A Journey to our Closest Galaxies

mankind has always been trying to get to the bottom of the nature of things around us and while there were times when people used to struggle to define the laws of classical physics scientists of the 21st century are busy solving comparatively more sophisticated and challenging tasks thanks to the joint efforts of scientists of all times there is an impressive list of scientific discoveries to mankind's credit and now the acquired knowledge allows us to take a peek at the most mysterious corners of the universe today i invite you on a tour around our closest galaxies but before reaching those we will stop the dwarf planet makimaki and the trans-neptunian object sadner talk about the weirdest objects ever to have approached our earth venture to the most horrifying exoplanets and fly by the star known as wr 102 a great trip is about to begin let's get started [Music] cosmo the first in outer space it was pluto that was the first astronomical body discovered beyond neptune's orbit it happened over 90 years ago back in 1930 unfortunately the technologies of the day were not advanced enough to be able to detect dim objects at large distances that is why it took another 47 years before another discovery of a celestial object in that area of space had been made in 1978 sharon was discovered and the first asteroid beyond pluto's orbit albion was detected in 1992 the 1990s proved to be fruitful in terms of discovering a string of transneptunian celestial bodies but at the beginning of the 21st century there was a positive boom in exploring remote parts of the solar system that is when the prominent team of researchers michael brown david rabinowitz and chadwick trujillo pinpointed the most well-known space objects beyond neptune's orbit among these one designated 2005 fy9 can be singled out later on it was to be renamed into makimaki this exoplanet was first seen in images taken on the 31st of march 2005 and four months later on the 29th of july information about the newly discovered celestial object was made available to the general public after the official statement from the research group when discovered the planetoid was just slightly dimmer than pluto as for its location at the time it was much higher than the ecliptic plane in the region of the constellation comaberanises thanks to archive images makimaki has been thoroughly studied by now the planetoid's eccentricity isn't big at just 0.162 the angle between the planetoid's orbit and the ecliptic plane is 29 degrees which is why this object bright and large as it is hadn't been noticed before when exploring those parts of our system the first researchers had focused on the ecliptic plane as they assumed that the chances of discovering new celestial bodies there were higher at the time however the planetoid was located in the upper part of its orbit which is why the researchers couldn't see it makimaki completes a full orbit around the system's center every 306 years it is currently 52.5 astronomical units away from the sun the planetoid is going to reach its aphelion in the year 2033 with a distance to the sun 52.82 astronomical units having receded from the parent star and reached its furthest point from it makimaki will start approaching it the planetoid is estimated to reach its perihelion in the year 2187 with the distance separating it from the sun being 38 astronomical units at that point on the planetoid's closest approach to the system's center its luminosity will be almost the same as that of pluto which will enable scientists to collect more accurate data about it in terms of its orbit's parameters the dwarf planet falls into the category of the so-called classical objects of the kuiper belt or qbino unlike plutinos which are in orbital resonance with neptune qbinos lie quite far from this icy giant that is why the gravitational influence exerted by neptune over them is quite negligible on the 23rd of april 2011 makimaki's disc was passing in front of a dim star in the constellation coma berenices thanks to this eclipse it was possible to estimate the planetoid size rather accurately its equatorial diameter measures one and a half thousand kilometers its polar diameter on the other hand turned out to be one thousand four and kilometers which is around 62 percent that of pluto this earns makimaki the status of the fourth largest transneptunian object coming after pluto aerys and haumea however it may still be beaten by gong gong whose parameters still haven't been estimated with a satisfying degree of accuracy makimaki's exact mass still remains to be found out the planetoid's average density is estimated at approximately 1.7 grams per cubic centimeter which is slightly lower than that of pluto this information allows us to gauge the dwarf planet's mass at roughly 3 times 10 to the power of 21 kilograms incidentally it is four percent that of the moon makimaki's rotation period is around 22 and a half hours which is quite a lot for a dwarf planet it is known that the planetoid faces the earth with its equator although the tilt of its axis with respect to the orbital plane hasn't been estimated yet makimaki is admittedly a rather bright object the average ratio of its actual brightness equals around 0.8 first spectral analysis revealed that the planetoid surface is not homogeneous most of it shows a high brightness ratio reaching ninety percent still up to seven percent of the dwarf planet's surface is dotted with dark spots absorbing up to 98 percent of the light shed on it these patches are thought to be areas of surface made up of rocks that are peculiar to the planetoid strangely enough later observations carried out using the galileo national telescope showed makimaki's surface as rather homogeneous the dark spots reportedly seen on it may have been areas of observation or reflections of an unknown satellite that happened to be passing over the dwarf planet's surface that is why further observations are needed to settle the question observations and spectral analysis revealed that makimaki's surface is almost as bright as that of pluto it consists for the most part of methane ethane and a very small amount of nitrogen continuous exposure to powerful ultraviolet rays is thought to have produced thorolins complex hydrocarbon polymers containing nitrogen it is thorolens that give methane snow on the surfaces of objects a typical reddish hue makimaki's surface temperature is currently estimated at around 29 kelvin or 244 degrees celsius below zero when makimaki is in its perihelion the temperature slightly rises to around 34 kelvin or 239 degrees celsius below zero as the melting point of nitrogen and methane is much higher it is logical to assume that the planetoid must be covered with reddish snow made up of