Recent research indicates that objects in the Kuiper Belt, such as Arrokoth, preserve ancient ices from their formation, challenging existing theories and suggesting a “dormant ice bomb” model for cometary behavior. This image was taken by NASA’s New Horizons spacecraft on Jan. 1, 2019 during a flyby of Kuiper Belt object 2014 MU69.
Using a new model they developed to study how comets evolve, the researchers suggest this feat of perseverance isn’t unique to Arrokoth but that many objects from the Kuiper Belt — which lies at the outermost regions of the solar system and dates back to the early formation of the solar system around 4.6 billion years ago — may also contain the ancient ices they formed with.
The work suggests that Kuiper Belt objects can act as dormant “ice bombs,” preserving volatile gases within their interiors for billions of years until orbital shifts bring them closer to the sun and the heat makes them unstable. This new idea could help explain why these icy objects from the Kuiper Belt erupt so violently when they first get closer to the sun. All of a sudden, the cold gas inside them rapidly gets pressurized and these objects evolve into comets.