Rosetta comet likely formed from 2 separate objects

Since that time, material vaporizing from sunlit areas of the comet and then condensing in shadowed regions (which a recent report suggests are about 50°C cooler than those illuminated by the sun) may have helped form the neck joining the once-separate objects. Indeed, scientists are saying, “Two independent and primitive envelopes of the bilobate nucleus of comet 67P”. Either localised erosion created the ‘neck, ‘ or comet 67p formed after two comets merged.


“This was the first clue that the two lobes are independent, reinforced by the observation that the layers are inclined in opposite directions close to the comet’s neck”, Matteo said.

In the year and change since the European Space Agency’s Rosetta mission became the first spacecraft to orbit a comet, the probe has made all sorts of discoveries about the object known as Comet 67P/Churyumov-Gerasimenko-for instance, that it’s bumpy, not smooth as expected, and is covered in dark, carbon-rich compounds with surprisingly little ice.

The two lobes have similar composition, so the team still believes they were formed from smaller pieces of material in the same region of space. The cosmic fender bender may have happened less than 100 million years after the solar system formed. In this scenario, the comet would have started with a more spherical shape. It puts another mark in the column for the hypothesis that the comet’s odd shape is the result of sculpting from an initially conventional shape.

ESA’s Rosetta probe took ten years to reach its target last July and, when it did, the science team had a bit of a shock.

It had enough onboard power for three days of experiments before going to sleep on November 15.

Rosetta, in the meantime, has continued its comet-probing duties with a palette of 11 science instruments – cameras, radar, microwave, infrared and other sensors to analyse the comet surface and gases escaping from it. This latest detection actually adds to the debate about the role of comets in delivering the “ingredients” of life to Earth and other planets.


“Rosetta will continue to observe the comet for another year, to get the maximum amount of information on this celestial body and its place in the history of our solar system”, he said. “But to better understand how much 67P is representative of the comet-formation process, the exploration of a larger sample of comets is definitively needed”.

2014. The comet started off as two separate bodies that later fused a new study shows. – Reuters pic