methane mixed with ethane nitrogen and tholins interestingly observations and estimates show that methane on makimaki's surface is crystallized and appears as rather large grains around one centimeter in size as for ethane it looks like grains measuring around one millimeter in diameter and filling smaller crevices and holes on the planetoid it goes without saying that in such low temperatures machumaki's atmosphere is bound to be extremely rarified the density of gases just above the planetoid surface is approximately one billion times as low as that on our earth the eternal ice the surface is encased in cannot melt even on the planetoid's closest approach to the sun [Music] besides most of the solar energy reaching the dwarf planet rebounds back into space on account of the object's high albedo for a long time it was thought that makimaki didn't have any satellites however in 2015 a group of american researchers did detect a celestial body orbiting the planetoid that's when its main parameters were gauged the object hasn't been given a name yet and for now is officially catalogued as s 2015 still the satellite was informally nicknamed mk2 as usual a quick overview of the basic parameters to begin with mk2 is a small and dark celestial body that reflects around seven percent of all light shed on it its diameter may measure anything from 90 to 200 kilometers and the radius of its orbit cannot be less than 21 000 kilometers as for its orbital period it is around 12 earth days the inner makeup of mk2 is thought to be identical to that of makimaki however sun rays would have vaporized the layers of methane snow that used to cover its surface besides with almost no gravitation forces exerted by the satellite to speak of the gases molecules would have floated away into space it is admittedly an extremely slow process that takes billions of years to complete as makimaki's rotation period is anomalously long it gives grounds to assume that there is at least one more large satellite orbiting it but it still remains to be discovered makimaki is currently located almost to the furthest point of its orbit which makes it difficult to investigate it however sending out an interplanetary space probe to explore it is hardly sensible at this point estimates show that it will take the spacecraft around 16 years to reach the planetoid even taking into account a gravity boost maneuver near jupiter just in 150 years mere seconds in astronomical terms makimaki will be closer to us than pluto even though it will take a while sooner or later it will certainly reveal its secrets to us in the late 20th century there was a major breakthrough in studying remote corners of our solar system 3555 celestial objects have been discovered beyond neptune's orbit since the 1990s most of them are not very large bodies made up of water ice and frozen gases like methane and nitrogen trans-neptunian objects form conventional areas around the sun like the kuiper belt the scattered disk and supposedly the oort cloud the kuiper belt encompasses the solar system as a large ring at distances from 30 to 55 astronomical units from the center it resembles the asteroid belt only it is 20 times as wide and up to 200 times as massive the kuiper belt consists mainly of debris remaining after the formation of the solar system although it does contain rather large objects as well like pluto sharon haumea makimaki and other planetoids the borders of the scattered disc are more blurred it consists of objects whose perihelion is over 35 astronomical units and whose orbits are elongated or lie closely to the ecliptic plane most of these objects are not very large and are quite gravitationally unstable most of the scattered discs objects orbits are posited to have been predefined by neptune with the latter having expelled them from the inner layers of the solar system acting as some kind of a gravitational cannon the largest space object in this area in space is the planetoid eris there is one more object worthy of our attention it's a small planetoid called sedna that's what we'll talk about today this dwarf planet was discovered on the 14th of november 2003 by american astronomers michael brown chadwick trujillo and david rabinowitz at the time of discovery it was thought to be the second largest object of the kind beaten only by pluto however very soon it found itself in the fifth place among all known transneptunian objects coming after eris haumea and makimaki as revealed by calculations of sadness orbit around the sun its trajectory is extremely elongated its perihelion is 76 astronomical units which is two and a half times the radius of neptune's average orbit sedna's aphelion is 942 astronomical units away from the sun thus the planetoid must be one of the remotest and apparently the coldest objects in our system detected so far that is actually what has earned it its name one of its discoveries michael brown has dubbed it after an inuit goddess of sea animals sedna completes a full orbit around the center of the solar system within approximately eleven and a half thousand years when discovered it was 89.6 astronomical units away from the sun this is approximately twice the distance to pluto sadly is now on its way to meet the sun it is expected to reach its perihelion around the year 2076 however the sun will not be visible as a disk from the dwarf planet's surface even from the closest point of its orbit when watched from sedna our sun will look like a very bright star with a luminosity much higher than that of the moon in our sky sedna's diameter is about a thousand kilometers it is only forty percent that of pluto and slightly smaller than sharon unfortunately there are no moons around sedna that is why it is hardly possible to gauge its mass with a high degree of accuracy as it is it is estimated at one to ten percent that of our moon in plain exact numbers it could be anything from 8.3 times 10 to the power of 20 kilograms to 7 times 10 to the power of 21 kilograms only a special expedition to the dwarf planet's environs would yield much more precise data [Music] sedna's rotation period is about 10 hours with a rotation axis tilting to the orbital plane at almost 12 degrees the planetoid's bright red surface reflects around 32 percent of the light shed on it spectral analysis shows the dwarf planet's outer layers are mostly made up of water ice and frozen gases methane ethane and nitrogen prolonged ultraviolet radiation treatment of the hydrocarbon sludge on the surface produced phthalins organic polymers containing nitrogen it is these substances that give the planetoid surface its bright color sedna will be comparatively close to the sun for about 200 years in this time its surface temperature will rise to 35.6 kelvin or 237.6 degrees celsius below