Comet 67P changed color like a cosmic chameleon as it cruised around our Solar System . Thanks to a fresh look at the data produced by the Rosetta space investigation , a squad of European scientists has detailed how the comet ’s nucleus appeared to change from red to low-spirited as it come into faithful eye socket with the Sun before grow reddish again as it voyaged into deep space .
According to their analysis , report in the journalNature , this was all down to how much H2O glass or dust was lay out on and around the comet . The gloss come out redder when there are more organic molecules rich in carbon , but seem bluer if there are higher levels of frozen body of water ice that ’s plenteous in magnesium silicate .
Comet 67P / Churyumov - Gerasimenko was closely observe for around two years by the European Space Agency ’s ( ESA ) Rosetta probe , which make do toreach and protrude orbiting the cometin August 2014 . During the deputation ’s early days , the comet ’s lens nucleus was relatively far away from the Sun and cut across in layer of detritus and a short minute of ice . This made the comet seem ruby surrounded with an icy blue daze ( thecoma)when psychoanalyse with the Visible and Infrared Thermal Imaging Spectrometer ( VIRTIS ) instrument .
As it come near the Sun , the comet crossed a boundary called the frostline , heating the ice and turning it into gas , a process call sublimation . However , sublimation of the urine ice rink also pushed out the surface dust granulate too , revealing layer of fresh pristine crank . This made the nucleus turn bluer in color when consider by VIRTIS .
After the comet looped around the Sun and begin its journeying back into deep space , its previous show resumed with the core becoming redder and the comatoseness bluer .
“ Spectral analysis indicates an enrichment of submicrometre metric grain made of constitutional material and shapeless atomic number 6 in the coma , have reddening during the passage . At the same time , the progressive remotion of junk from the nucleus causes the exposure of more pristine and blueish icy layer on the control surface , ” the report generator summarise in their paper .
There are still many gaps in our knowledge of comet , despite the valiant work of Rosetta and its lander module Philae . For example , we still do n’t understand much about the dusty constitutive molecules rich in C that appear cherry-red .
Until researcher can get their hands on these molecules from a piece of the comet , the well wager for understanding these organics is using data gathered by VIRTIS .
" There are unquestionably more exciting result to hail , " Matt Taylor , ESA labor scientist for Rosetta , suppose in astatement . " The data ingathering may be over , but the analysis and the results will keep for years yet , adding to the fertile legacy of cometary knowledge provided by Rosetta . "
