lot of people to thank for it because I wouldn't have been able to get one on my own anywho I hope you find this year's list interesting as for last year's list this is a very personal selection and while I've tried to pay heed to what others have considered important is still very much my own opinion so hope you enjoy you [Music] water on Mars again it seems that whenever we discover water on Mars we allow to take us by surprise in actual fact we've known that Mars has water since 1956 when Gerard Kuiper caught its spectrum in the plants polar cap this year though Mars was so determined to remind us of its water that I have expected Olympus Mons to turn into Hawaii perhaps the single most nice agging reminder this year occurred in July when ESA's Mars Express which has been in orbit around the planet since 2003 use ground-penetrating radar to detect a subsurface pool of liquid water at least 1 metre deep and 20 kilometers long underneath Mars is southern polar cap now you might be thinking why didn't they discover this in 2003 well up until now evidence from the radar instrument had proven inconclusive but by way of some inventive hacking to bypass some of the onboard computers excess processing the radar team managed to jack up their resolution to the power needed to see the lake technically this is the first body of standing water ever discovered on the surface of another planet and yet in this age of plumes on Enceladus methane lakes on Titan and innumerable water world exoplanets it feels a bit late to the party in other wet Mars news this November in a paper in astrobiology Henrik Margot I and colleagues analyzed outflow channels of the Hellas Basin a gigantic impact crater that is one of Mars's defining landforms they determined that the channels must have been honed up to 34 lakes not only did these lakes have different sources such as rivers groundwater and even snow but they formed in different times across Mars as history and thus Mars must have had liquid water and surface for an extended period of time the project identified 34 potential dry Lakes one of which bears a striking resemblance to a salar a form of saline lake found in the Andes meaning Mars would have had a similar climate to a high mountainous region on earth in December Mars Express caught this image of the permanently iced Korolev crater which lies above Mars as Arctic Circle the crater named Center Gate Korolev the mastermind of the Soviet Union's early space program is exceptionally deep which means ice remains frozen longer at the bottom keeping the air above it cold this cold air then acts like a shield keeping the ice frozen year-round the cap is estimated to be about 1.8 kilometers deep making it comparable to several ice sheets on earth [Music] muah-muah you got moobs if I'd made a best of year video for 2016 Tabby's star would have topped the list you all remember tabby star that outwardly unassuming star hidden in the back waters of the Kepler catalog that turned out to have an orbiting structure so bizarre that no one could explain it well I'm afraid to say that at least in this case it isn't an alien mega-structure studies in October this year show definitively that whatever is orbiting tabbies star is blocking more infrared than ultraviolet light in other words it cannot be opaque or will be blocking all light equally and thus it can't be larger than dust particles this year the big alien kerfuffle seems to revolve around fast radio bursts but fr bees weren't discovered in 2018 and the whole et shenanigan really began brewing in 2017 no for this list I'm afraid I must hand the is it aliens metal to last year's winner Oh Moo Imola which in 2017 whizzed around our Sun from somewhere near the current location of the vagus system so fit the expected profile of an interstellar spacecraft that the current giant SETI project breakthrough listen scanned it for signals this year marco McCallion colleagues published an article in nature showing that somehow despite moving farther from the Sun omoi wa was speeding up after ruling out light pressure drag friction magnetism and geometric effects marco and friends determined that the only logical explanation was that omoi wa had to outgassed creating Jets of material that pushed it forward but there was a problem if a Mulla Mulla had outgassed then it was a comet and while it was certainly covered in enough tari carbon gunk to be a comet it hadn't demonstrated in the outgassing when it was close to the Sun when he was most expected it to in November the shmoo bialy and Abraham lobe of the Harvard Center for Astrophysics offered this in response oh ma ma could have accelerated due to the sun's light pressure provided it was less than a millimeter thick in their paper the outline that such an object despite its flimsiness could have survived any interstellar journey shorter than 10 kiloparsecs which is about 3,000 light years and then the paper achieved fame in the conclusion it stated quote if radiation pressure is the accelerating force then a Lulla Lulla represents a new class of thin interstellar material either produced naturally through a yet unknown process in the is M that is the interstellar medium or in protoplanetary disks or of an artificial origin unquote specifically the paper argues that imamova is a light sail a romantic form of spacecraft now being tested that employs light pressure from the Sun the way the sailing ships have old used wind and not only could it be artificial the paper argues it might even be deliberately targeted because to argue it was random meant that there would