zero this will make some of the gases shrouding the planetoid evaporate which in its turn will greatly rarify the atmosphere however the most optimistic estimates show that its density will be 70 000 times less than that of the earth at the very least when the planetoid hits the escape trajectory from the sun its temperature will rather dramatically fall to a few degrees above absolute zero it is thought that unlike on triton pluto and darius there are no methane snow precipitations on sedna on account of its low temperatures even though sedna was discovered almost 30 years ago scientists still don't have a unanimous opinion about it one of the things on which they don't agree with each other is where it belongs that is whether it is part of the scattered disk or the oort cloud [Music] the oort cloud is a hypothetical area in the solar system lying beyond the scattered disc and stretching for up to a hundred thousand astronomical units away from the sun its borders are rather blurred this part of the solar system looks like a spherical cloud made up of a great number of comet nuclei it is from here that comets with enormous orbital periods of tens of thousands of years take off as it were the hill sphere or the sun's gravitational sphere of influence is considered the cloud's outer boundary the sphere's radius is about one light year sedna's orbit is so elongated that as it travels in the solar system it traverses the entire area of the scattered disk and approaches the inner boundary of the oort cloud some scientists believe that the object is too far from the main planets in the solar system and so their gravitational pull is negligible besides sedna was estimated never to have come close enough to neptune to have had its orbit in any way affected these clues lead us to believe that sedna is much closer to the oort cloud objects even though most of its orbit finds itself within the scattered disk as sedna is remote and barely studied there are theories awaiting further confirmation for example modeling the process of radioactive decay suggests the possibility of there being a liquid ocean in the planetoid's interior calculations of the trajectories of several transneptunian objects with elongated orbits including sedna give grounds to believing that there is an undiscovered massive object located beyond the boundaries of the kuiper belt data collection is underway and its results will either confirm or repudiate these assumptions even though sedna is listed in nasa's programme of the solar system exploration no spacecraft is planned to be sent to it in the nearest decades perhaps it'll be paid due scientific attention when the distance between the dwarf planet and the earth is considerably smaller sedna may well be a really remote celestial object but there are some even further than that out there in the solar system for example the object 2018 ag-37 also known as far far out was spotted 132 astronomical units away from the sun it is the remotest object in the solar system that can be observed directly interestingly while following their orbits some celestial objects already known to us may recede from the sun much further for example the aphelion of the comet c1992 j1 spotted by david rabinowitz in 1992 is 3650 astronomical units this means that it will take 78 000 years to complete a full orbit there are many comets of this kind with elongated orbits and a mind-boggling orbital period that are still waiting to be discovered who knows one of you might be able to do that at some point generally speaking celestial bodies with such parameters fall into the category of interstellar objects interestingly they're usually not gravitationally dependent on any star and are quite free to choose their own course in theory such space wanderers may come from asteroid belts of other stellar systems and then after they collide with a larger object their orbits may change this makes them break away from their native systems the same mechanism of producing interstellar space objects is applicable to our system too the greater number of bodies from the old cloud and the kuiper belt eventually end up in interstellar space bearing this in mind it seems reasonable to assume that there is a much greater number of objects in our system that originally come from somewhere in deep space than thought earlier for example on rare occasions interstellar interlopers may be captured by the gravitational pull of a larger celestial body then they may be influenced by the sun's gravity that will lock them on a heliocentric orbit the only closest planet able to perform this on account of its impressive mass is jupiter it is in the environs of this gas giant that a comet can be found which is one of the most unusual short period comets ever detected in the solar system spotted on the 12th of may 1986 the comet was dubbed 96 pm mack holds one the object's peculiar characteristics are its most unique features to start with the comet's orbit is exceptionally elongated which allows it to approach the sun as close as .123 astronomical units just to compare this is two and a half times smaller than mercury's perihelion its chemical composition is another of its unusual characteristics it contains 72 times less cyanogen than any regular comet these properties give astronomers grounds to suppose that mcholz1 was born far away from the boundaries of our system having been captured by jupiter's gravity it was indeed brought into heliocentric orbit nevertheless mack holtz one remains a hypothetical interstellar interloper whose origins are in essence quite untraceable today meanwhile there are thousands of comets and asteroids already known to us and among them there are some astronomical bodies that have arrived to our system comparatively recently one of these is the comet known as 2i borisov whizzing through our system at 30 kilometers per second this object is gravitationally independent from the sun the comet 2i borisov is likely to have set out on its long journey from the cassiopeia constellation near the border with the perseus constellation there are several points in space that claim the title of the comet's parent stellar systems ros 573 gj4384 and hd 34327 as for the comet's characteristics that have been found out so far its diameter measures 20 kilometers and its orbit is hyperbolic at the same time the comet's spectrum is very similar to that of most other comets in the solar system the celestial object is consistently observed two consecutive flares were registered on 2i borisov in early march 2020 by astronomers from the ogle project team the processes suggested by these telltale manifestations are indicative of an explosion in the comet's interior with a large fragment ejected as a result however nothing is known about what