The closed book of comets are finally being uncover . We now know that comets organise at the same time as the rest of the Solar System , according to the latest data from comet 67P / Churyumov - Gerasimenko .
Rosetta , the European Space Agency ’s spacecraft , has been analyzing 67P in item and discovered that most ice found in this objective formed from the original protoplanetary nebula from which the Sun and the satellite later emerged . The uncovering settles a decades - old public debate about when comet actually formed .
The structure of the ice molecules tells a flock about the formation of comet . frappe can form in two ways , either as crystal shabu or amorphous ice . The latter forms when H2O particle cool off quickly ; they do n’t have to organize in a nice precise structure . If the chilling is gradual , the water forms in crystals . There is also another important difference that has an astrophysical effect : shapeless ice trap a lot more gas when it cools .
Rosina , one of the instruments on card Rosetta , measured the amount of sealed accelerator ( nitrogen , argon , and carbon dioxide ) in 67P , and detected measure a hundred meter smaller than what ’s require from amorphous ice , indicating a definite crystalline structure .
This is a major breakthrough because it admit us to determine the age of comets . Amorphous frosting forms in interstellar infinite where there are no heat sources . When stars begin to form , the protoplanetary nebula is ardent enough for the interstellar Methedrine to sublimate . As the nebula chill down and the planets begin to form , water freezes into frosting crystals , trapping some gas within .
Comets made of crystalline ice then must have formed at the same fourth dimension as the rest of the Solar System . The enquiry , release inThe Astrophysical Journal , bespeak that 67P must have formed between -228 and -223 ° C ( -378 to -369 ° degree Fahrenheit ) to trap the correct quantities of gas keep .
These findings could have upshot beyond comets . Many formation scenario for the throttle giant planets and their moons , as well as objects in the Kuiper Belt ( like Pluto ) , want the agglomeration of crystalline ice .