have to be hundreds or even millions of times more material between stars than predicted by models the paper caused a sensation scientists as you might expect reacted with some skepticism but Loeb was undeterred in a cheerful article in Scientific American Loeb argued given the technologically mature societies like ours inevitably destroy themselves Oh mwah mwah might be the broken relic of a long-dead civilization no offense meant but speaking as someone still harboring dreams for the future I hope he's wrong [Music] primordial Titans nothing in the universe astounds me more than the human capacity for boredom in the 1920s when the sheer scale and eons spanning age of the universe was first understood the shock was enough to send people like HP lovecraft screaming for the covers he and his followers and visioned increasingly vast cosmic structures beyond any human comprehension older than the earth and indifferent to men spanning the frigid black abyss in their terrifying majesty today we routinely shrug off documentaries as they insistently remind us that the Sloan Great Wall has more than a billion light years across or that Laniakea our home galaxy supercluster comprises a mass of a hundred quadrillion Suns it seems Lovecraft was wrong when he claimed that we would all go mad from the revelation of the true nature of reality we have a built-in firewall against the horror of our cosmic insignificance we ignore it which is why I like it when the door to the total perspective vortex jams open a few inches and gives our complacent brains chance to squirm one thing that most people know but don't often take on board is that when you look out across the immensity of space you are also looking back in time when you see an object billions of light-years away you are seeing it as it was billions of years ago so a telescopic image is like a core sample of the universe each farther image revealing an earlier phase of the universe's evolution and of all the elder things dredged from the Evon mists of the universe's past this year none forced me to question my own assumptions more than Hyperion from the Hubble ultra-deep field I'd always assumed that the early years of the universe where when the Lego was still just out of the box tiny malformed galaxies just waking up yet to be organized but this year volga coochie Otte and colleagues at the European Southern Observatory's Very Large Telescope and Chile identified a truly gargantuan structure at a redshift magnitude of two point four five which means it must have formed just 2.3 billion years after the Big Bang this structure dubbed Hyperion is gigantic of a mass comparable to the Laniakea super cluster thanks to the VLTs VIII maus instrument which allows for the plotting of multiple galaxies at the same time the team were able to map the object in three dimensions and they found that while big it was somewhat flabby modern super clusters are trim tight and wiry with their mass concentrated in compact nodes and sinewy filaments but this creature comprised a series of vaguely defined connected blobs of weakly associated galaxies indicating gravity had had less time to shape and sculpt it and that wasn't the only discovery made by the VLT this year in October whilst examining the Hubble ultra-deep field its spectrograph drew something beautiful out of the cosmic darkness the universe is glowing it has often been said mainly by me that the universe is what happens when hydrogen is thrown into a bucket called gravity it's a gross oversimplification of course a single hydrogen atom is already an almost incomprehensible complex structure deep enough to contain entire fields of physics one of these fields is quantum mechanics and one of the effects of quantum mechanics is the Lyman series without being too technical because I barely understand it the Lyman series is a scale of increasing frequency light flashes that occur when the electron of a hydrogen atom is excited into another level the first level is called Lyman alpha the second Lyman beta and so on the lyman-alpha emission leaves a specific mark in the ultraviolet spectrum and astronomers are very familiar with it since it occurs whenever light from the distant universe passes through clouds of hydrogen gas a fairly common event as you might imagine indeed astronomers often speak of making their way through the lyman-alpha forest one of those strikingly poetic turns of phrase that I wish scientists would make more often and this year when a team of astronomers turned the VLTs muse spectrograph toward the region of space covered by Hubble's famous Ultra Deep Field image they found the ancient galaxies aglow with lyman-alpha light it seems that in their earliest days galaxies were enshrouded by cocoons of hydrogen that their stars illumined like city lights in fog and if this light is present in the Hubble Deep Field that means it must be present across the sky hidden behind the light of more recent history a soft glow from the dawn of time another relic from the time of creation was identified in August by the Luzon polytechnics aptly named pristine survey which aims to scan the Galactic halo for some of the oldest and most metal-poor stars in the universe if you watched my video on Barnard star you'll know that metal is astronomy's for any element heavier than hydrogen and helium and that a star's metallicity is an indication of its age the older a star is the lower its metallicity and the galactic halo is home to some of the oldest stars known the ultimate dream of projects like this is to locate so-called population 3 stars stars