Huge comets called Centaurus merit bang-up identification as likely undoer of biography on Earth , according to a squad of astronomer from the Armagh Observatory and the University of Buckingham . measure 50 to 100 kilometers ( 30 to 60 international nautical mile ) across , these enormous masses of ice and rock have been place in their hundreds over late X in the trans - Neptunian region – the surface area beyond Neptune , which is the outermost planet in the Solar System .
However , these centaur can make their way of life towards the inner planets as their orbits become debar by the gravitational fields of Neptune , Uranus , and Saturn . bring out a review of their research inAstronomy and Geophysics , the team estimates that centaurs are likely to cross the Earth ’s orbit every 40,000 to 100,000 geezerhood .
Depending on the sizing , composition , and aloofness of a given comet , its effect on terrestrial ecosystem are likely to be highly variable . Because centaurs are thought to be precarious , the source have a bun in the oven the majority of these effects to be induce by dust and other small-scale fragments that ensue from the disintegration of the comet .
They figure that a single Centaurus measuring 100 kilometers ( 60 miles ) could contain about 100 times the mess of all the Earth - spoil asteroids detected to escort . This translates to an horrific mickle of rubble , leading the researcher to intimate that comets of this size could fill the Earth ’s atmosphere with tiny particles , reduce the amount of sunshine that can pass through to roughly the level of Moon , for up to 100,000 twelvemonth . This , they say , would put an end to commercial-grade agriculture .
A mapping of the Solar System , showing the orbits of several planets . In red are the ambit of 22 centaurs . In sensationalistic are the cranial orbit of 17 trans - Neptunian objects . Duncan Steel / Royal Astronomical Society
Additionally , larger fragments – which could extend for several kilometers in length – may render ruinous encroachment , similar to that which is believed to have lead to theextinction of the dinosaur . harmonize to the report , several such collisions may have pass in the past , with the writer citing craters in the Gulf of Mexico , Ukraine , Siberia and Chesapeake Bay as likely nominee for Centaurus impact sites .
devote the probability of a centaur cross Earth ’s orbit at some point in the future , and the filmy bulk of dust induce by the disintegration of these comets , the team arrogate that some level of impact is inevitable , although the nature and extent of the upshot are likely to count on various factors .
At present , attempts to quantify Earth ’s risk of exposure of being affect by a collision are centre around NASA’sSpaceguardinitiative , which seeks to map up to 90 percent of near - Earth objects ( NEOs ) larger than 1 kilometer ( 0.6 miles ) . This program focuses chiefly on the asteroid belted ammunition that sits between Mars and Jupiter , although Professor Bill Napier , who helped to transmit this research , is now calling for the oscilloscope of this hunting to be extended to the out reaches of the Solar System .
“ Our work evoke we need to look beyond our immediate neighborhood and calculate out beyond the orbit of Jupiter to determine Centaurus , ” he allege in astatement . “ If we are correct , then these distant comets could be a serious fortune , and it ’s meter to read them well . ”
