Pancake-like comets may be made by whirling clouds of pebbles

Spinning clouds of pebbles may lead to the formation of oddly flattened objects in the solar system, including comets and asteroids.

In 2019, NASA’s New Horizons spacecraft flew past an icy, comet-like object beyond Pluto called Arrokoth. It was notable because it seemed to be relatively flat, with each of its two joined lobes squished into a pancake shape. Several other objects in the solar system seem similarly squashed, including comet 67P/Churyumov-Gerasimenko,…