that formed out of the primordial mist left from the Big Bang if they exist they are so far beyond our sight that they are likely to remain unseen until or unless the James Webb Space Telescope begins operations these stars are also known as mega Suns as they're pure hydrogen helium composition allowed them to grow to monstrous sizes however since large stars live fast and die young they would have barely lived a few million years before tearing themselves apart in supernovae it was the deaths of these virgin stars that seeded the universe with the material for planets soil and life pristine 221 as this relic star is known is not a population 3 star it couldn't be since once so close to our home galaxy would be long dead by now but it is the closest we have ever found it's metallicity value is minus 4 point 6 6 making it roughly 50 thousand times less metal-rich than our own Sun but what truly astounded was the stars near complete absence of carbon its carbon score was 5.6 or nearly a million times less than the Sun astronomers are frankly baffled by this carbon is one of the easiest elements for stars to create by a fusion and its presence was thought to act as a necessary cooling agent that allowed pre stellar gas clouds to calm down enough to form into stars and it isn't the only ultra carbon poor star found another ultra metal-poor star was located in November this one not in the ancient halo the relatively young disk in which our own son resides clearly there is much still to be learned here life is strange but how strange the famous assertion of Carl Sagan that we cannot be alone in the universe rests on one fundamental assumption that our solar system is normal which with a sample of one is a solid assumption to make except we don't have a sample of one anymore thanks to Kepler we now have several thousand multi-planet systems to choose from and that sample was beginning to make our solar system seem like a dowdy eccentric for instance it turns out that the familiar pattern of smaller rocky planets farther in giant gaseous planets farther out which we'd assumed would be the norm is decidedly not many caseous planets found to date are within the orbit of mercury and are known as hot Jupiters also planets and other systems tend to be the same size and evenly spaced like a string of pearls rather than exponentially spaced and of wildly different sizes as they are in our solar system this has lent some credibility to the rare earth hypothesis the idea that in order for us to be in it our solar system has to be peculiar meaning that life and a particular intelligent life is likely rare in the universe but hold on normal doesn't have to mean boring and there is no reason a perfectly normal planet can't be as lively as our own as this year proved many times in October a team led by John Michael brewer at Yale trolled Kepler data to discover that compact multi-planet systems are likely to form around low metallicity stars since planets are made of elements heavier than hydrogen and helium it had long been assumed the planets were more likely to form around younger higher metallicity stars like our own Sun except we've been finding planets around low metallicity stars left right and center and now we know that small compact systems kind of like our own inner solar system are likely to form around them which means they may not present the earliest examples of solar systems in the universe such worlds have had plenty of time to evolve maybe even to evolve life one surprising finding in the Kepler data set is the planets larger than the earth but smaller than Neptune are not only more common in that simple than planets the size of Jupiter they're also more common than planets the size of the earth these super Earths apparently absent from our own solar system unless of course planet nine in Israel are ridiculously common in the galaxy as a whole in August a team led by beat sang at Harvard used mass data from ground-based observations and radius data from Kepler to determine the densities of dozens of planets and concluded that these super Earths was radii above 2.5 times that of Earth we're likely to be mostly composed of water much like their slightly larger analogues in our own solar system Uranus and Neptune study concluded these water worlds should comprise up to 35% of all exoplanets larger than Earth but these could not be habitable surely they're liquid inner surfaces would see temperatures of up to 500 degrees Celsius while their inner core's would crush any water into exotic forms of ice well as of June this year they do have one thing in their favour it has long been thought that a water world could not possess a carbonate silicate cycle the process in which Earth stabilizes the amount of carbon dioxide in its atmosphere and ensures that it doesn't go the way of Titan or Venus but models run by Amit levy of the Harvard Center for Astrophysics have shown that if a water world is rotating at about three times the speed of earth and has a carbon dioxide level high enough the world may form a mineral rich polar cap that will rise and sink creating an analogue to the carbonate silicate cycle additionally a study of my edwin chitin colleagues found that even a water world with an ocean a hundred miles deep where water has completely cut off volcanoes from the atmosphere could still cycle carbon provided its oceans we're not too loaded with minerals that could react with carbon dioxide pulling it into the depths one of the major arguments of those in favor of the rare earth hypothesis was that plate tectonics a process so far