happened to the newly formed chunk even in spite of the uniqueness of the comet 2i borisov it is quite logical that such like celestial objects do exist sooner or later an object like that was supposed to pass through our system but it is hardly possible to say so about another celestial body we'll be looking at namely about the first interstellar asteroid ever detected dubbed omo amur the asteroid was detected on the 19th of october 2017 by the canadian astronomer robert werwick the object was 30 million kilometers away from the earth at that time at first omuamur was mistaken for a comet but later it was reclassified as another kind of celestial body a hyperbolic asteroid it is highly likely that the starting point for the object's travels was an environs of the vegas star and then it set out towards our system following a hyperbolic trajectory and moving at a speed of 26 kilometers per second scientists cannot say how long aomo may have been racing through interstellar space and for all we know the solar system may be the first planetary system the asteroid has visited after its ejection from the parent system the object is posited to consist predominantly of rock and its diameter is estimated at approximately 200 meters being cigar shaped the asteroid may rightfully be called one of the most elongated objects in the solar system according to the astronomer david jewett it is a shape that mainly draws scientists attention the reason for that is that a celestial object with such peculiar looks must have some unique story of its origin having formed either as a result of a destructive event or else artificially for example at some point of its existence omuamua may have been a shard of a protoplanetary body with the latter having approached its native star too close and ultimately having been torn apart by its tidal forces computer modeling of such events revealed that there is a large celestial body within several hundred thousand kilometers from its star it may really be destroyed under the influence of stellar tidal flows this makes it disintegrate into exceptionally elongated bits whose kinetic energy allows them to leave their system this event is thought to have happened approximately 45 million years ago this spurred some scientists to put forward another hypothesis they maintained that in theory this object might actually turn out to be a spaceship constructed by an alien race to futurologists deep regret astronomers closed the case in 2019 proving once and for all that there is absolutely no evidence in support of the hypothesis that omuamua was created artificially at the moment the asteroid is on an escape trajectory from our solar system heading towards the pegasus constellation the velocity at which it is racing away from the sun has proved to be slightly higher than had been predicted by applying celestial mechanics laws the value reached around 31.6 kilometers per second on the 1st of june 2018 hypothetically it will be possible to send a mission to this asteroid this would allow us to find out more about its properties however no existing spacecraft would be able to catch up with omuamur as the speed at which it is streaking through space is too high in theory it is feasible to get close to the asteroid after a gravity boost maneuver performed near jupiter and thanks to the oberth effect which is supposed to greatly boost the engine's acceleration more advanced options for the purpose are considered as well among these scientists suggest using a laser pushed light sail based on the breakthrough star shard technology however it should be noted that the main challenge that will have to be tackled in the course of the missions will be to reach the asteroid in as little time as possible while at the same time to be able to collect valuable scientific data if on the other hand the spacecraft accelerates too much it will not go into omar moore's orbit and will simply whip past it and fly on and so today investigating the asteroid with the help of spacecraft remains just a theory if a mission of this sort does get launched sometime it is hard to imagine what secrets lurking in the celestial body may be revealed to us having negotiated millions of kilometers on their travels objects like omuamua are bound to be sources of staggering amounts of valuable information no one can tell what events they may bear traces of in addition to that interstellar interlopers may in theory turn out to be the carriers of varieties of matter which are unknown to us if mankind is able to reach the surface of one of these objects a mission like that might well find answers to many questions about these mysterious celestial travelers shortly before halloween in 2020 nasa compiled a list of the most terrifying worlds among others they included six exoplanets each of these objects environments is not just extremely harsh for any living organism even finding oneself in their comparatively close proximity may prove to be fatal the first object on the list is a black gas giant designation tres 2b this celestial object orbits the star tres 2 which is a yellow dwarf lying as far as 718 light years away from us let's take a closer look at it due to some unique properties of the chemical composition of the surface of tres 2b the planet absorbs over 99 percent of all the light shed on it the nature of these properties remains a mystery and chances are there are some chemical reactions taking place on the surface that we have never registered on any similar object before and it is these properties that make tres 2b the darkest exoplanet on the astronomical map of today this gas giant was discovered on the 21st of august 2006 with more details on its characteristics obtained several years later the mass of tres 2b is 1.2 jupiter masses and its radius measures 1.27 times that of jupiter the atmosphere is as scorching as 1000 degrees celsius which gives the exoplanet a faint red glow like that of ambis still in spite of its gloomy looks tres 2b doesn't really qualify to be called the most dangerous place in the universe there are many more objects lurking in space that are more terrifying than that let's see some more inhospitable ones here is another exoplanet designation 55 cancri e it lies in the system of a sun-like star designation 55 cancri a this celestial object was discovered on the 30th of august 2004 by the doppler spectroscopy method let's look at it in more detail the planet's mass equals approximately 8 earth masses and its radius measures 1.875 that of the earth 55 cancri e is tidally locked and so it is always daytime on one side and night time on the other that is why the side facing the host star is always heated up to a temperature reaching 2400 degrees celsius with the temperature on the night side 1300 degrees