Science behind comets' formation revealed

In a recent study, the Rosetta's target 'Chury' and other comets observed by space missions have shown a common evidence of layered structures and bi-lobed shapes.

Astrophysicist Martin Jutzi with the help of 3D computer simulations was able to reconstruct the formation of these features as a result of gentle collisions and mergers.

In the study, the researchers with their three-dimensional computer models, reconstruct what happened in the early solar system. Comets or their precursors formed in the outer planets region, possibly millions of years before planet formation.

Matin Jutzi said that reconstructing the formation process of comets can provide crucial information about the initial phase of planet formation.

The researchers applied 3D collisional models, constrained by these shape and topographic data to understand the basic accretion mechanism and its implications for internal structure. As their three-dimensional computer simulations indicate, the major structural features observed on cometary nuclei can be explained by the pair-wise low velocity accretion of weak cometesimals.

The model is also compatible with the observed low bulk densities of comets as the collisions result in only minor compaction.

Alternatively, the same processes of coagulation might have occurred among debris clumps ejected from much larger parent bodies. Along with future space missions using radar to directly image internal structure, the 3D computer simulations are an important step to clarify the question of how the cometary nuclei were assembled.

The study has now been published online in the journal Science Express.