only known on earth was necessary for the evolution of life because it maintained the cycle of carbon released into the atmosphere buried and rocked through weathering and then transported into the mantle by plate subduction only to be released again by volcanism this cycle keeps carbon dioxide levels on earth stable moderating its climate but in July Geoscience researchers Bradford Foley and Andrew sine modelled the carbon cycles on single plate worlds known as stagnant lid planets and found an alternate path to carbon cycle volcanoes on stagnant lid planets are shorter lib but unlike volcanoes on tectonically active worlds they remain in place erupting over and over on the same spot on Mars this process coupled with lower gravity has led to the formation of gigantic peaks like Olympus Mons as lava piles on lava heat and pressure increase leading to the release of co2 another rare earth hypothesis reinforced by the terrestrial planets in our own solar system is that only those who the fluid iron core could generate a magnetic field strong enough to preserve the atmosphere from the force of the Sun however this might just be a lack of imagination most of the planets interior is composed of forms of silica or rock as we call it silica is not a substance known for conducting electricity but in July Bradford Foley and Andrew sine calculated that a super-earth several times the mass of our own produce pressures and temperatures at depth great enough to slightly electrolyze silica generating a field about a hundredth the strength of iron but still capable of producing an earth-like field if the plant's rotation were faster than about two days what our little planets made of one question that has bedeviled to search for extrasolar habitable planets is where exactly the dividing line lies between a large rocky planet like Earth and a small gassy planet like Neptune in October a team led by Michael Adamski of the University of Zurich employed statistical tools to calculate the threshold radius for planets composition the team found that planets up to 1.4 times the radius of Earth could still be earth-like in composition planets between 1.4 and 1.6 Earth radii had a less dense higher silicate composition while planets above 1.6 Earth radii had to contain a substantial portion of lighter elements or ices planets above 2.6 Earth radii had to contain at least some hydrogen and helium with the amount increasing to as much as 10% at 4.30 radii which corresponds to a size and composition similar to Neptune a separate study also by lee sangun colleagues show that exoplanets did not increase steadily in size but it pronounced gaps or deserts in the determine radion particularly at two Earth radii and four s radii gap between four and ten Earth radii dubbed the sub Saturnian desert suggests that the transition point between the gas giants above and the ice giants below is very seldom inhabited the team concluded these planets below two are as radii could be called rocky those between two and four Earth radii could be called watery or icy those rare examples between four and ten Earth radii could be called transitional and those above 10 Earth radii were gas giants in February teams of astronomers at the Carnegie Institute for science tested a variant of this idea on the star system gj9 8 to 7 which happens to contain three planets just straddling the size boundary between rocky and gassy gj9 87b has a radius of one point six four times Earth's seas is 1.2 9 while DS is two point zero eight thanks to some very thorough spectrograph analyses the teams were able to constrain the three planets masses and frankly they were a bit monkey Dee's mass was determined to be about four times that of the earth which is roughly in line with his radius see the smallest of the group had amassed 2.5 times that of the earth while be at just one point six force radii was a whopping eight earth masses that meant that B had to be one of the densest planets known likely made mostly of iron d almost certainly had a gas the envelope of some kind but the team didn't observe it so remember people with telescopes the universe is under no obligation to conform to your expectations [Music] life but do we know it abiogenesis the formation of living mattered from non-life is one of the great remaining black boxes in our 300 thousand year quest to place ourselves in the universe so far we found plenty of construction material in the form of amino acids sugars and precursors to genetic molecules scattered throughout our solar system and beyond and plenty of results with the discoveries of ancient bacteria in the harshest environments of our planet and genetic mapping allowing us to trace our ancestry back to a single tiny simple cell 3.8 billion years ago but that little moment of self-organization when a bit of tar suddenly became one of the most complex machines ever observed still eludes us which means that determining how life could form on other planets requires embracing certain assumptions for example in August a team of researchers at Cambridge drawing that studies originally performed by the Medical Research Council identified a number of planets as potentially habitable based on the amount of ultraviolet radiation received from their stars in 2015 a study by the council argue that carbon from meteorites reacted with nitrogen in our atmosphere to form hydrogen cyanide which then used UV radiation from the Sun to form the building blocks of RNA widely regarded as the first genetic material the group recreated these reactions under a UV lamp and found that they produced