celsius these values are so high because the distance between the planet and its parent star is just 0.0183 astronomical units besides volcanism on 55 cancri e which is thought likely to be there causes dust clouds emissions these clouds trap hate and effectively prevent it from escaping into space the planet's orbital period is slightly under 18 hours as for the atmospherical makeup there is helium and hydrogen registered in it there are also large amounts of carbon incidentally this element is likely to form thick layers of graphite and diamonds in the planet's interior 55 cancri e isn't the only object in the planetary system of its host star there are four other celestial objects orbiting it the environments on these are by far more hospitable which is the feature by which the 55 cancri a system differs from the following object it is dubbed poltergeist or psr 1257 plus 12c this is an exoplanet lying in a pulsar system the celestial object is located just 0.36 astronomical units from the system's center this shows that poltergeist wouldn't have survived a supernova that must have taken place before the pulsar had been formed consequently the exoplanet is likely to have formed after this tremendous event with the material for it coming from the nebula left after the explosion according to another hypothesis the pulsar may have formed after the merging of two white dwarfs unlike with a supernova this process isn't always accompanied by a powerful blast still as this is the first object of its kind we have discovered science cannot give a definite answer as to its origins the system with a celestial object lies 2 300 light years from the earth its mass is approximately four times that of our planet as for its orbital period it is around 66 days incidentally the outstandingly powerful radiation emitted by the pulsar is enough to crumple any spaceship wanting to approach the mysterious exoplanet in its system even with all these properties taken into account portuguese does not really qualify as the most dangerous exoplanet known to us on approaching it an astronomical body may simply get destroyed but it would get positively vaporized in close proximity to the following object the reason for this effect is the extremely high temperature on kepler-70b which is the hottest exoplanet known to us the object orbits the sub-dwarf star kepler-70 with a surface temperature higher than that on our sun it reaches 6800 degrees celsius the object's mass equals 0.44 earth masses and its radius measures 0.76 that of the earth the celestial object's orbital period is 345 minutes in other words a day here is less than 6 hours long interestingly the exoplanet regularly passes another object in the system kepler-70c at a distance of 240 000 kilometers to date this is the closest that planets in space have been registered to pass each other the extremely high temperature on kepler-70b could be accounted for by the fact that this object may once have been part of its parent star as for giving it the status of an exoplanet it will take more evidence to confirm that it deserves to be given it so this remains an open question it should be mentioned that kepler-70b is not the only celestial object we know of that interacts with its parent star so closely another object in similar conditions is the exoplanet known as wasp 12b this celestial body lies 870 light years away from our system its radius measures 1.93 times that of jupiter and its mass equals 1.46 jupiter masses wasp 12b is just 0.03 astronomical units away from its parent star due to this close proximity the exoplanet has a temperature reaching as much as 2200 degrees celsius the host star's extremely powerful gravitation slowly absorbs wasp-12b eventually in approximately 10 million years time the exoplanet is expected to be destroyed completely bearing all this in mind we will probably never delve any deeper into the nature of this exoplanet it would appear that studying worlds of this kind cannot be high on scientists list of priorities however some of these objects may happen to have some really unique features seemingly quite plain and ordinary worlds like that may conceal many more dangers than would appear at first glance when flying past the celestial body hd189733b for example one might complacently think it a safe planet as it resembles our earth by its looks but if one were to get as low as the level of its atmosphere one would be exposed to some life-threatening dangers for a start the object's winds carry particles of silicate and develop velocities of 8 700 kilometers per hour besides the rains on this planet cause precipitations of molten glass the reasons for such hazardous weather conditions are extremely high temperatures and the atmosphere's peculiar chemical composition speaking about the exoplanet's orbital period it is approximately 2.5 days and it is highly likely that the object is tidally locked to its parent star [Music] as usual a quick overview of its main characteristics hd189733 is a bright blue gas giant orbiting an orange dwarf in the constellation vulpecula it lies just 63 light years away from our system the object's diameter is 1.1 times that of jupiter and as for its mass it is 113 percent that of jupiter interestingly the distance between hd189733b and its star is 30 times less than the distance between the earth and the sun and equals approximately 5 million kilometers due to its close proximity to the parent star it has a constant surface temperature of as high as around 930 degrees celsius on the dayside with the temperature on the night side never dropping below 425 degrees celsius immediately on being discovered the celestial body became a subject of investigations in 2007 thanks to data obtained by the hubble telescope scientists found out that hd189733b has a foggy atmosphere interestingly when the planet transits between the observer on the earth and its star its atmosphere assumes a reddish hue this effect could possibly be caused by the haze in the atmosphere according to preliminary estimates it consists of particles of iron silicates and aluminium oxide apart from that the information beamed back by the hubble telescope helped scientists establish that the planet's atmosphere contains water vapor neutral oxygen and an organic methane compound additional investigations revealed the presence of carbon monoxide on the day side of the planet what prompted most questions however was the results of investigations revealing traces of methane of an unusual variety in the planet's atmosphere this chemical element was shown to be in a peculiar fluorescent state when it emits electromagnetic radiation in the infrared range this state of the substance is indicative of some unknown activity in the atmosphere of the exoplanet which still