Comet 67P-G gets its strange, distinct shape from being two separate objects that smashed into one another and remained stuck together.
According to BBC News, Rosetta mission managers discovered the comet is layered in a way that can only be achieved through a collision. The scientists behind the discovery will published their work in the journal Nature.
"It is clear from the images that both lobes have an outer envelope of material organized in distinct layers, and we think these extend for several hundred meters below the surface," study lead author Matteo Massironi, of the University of Padova, Italy, and an associate scientist of the OSIRIS team, said in a news release. "You can imagine the layering a bit like an onion, except in this case we are considering two separate onions of differing size that have grown independently before fusing together."
The European Space Agency launched the Rosetta spacecraft in 2004 and ten years later it successfully dropped the Philae lander on Comet 67P-G, the first time a spacecraft attached itself to a comet. One of the first aspects of the comet mission managers noticed was that its shape resembled that of a rubber duck.
Now, they know the place where the duck's neck would be is where the two objects joined together.
"Our study rules out the possibility that the comet shape is the outcome of erosion," Massironi told Discovery News. "The heating and partial melting at the impact location and the subsequent cooling and gluing of the two bodies explain the shape of the neck region."