not only the precursors of RNA but also those of lipids the building blocks of fats and amino acids the building blocks of protein it just so happens that stars like our Sun produce just the right amount of UV to power these reactions of course this might be just another bit of rare earth tera centrism the head of the group d etre kilos one of the first to astronomers to observe an extrasolar planet around a sun-like star in 1995 was careful to point out that these same reactions also occur in the absence of UV light but at a far slower rate in June an interdisciplinary team of researchers at NASA's Nexus for exoplanet system science compiled a list of likely bio signatures we might be able to detect on other planets from our own while focusing on the signatures meant for ourselves the speculation was admirably open-ended exploring ideas like alternate forms of photosynthesis particularly around red dwarf stars and the possibility of bio signatures in non oxygen dominant atmospheres but as they point out oxygen in the atmosphere remains the best biosignature by far since oxygen is so reactive that without regular replenishment from same plants it would quickly rust into the ground at least that's the theory the team did admit the free oxygen could be produced by abiotic processes such as the breaking down of co2 and water by strong sunlight in December shall her and colleagues ran experiments to see if they could recreate a series of potential extrasolar planetary atmospheres in a lab hydrogen rich water rich and co2 rich at 200 400 and 600 K and found that when exposed to simulated lightning or UV radiation several scenarios produced free oxygen on their own this does not rule out oxygen as the prime biosignature as far as I can tell no abiotic process can produce an atmosphere as rich and abundant with oxygen as our own [Music] moving it's rather strange that despite nearly 30 years of exoplanet discovery we haven't found an exome yet after all we found exoplanets the size of mercury and even EXO comets why not exomoons well this year we just might have in October geo scientist Alex teach he and David kipping reported the discovery of a large object orbiting another large object orbiting a star kepler 1625 to be exact the orbiting object Kepler 1625 B is roughly 10 times the mass of Jupiter which is why I keep referring to it as an object rather than as a planet you see according to current definitions an extrasolar planet isn't a planet if its mass exceeds 13 times that of Jupiter why this seemingly arbitrary distinction because any larger and the plant starts to fuse and we can't have that more precisely it begins to fuse deuterium a heavy isotope of hydrogen making it something not strictly a planet and not strictly a star which we call a brown dwarf so this planet may not be a planet at all but just another low mass star in a binary star system which would in turn mean that it's moon is not a moon but a planet which would be a relief because calling this monstrosity a moon violates my sense of cosmic decorum you see this moon called Kepler 16:25 b1 is the size of Neptune Moon's should not be the size of Neptune I don't want ants the size of cars and I don't want moons the size of Neptune ah but the planet is ten times Jupiter's mass well fine give it a moon ten times the mass of Ganymede or even a moon the mass of the earth I don't care just keep your neptune-sized moons away from me the odd thing here is that I know I don't know a leg to stand on the mass ratio between these two objects is almost exactly the same as that of our own insane planet and it's equally mentally ill moon Kepler 1625 is slightly larger than the Sun and it's planet or companion star orbits it roughly the orbit of Venus that means that this moon or planet is probably not in the star's habitable zone which is a shame because observations suggest that the moon or planet may have a moon moon yes that is what they're called that you could actually stand on assuming of course that it actually is a moon moon and not just you know a moon and speaking of moons that would be planets in any sane universe so much has been made and rightly so of Titans rain and flowing rivers but it is sometimes hard to remember that it is at heart a desert world the vast majority of its surface is given over to rolling coffee-colored dunes of tari sand so it shouldn't really come as a surprise that it would behave as a desert would and this year analysis of Cassini data from 2009 to 2010 near the moon spring equinox has found evidence that much like our solar system's premier desert planet Mars Titan erupted in dust storms except Titan isn't Mars its atmosphere is a hundred times denser even denser than Earth and generating dust storms require surface wind speeds five times faster than models predict exists in fact the only thing known to be capable of generating such winds would be a methane rain storm which were believed to have occurred at the same time as the dust storms so perhaps Titans and so much of a desert after all in more disappointing news in October Alma the Atacama Large millimeter array a troop of radio telescopes staring out from the driest desert on earth release the first-ever full thermal map of Jupiter's moon Europa and it was boring just a reflection back of what would be expected from albedo and surface features for a world believed to be home to a churning ocean and underwater volcanoes this was a decided underachievement another study this year found no evidence of thermal increase at the sites of possible plumes Europa when are you gonna stop