remains to be found out this is quite a clear-cut example of a situation when investigating an object like an exoplanet with an exceptionally harsh environment may yield unexpected results about some processes taking place there that will be a valuable contribution to science and as the process of studying these worlds continues they will remain no other than horror planets to us as well as a solid reminder that we're more than just lucky to be the dwellers of our earth temperatures of any star's interiors are incredibly high it is hardly surprising as thermonuclear synthesis that is the main energy source of all stars can take place only in these extreme conditions when two atoms of hydrogen merge they produce an atom of helium and release an electron and several neutrinos in addition a great amount of energy is released during the process still the hydrogen helium synthesis isn't the only process that heats up stars at higher temperatures other elements may take part in chemical reactions as well for example lithium carbon or oxygen in this case cause of heavier elements are produced such as sulfur magnesium or phosphorus their charge is higher and they repel each other more robustly much more energy is needed to overcome this resistance when a main sequence star depletes most of its hydrogen supply it starts to expand and cool off with time it ends up as a red giant it will continue to burn due to thermonuclear reactions of helium transforming into carbon and oxygen the lighter the star however the less time it will continue to burn eventually becoming unstable it sheds its outer layers and goes supernova this leaves it a white dwarf with no resources to fuel any thermonuclear reactions anymore with all its energy sources depleted it is forced to gradually cool off interestingly when the mass of a star is higher than a certain value heavy thermonuclear synthesis may become the star's main energy source even after all hydrogen has been used up such celestial objects are referred to as wolfray at stars this class of space objects was discovered back in 1867 by the french astronomers charles wolf and george reyette the scientists attention was scored by anomalously bright emission lines of heavy elements in these stars spectra as for the inner makeup of these unusual celestial objects it was accounted for much later stars of this class are generally heavy they have quite a meager supply of hydrogen and are in the final stages of their revolution wolfrey had stars are extremely rare to date just a few hundred of them have been discovered in our galaxy as for their overall count in the milky way it is estimated that there can't be over two thousand celestial objects of this class wolf read stars are subdivided into three main sequences depending on the prevalent elements in the spectrum nitrogen carbon and oxygen sequences each of them in its turn is subdivided into several types as for the hottest star in the studied universe it falls into the category of the oxygen spectral sequence ones the celestial body which is now known as wr102 was discovered back in 1971 at first it was mistaken for the optical counterpart of the x-ray source gx3 plus one however further observations revealed that there were two completely different objects according to data acquired thanks to spectral analysis the discovered star had unusually bright oxygen lines in its radiation spectrum thus in 1982 wr102 and four more bright stars became the first to form a new class spectral analysis showed that the star's surface temperature reaches over 210 000 kelvin this makes wr102 approximately 36 times as hot as our sun the luminosity of the scorching hot object is unbelievable it is estimated at over 380 000 times that of the sun wr 102 lies about 10 000 light years away the star is located in the part of the sky with the constellation sagittarius incidentally in spite of its exceptionally high luminosity it can't be seen with the naked eye as it is too far away from us wr-102 currently belongs to the extremely rare star class wo2 containing great amounts of oxygen and almost no hydrogen it mainly relies on the merging of heavy cores of such elements as neon carbon and oxygen as its sources of energy to date only nine objects of this class have been discovered with four of them located in the milky way and the other five in other galaxies there are two factors that make oxygen spectral sequence stars rare firstly there are very few of woolfreyad's stars around because only stars were the mass not less than 40 solar masses are potential candidates to become ones secondly this class represents the final stage of evolution of stars of this type the stage may last anything from a thousand to ten thousand years which is mere seconds in astronomical terms being of comparatively modest dimensions wr 102 is notably quite a dense star with its radius measuring just 58 percent that of the sun its mass on the other hand is estimated at 15 to 18 solar masses on its birth it is thought to have been as heavy as 40 to 60 solar masses still the high temperature and robust chemical reactions in the star's interior cause an exceptionally powerful stellar wind whose particle's velocity is over 5000 kilometers per second it takes wr 102 just a few months to lose one earth mass worth of material on account of its stellar wind at this rate of particle emission the star is going to lose one sun mass worth of material in the course of 10 000 years [Music] there are no planets orbiting wr but it is shrouded in a gas envelope not dense and exposed to powerful ultraviolet radiation and strong stellar wind the envelope gets contracted and ionized which sustains its elaborate structure of protuberances and arches all around the star according to a proposed theory the gas cloud around wr102 may probably be remnants of the former hydrogen outer layer of the star another theory maintains that the cloud came to be as a result of the particle flow emitted by the star wr102 is not the only outstandingly blistering place in the universe for example wr-140 wr30a and wr93b as well as the central star in the bug nebula ngc 6302 are as hot as around 200 000 kelvin some white dwarfs may have almost the same surface temperature however all these are no match to neutron stars when neutron stars are born their temperatures may reach a staggering 100 billion kelvin active neutrino emissions cool them off comparatively rapidly but either way the surface temperature of any neutron star is never less than a few hundred thousand kelvin as for their cause they must admittedly be hotter still having said that it is highly improbable that the ultimate temperature record is ever going to be beaten according to today's cosmological concepts the temperature of the universe at the moment