An aim with an orbit that have it almost a light - year from the Sun is about to compensate us a sojourn . We have almost a tenner ’s warning because it is unusually large for a visitant from such a distance ; it could become the largest comet ever come across . Although idea of the object 2014 UN271 ’s flight are changing rapidly as we find more observations in the records , the current best guess is it last come within the orbits of the planets3 million years ago , and it will be even farseeing before it come back .
In galactic terms “ eccentricity ” is a measure of how elongated an orbit is . A perfectly round orbit has an eccentricity of zero , whereas one that is almost boundlessly foresightful than it is wide has a value near one . On this foundation , 2014 UN271 is indeed very gonzo ( with anestimate of 0.99948made by one of its discoverers ) , but it also fits the bill in more colloquial damage , since it ’s not like any aim we ’ve look before .
2014 UN271 is at least 100 kilometers ( 60 miles ) wide , and could be as much as 370 kilometers ( 230 miles ) across . If it ’s a comet , as most object are that have orbits like this are , it ’s a candidate for the enceinte we have ever seen . The closest competitor is thought to be theComet of 1729(Comet Sarbat ) , which was probably around 100 kilometre ( 60 miles ) astray . On the other hired man , if it never ends up give rise a tail there ’s the question of how something with that composition ended up reaching distances a thousand times further from the Sun than Neptune .
The good news is , we have plenty of time to canvass it . Our first effigy of 2014 UN271 were made when it was approximately as far from the Sun as Neptune , but since then it has cut that distance by a tail . In 2031 it will almost touch the orbit of Saturn , before start its outward-bound journeying again . That ’s not close enough for a really good view , barring a sudden scrambling of NASA priorities to mail a foreign mission tointercept it . However , given 2014 UN271 ’s size of it , the JWST may give us quite a view , if it’sfinallybeen launch by then .
approximation of the orbit variegate but look more or less like this
The most exciting part will be if 2014 UN271 really is a elephantine comet and its outer layers set off to vaporize as it stir up up . Whether approaching the orbit of Saturn will be enough to set off this remains to be watch – for many molecules this is still much too far from the Sun to cause them tosublime , but carbon dioxide and carbon monoxide can be released at these distances .
Either path , this will still be the best look astronomer have had at anOort Cloudobject , much small comets aside , and in all likelihood the best view we will get for some time . At best , it may be visible in large backyard telescopes .
Although the first images we have of 2104 UN271 were occupy as part of theDark Energy Surveyin 2014 , it was not noticed at the time . It is only late that astronomersPedro BernardinelliandProfessor Gary Bernsteinof University of Pennsylvania picked up its movement as part of a cryptical dive into the Survey ’s records and traced back to find the oldest figure that captured it . Update : Cometary activityhas been sustain .
[ H / T : Newatlas ]