leading us on and just tell us one way or the other our home gets bigger one of the few statements consistently made by both scientists in the media that I would call an outright lie is whatever you hear that such-and-such a spacecraft has left the solar system in my lifetime the voyagers have left the solar system three times once when they cross the distance to Pluto once when they reach the heliosheath the turbulent region marking the edge of the solar wind and once when they finally cross the heliopause the point lying at around 128 hue or earth-sun distances away at which the solar wind finally gives out to the winds of interstellar space many will say that the voyagers have at long last left the solar system for good do not believe them the voyagers may be outside the range of the solar wind but the solar wind does not define the solar system the Sun's gravity does and it is calculated to remain dominant over the gravity of other stars to a distance of two point four light-years the more than halfway to Alpha Centauri by the time the voyagers cross that line earth will be pointing at a new pole star I think this reticence to reveal the solar system's true gargantuan estufa public at large may be due to a desire not to make our home system or worse the amount we actually know about it seem insignificant if planet 9 has ever found you can expect that reticence to fade into irrelevance and speaking of planet 9 in October Scott Shepard and Chad Trujillo veterans of Mike Brown's epic planet quests that led to the discovery of Eris announced the discovery of 2015 PG 387 which they in light of its initials and the spookiness of the month nicknamed the goblin the goblin is truly a mooncalf of a creature with a diameter between 350 and 400 kilometers it hovers just under the boundary for sphericity and thus dwarf planet hood it is also one of only three objects known in the solar system the others being said 'no and 2012 vp1 1-3 nicknamed biden known to have a perihelion or closest distance to the sun beyond the gravitational reach of the solar system's known planets and thus no apparent origin for their gigantic orbits if you watched my video on Planet 9 you will know that it was the discovery of Sedna and its seemingly impossible orbits that led to the proposal of Planet 9 in the first place of those three paradoxical objects which the poetic Souls of the astronomical community have gained christen said no AIDS which makes them sound like benign tumors the Goblin is both the closest with a perihelion of 65 au and the farthest with a nap helium or farthest distance from the Sun of 2000 au which though far is not the farthest tip Hylian measured for any trans-neptunian object but perhaps the most notable thing about the goblin is that it fits snugly into the cloud of similar orbits first calculated by konstantin batygin that showed that something must be corralling the most distant objects in the solar system the Goblin may not prove planet 9 but its voice has been added to the ever louder call for its existence in December the same team announced the discovery of an object that was if anything even more confusing 2018 VG 18 nicknamed far-out for reasons that will soon be obvious is a pink dwarf planet sized object found at 120 au from the Sun the farthest distance at which any solar system object has ever been observed beating the previous record holder Eris by a full 25 au but as the previous paragraph hopefully made clear the fact that it is far out is not what makes this object so baffling rather it is its perihelion which is 21 a you or just grazing the orbit of Uranus how such a gigantic object could have maintained such a ridiculous orbit over the age of the solar system without being knocked out by Neptune is currently bending astronomical minds to quote Mike Brown when I asked him on Twitter but I'd say at this point we have absolutely no idea unquote to be fair far outs far in has yet to be precisely calculated so it may simply be a matter of more observation as astronomers have said since the dawn of time we shall see the final denizen of the dark edge of our solar system I would mention isn't actually a new discovery it isn't even a particularly distant object it is in fact a Platina a member of Pluto's exclusive club of Neptune dodging Kuiper belt objects what makes it so special wasn't noticed until January of this year when a team led by Wesley Frazier of the University of Belfast took multiple snaps of its spectrum and realized that while it may very well act like a Kuiper belt object it is at heart an asteroid in fact it bears a strong resemblance to c-type asteroids similar to ten hygeia and also two carbonaceous chondrites among the most primitive of all meteorites found on earth this discovery reinforces evidence found from the study of comets that the early solar system was a blender with material from the inner edge of the solar system cast to the farthest regions possibly by migrating planet this anonymous rock may be a piece of our world's original construction material you [Music] unhhhh sacred cows people tend to forget this but science isn't about what we know but about what we don't know scientists worth his or her proverbial bosons would waste time reciting facts figures and inferences drawn from them as if they were Holy Writ though this is how science continues to be taught in schools a scientist is someone who I seize facts figures and inferences like a vulture poring over them to see they still hold up and continuously prodding their weak points until they collapse this is particularly true whenever