of the hypothetical big bang was approximately 1.4 times 10 to the power of 32 kelvin a fundamental physical constant this value is referred to as the planck temperature contemporary physics is not capable of defining a substance of a higher temperature as physical laws are distorted beyond any recognition in such incredibly harsh conditions quite beyond our imagination getting back to wr 102 judging by the data we have on stellar evolution today this star is in its autumn years now as opposed to main sequence stars will reyad's stars do not expand in their final stages of life their substantial mass holds all the star's material together in a dense and hot ball however after losing a lot of its mass through stellar wind the object will eventually get destabilized if current estimates are accurate wr102 appears to be ready to go supernova at any point in the next 1500 years bearing in mind that the distance between the star and the earth is 10 000 light years it is highly likely that the event has already taken place a supernova would have been accompanied by an extra powerful gamma-ray flare fortunately our planet is too far away to suffer any pernicious effects of this dangerous emission wr102 is comprised of rather heavy chemical elements and even iron its later evolution will force it to contract to a critical point the great explosion bringing the star's life cycle to a close will unleash processes of robust proton and neutron capture this way still heavier elements form including transuranium ones eventually wr 102 will be replaced by a neutron star a celestial body unbelievably hot and dense the former star's outer layers disrupted by the explosion will form a nebula slowly cooling off it will give off heat to the space around it many billions of years later this material will be able to form a new planetary system this is the way the large-scale evolution of the universe occurs supernova events release amounts of new elements enabling new planets asteroids and comets to get born these astronomical bodies form elaborate systems bound by gravity the elements making them up mutually react to produce infinite diversity of chemical compounds that is why the cognition of the universe is really and truly quite endless the exact number of galaxies in the universe is not known for certain yet it is supposedly well over several hundred billion galaxies may be of all sorts of different shapes as for the main varieties they include elliptical spiral lenticular and irregular galaxies there are sub-categories for these as well the milky way for example is a barred spiral galaxy since any galaxy consists of a great number of stars these objects masses may reach incredible values the mass of the dwarf galaxy segway 2 for example is just 550 000 times that of the sun as for the supergiant elliptical galaxy ic1101 it is 1700 times heavier than the milky way together with its immediate neighbors our galaxy comprises what is known as the local group it includes over 50 galaxies three of which are quite large in comparison to the others these are the milky way the andromeda galaxy and the triangulum galaxy the diameter of the local group measures approximately 10 million light years and its mass is about 3 trillion times that of the sun together with a few other galaxy clusters of more modest dimensions the local group in its turn comprises the local sheet a flat cloud with a diameter measuring approximately 23 million light years it is about 5 million light years thick the local sheet forms part of the virgo supercluster a vast element of the large-scale structure of the universe the local group is conditionally divided into four parts the first one is the subgroup of the milky way comprised of our galaxy and its satellites which may be either dwarf galaxies or star clusters the milky way is the second largest galaxy in the cluster according to today's estimates it contains 200 to 400 billion stars as well as from 25 to 100 billion brown dwarfs our galaxy has a spiral structure and appears to be a disc with a diameter measuring about 200 000 light years at the same time its thickness is just around a thousand light years still there is a bulge at the center of the disc with a diameter of around 27 000 light years a supermassive black hole with a mass of as much as 4.3 million times that of the sun is supposedly concealed inside the bulge a smaller black hole is said to be orbiting it whose mass is anything from one to ten thousand times that of the sun it is positive that it is dark matter that accounts for most of the mass of the milky way which is why it is impossible to estimate it at this point according to the latest estimates however the mass of our galaxy is approximately 1.5 trillion times that of the sun going slightly further from the milky way we can observe its 31 satellites these are mostly irregular shaped dwarf galaxies they get so twisted and bent in every which way on account of the gravitational influence of their massive neighbor our closest satellite is the dwarf galaxy cma dwarf which can be found in the canis major constellation it lies 25 000 light years away from the earth and 42 000 light years from the center of our galaxy appearing like an elongated ellipsis this dwarf galaxy contains supposedly around 1 billion stars most of which are red giants due to the gravitational influence exerted by the milky way the canis major galaxy has almost broken apart tidal forces had the following disrupting effect the stars torn out from the galaxy came to form the so-called monocerous ring an elaborate ring-shaped structure that traps around the milky way unfortunately observation of cma dwarf is greatly thwarted by gas and dust clouds floating between the galaxy and our earth the largest satellite of the milky way and the fourth largest galaxy in the local group is the large magellanic cloud it is located as far as about 163 000 light years containing approximately 30 billion stars it has a diameter of just seven times as little as that of our galaxy at the same time the cloud's mass is 300 times as little as that of the milky way the explanation for such a stark contrast is this the large magellanic cloud does not happen to contain a supermassive black hole in the center besides there are great amounts of dark matter in the milky way's galactic halo the large magellanic cloud is an sbm type which is in between dwarf spiral and irregular galaxies even though the gravitational influence exerted over it by its massive neighbors has as well as erased almost all traces of its former spiral structure the bar in the center remains to be clearly distinguishable there are a few especially notable objects located in the large magellanic cloud for example the star r136a1 lying 165 000 light years away is the