‘Dirty snowball’ model dashed by images of diverse terrain
ESA/Rosetta/NAVCAM (CC BY-SA IGO 3.0)
It’s time to stop thinking of comets as dirty snowballs. The Rosetta spacecraft’s first look at comet 67P/Churyumov–Gerasimenko shows a diverse, complex world, shaped by eruptions and erosion, that may hint at what the solar system was like 4.6 billion years ago.
A panoply of textures and structures shows that comet 67P is not a loose collection of ice and dust, the prevailing image of comets for decades.
“Rosetta has blown the dirty snowball idea out of the water,” says Nicolas Thomas, a planetary scientist at the University of Bern in Switzerland and member of the Rosetta team.
Previous missions had already hinted that comets were more complex than that. But the Rosetta mission, the first to orbit a comet and follow it as it approaches the sun, shows a patchwork of terrains weathered by blowing dust and gas eruptions.
The data, presented in seven papers in the Jan.