stars die and we are left to pick up the pieces of these complex the wildering events in june stephen smart of Queen's University Belfast observed we thought was a minor stellar flare in our own galaxy but then realized it could only be originated in CG CG 137 zero six eight a galaxy 60 mega parsecs or two hundred million light-years from Rome that meant it had to be very very bright the death of a giant star a supernova except it wasn't acting like a supernova supernova rise to their peak brightness over weeks this supernova called a T 2018 Co W or the cow reached its peak in a matter of days it was also ten to a hundred times brighter than a normal supernova and keep in mind that supernovae outshine entire galaxies and can be seen across the universe these are the sorts of events that astronomers live for within days 24 major telescopes were observing the cow concurrently whatever it was it was evolving too rapidly to be powered by the standard trigger of a supernova of all things the radioactive decay of nickel usually the aftershocks of a supernova are relatively low frequency pulses generated by high energy ions gradually spiraled outward by the dead start slowing magnetic field but this star wasn't going that quietly into the night the pulses remained at high frequency for weeks indicating that they must be powered by some unseen engine perhaps an accreting black hole or a raging neutron star is a speculated that this may be normal it's simply that it's usually masked by the cloud of ejecta that forms after a supernova this supernova may be the first ever seen completely stripped bare outside of our solar system there are a few phenomena in the universe more important to humanity then type 1a supernova a type 1a supernova is a stellar explosion that only occurs in systems in which a white dwarf orbits a larger star these are surprisingly common in fact the brightest star in the night sky Sirius is in just such a relationship thankfully serious in its pup are too far apart to go through this particular spat in systems where the white dwarf orbits closer in it will the creep material from its larger still living sibling piling on the pounds until it reaches the magical number of one point four four solar masses and explodes because all type 1a supernovae explode at the exact same mass point they all possess almost exactly the same brightness which is what makes them so important catching the tell-tale signature of a type 1a supernova from a galaxy far far away is one of the great quests of astronomy since because all type 1a supernovae are equally bright by measuring how bright one appears from Earth you can determine how far away it is and thus how long its light has taken to reach you and thus how old the universe is humans owe much of their current understanding of their place in the universe to type 1a supernova which is why the Ohio State University's all-sky automated survey for supernovae or assassin is making a stir this year two of the surveys targets called assassin 16 beefy and assassin 1800 H have forced astronomers to rethink the processes by which type 1a supernovae can occur and in the process complicated our understanding of where and when we are assassins 60 no H was detected in the Large Magellanic Cloud the closest galaxies visible to the naked eye and location of 1987a the closest supernova since 1604 so why didn't you hear about it well because technically it wasn't a supernova 60 no H was a super soft x-ray emission a phenomenon believed to result from nuclear fusion occurring on a white dwarf surface basically the slow roast to a type 1a is oven fire the often results in supernovae or at least in simple novi surface explosions nowhere near as powerful as supernovae but what the team was seeing was nothing like either of them in fact it was nothing like any previous super sub x-ray emission its point of origin was far smaller than the surface of a white dwarf and it displayed none of the phenomenon secondary signatures they concluded that the emission had to be formed by some new process possibly accretion all heat but not directly tied to a future title in a supernova this meant that there is more than one way to produce a supersoft x-ray emission and thus that our understanding of the finer processes underlying the formation of type 1a supernovae is incomplete not a game-changer perhaps that a reason to be vigilant if type 1a supernovae are lights into the universe then it helps to see them in high-res as such one of the prime goals of astronomy is to catch a type 1a supernova in the act so that the finer details of the event can be properly scrutinized and that's exactly what happened in February this year thanks to assassin 18 BT the first type 1a supernova confirmed from the Kepler data set unlike 1608 18 BT is not nearby in fact its distance from Earth is a full 53 mega parsecs in an old dwarf galaxy named UGC 0 4 3 7 8 0 thanks to a confluence of well-known telescopes including the Keck pan-starrs Atlas and a host of others the team were able to catch a strange additional emission as the white dwarf gathered itself for its big moment attempts to explain this emission have failed to account for everything observed it may be yet more evidence for an idea that has been gaining ground for the last few years that there are two different types of type 1a supernovae will we have to rethink one of the most cast-iron methods and an astronomers toolkit it's unlikely that these two populations have vastly different origins but we will still have to take them into account as we attempt to map the universe [Music] you Barnard's star bee I already made a video about that so let's look at some other exoplanets first let's look at CI Tory B and yes I'm aware that that sounds like the title of a Disney Channel cop show just go with it CI Tory B was actually found a few years ago but caused such a stir that this year a team of Cambridge astronomers using the Atacama Large millimeter Array or Alma decided to look at it again and what they found only made it weirder CI Tory B is a hot Jupiter a giant jupiter-like planet orbiting its star at distances closer than mercury is to our Sun this in itself is nothing strange at least not these days hot Jupiters form the majority of the first planets found around for using stars except that CI Tory is a t-tauri star that's just a coincidence the type specimen of the star happens to be in the same constellation a t-tauri star is a very young star that is not yet contracted to the point of fusion basically a baby stars are believed to remain in this state for just two million years far shorter than the three to ten million years predicted for gas giants to form also hot Jupiters are supposed to form farther from their stars where material is more plentiful and then migrate inward to their current positions a remarkable feat to accomplish in less than two million years Alma's finding this year only added to the confusion like all young stars CI Tory is surrounded by a circumstellar disk a ring of dust about as wide as the distance to Pluto that is in the process of being cleared into planets within this disk the Alma team identified three large gaps likely the cleared neighborhoods of three young planets to roughly the size of Saturn one roughly the size of Jupiter one giant planet around such a young star was weird enough but for spec's have worked from earlier this year that shows that planet formation begins even before a star is fully formed it's possible the other planets may have played a role in pushing c---eight or EB to its current position but as yet the mystery of the system remains unsolved 20-18 also brought a host of new results concerning Trappist one the goldmine system of seven earth-like planets found in february of last year in january a paper by amy c bar and colleagues determined that with the exception of see the densities of every one a Trappist worlds are low enough for water to comprise a vast portion of their makeup likely meaning that they have oceans hundreds of miles deep B and C are close enough to their star to experience intense tidal force meaning that they likely experience vast amounts of volcanism but even de and F experience tidal forces 20 times higher than Earth it concluded that planets D and E are the most likely to be habitable assuming they can avoid runaway greenhouse effect in February a further series of results derived an approximation of their masses from their gravitational effects on each other this allowed astronomers to attain their densities which suggested the plants were mostly made of rock and the water made up around 5% of their mass still an astronomical amount compared to earth 0.2% but less than the 50% predicted by some other models the study showed that B and C are likely to be similar to Venus baked hel world's while D is estimated to have only 30% the mass of Earth and thus is unlikely to possess a special atmosphere again it seemed Trappist 1e e appears to be in size density and solar influx the closest to Earth but in a system like Trappist 1 as the paper published in October noted habitability is not as strict as it would be in our system because given the Trappist planets proximity to each other it would be easy for life that formed on any one of them to travel to and infect the others in November however a team from the University of Washington constructed a climate model that suggested that with the exception of Trappist 1ee all the planets in the Trappist system were either hell worlds like Venus or frozen like Mars of course none of this is known for certain we'll have to wait for the James Webb Space Telescope to tell us more finally I'd like to end on an exoplanet of no significance whatsoever except perhaps for me 40 rittany is a three Sun system located 16 light-years away from Earth its main star now called key by the grace of the IAU is a k-type dwarf slightly cooler and older than our Sun orbited by a white dwarf and a red dwarf and it was this system the Star Trek creator Gene Roddenberry ultimately chose as the home system for the planet Vulcan he originally favored the better-known Epsilon Eridani but backed away upon learning of that stars relative Hugh I'd like to say that the discovery of a planet around for Tierra de announced this year is a step in the path to fulfilling my childhood dreams but unfortunately for Tierra de a B is a gigantic super-earth eight times Earth's mass in a roasting 42-day orbit that makes Mercury's look sluggish that doesn't preclude the possibility of another planet farther out of course so fingers crossed gotta say the Vulcans do exist they must get some fantastic sunsets [Music] [Music] [Music] you

Channel: ParallaxNick

Views: 75,779

Keywords: top 10 2018, top 10 astronomy, top 10 astronomical, water on mars, 'oumuamua, oumuamua, ancient galaxies, pristine 221, hyperion, abiogenesis, GJ9827, exomoon, moonmoon, kepler 1625b, kepler 1625b I, titan storm, titan dust storm, 2015 tg387, the goblin, 2018 VG18, farout, kuiper belt asteroid, AT2018cow, the cow, cow supernova, trappist-1, 40 Eridani, vulcan

Id: MKjaOLPGAyA

Length: 50min 26sec (3026 seconds)

Published: Fri Mar 29 2019