heaviest star ever detected this blue supergiant's mass is 315 times that of the sun and its surface temperature is as scorching as over 40 000 kelvin the luminosity of r136a1 is 8.7 million times that of the sun the large magellanic cloud is also home to one of the largest stars in the investigated parts of the universe the diameter of the red giant woh g64 is over one and a half thousand that of the sun this is just 25 percent less than the diameter of the largest supergiant ever detected stevenson 2-18 according to today's accepted concept of stellar evolution wohg 64 is currently in the final stage of its life and is expected to go supernova at any moment in the next several thousand years when speaking about the milky way subgrip of course we can't but mention the virgo stellar stream occupying approximately five percent of the entire sky it appears as an exceptionally scattered and dim flow of several hundred thousand stars on the outskirts of our galaxy according to the overwhelming majority of scientists the virgo stellar stream is remnants of a dwarf spherical galaxy that has at some point almost completely been swallowed up by the milky way moving yet further we will soon encounter the galaxy known as andromeda or the andromeda nebula together with its satellites it forms part of the local group referred to as the andromeda subgrip the galaxy lies as far as around 800 kilopasc or two and a half million light years we transit the status of our closest neighboring galaxy which isn't a dwarf one diameter of the andromeda nebula measures approximately 220 000 light years which is slightly more than that of the milky way with its star count of around a trillion there are three to five times as many of them in it as there are in our galaxy interestingly the masses of the two galaxies are more or less the same at around one and a half trillion solar masses the point is that the stars forming the andromeda nebula are an average elder and lighter than those of the milky way andromeda is one of our closest neighbours appearing as an elongated light spot it is also one of the few galaxies visible to the naked eye interestingly its angular diameter is six times that of the moon the andromeda nebula is a spiral galaxy with two clearly defined arms it is peculiar for its binary core when we observe it through a telescope we notice two clearly seen star clusters in the center of the galaxy with a distance between them around five light-years according to one of proposed theories at some point andromeda swallowed up another galaxy capturing its core another supposition has it that there is after all just one core with some part of it obscured by a dust cloud it is estimated that the overall mass of the central part of this galaxy is over 140 million solar masses there are approximately 400 globular clusters in the andromeda nebula which is about two to three times as many as the rye in the milky way this means that it probably swallowed up quite a few dwarf galaxies in the past and the clusters it contains now are the remnants of their cores andromeda has around 30 satellites the ones that stand out are dwarf spiral galaxies designations m32 and m110 some theories suggest that m32 round the andromeda nebula several billion years ago leaving a gargantuan hole in its structure this had a serious effect on m32 as well with a substantial part of this galaxy becoming andromeda's galactic halo the milky way is estimated to collide with andromeda in around 5 billion years time today it is still quite impossible to model this tremendous encounter and its consequences accurately but it is bound to be a truly spectacular sight the third large representative of the local group is the triangulum galaxy it is twice as little as the milky way in size and has no confirmed satellites but some dwarf galaxies of the local group may well be gravitationally bound to it the triangulum galaxy is not likely to boast a supermassive black hole in its center the diameter of the galaxy measures approximately 50 000 light years the distance between triangulum and the milky way is 2.7 to 3 million light years the galaxy also contains the ngc 604 nebula which is the largest known area in space where stars are actively born the stellar nursery's diameter reaches 1 300 light years around 200 supergiants with a total mass of a hundred thousand solar masses are compactly grouped here these stars are young and hot with their powerful luminosity ionizing the gas the star cluster is enveloped in this gives the gas a bright glow which in its turn makes the nebula appear quite bright apart from the objects mentioned there are other ones in the local group which don't fall into any of the mentioned subgroups as a rule these are remote dwarf galaxies and star clusters not tightly gravitationally bound to any of the three large galaxies the galaxy ic-10 can be singled out here lying approximately 2.2 million light years away from the sun it is the only galaxy of the local group where stars are actively born ic10 is shrouded in a hydrogen outer envelope whose radius is much bigger than that of the galaxy itself the stellar disk of ic10 meanwhile rotates in the direction opposite to that of the outer envelope with their mind-boggling dimensions of hundreds of thousands of light years on end even the largest galaxies remain tiny dots in the large-scale structure of the universe the distances between them are staggeringly enormous and even light takes millions of years to reach the closest of them nevertheless we can still observe and study them there are innumerable riddles lurking in the cosmos and mankind keeps solving them one after another without flagging zest because every new discovery is just another step in our cognition of the universe the places we've just seen are admittedly just a tiny portion of all the staggering diversity of the space objects known to us if we ever managed to explore them all the list will stretch across quite a number of documentaries by taking small steps we will slowly but surely bring the astronomical map of the areas of space comparatively close to us to a whole new level and with every new celestial body added on this map the picture of the universe is growing ever more appealing [Music] you

Channel: Kosmo

Views: 1,894,221

Keywords: galaxies, planets, space, cosmos, milky way, andromeda, jovian satellites, jupiter's satellites, solar system, galaxy, what lies beyond our galaxy, universe, europa, ganymede, hottest star in the universe, sedna, makemake, comets, the most horrifying planets, satellite galaxies, real scale of the universe, universe to scale, how large is our galaxy, astronomy, film, video, discovery, compilation, cosmo, kosmo

Id: MFSawk8oLTU

Length: 67min 42sec (4062 seconds)

Published: Sun Jun 27 2021