Astronomers have observed horn-like features forming on the cryovolcanic comet 12P/Pons-Brooks as it makes its closest approach to Earth in 2024. These unusual structures were noted by space weather communications and shared with the scientific community.
Comet Pons-Brooks centers on a solid nucleus roughly 30 kilometers across, made up of cryomagma, a blend of ice, dust, and trapped gases. Surrounding this core is a bright cloud of gas known as the coma. When sunlight heats the interior, pressure builds until a sudden outburst releases material through cracks in the shell of the nucleus. This process drives the visible activity that observers see from Earth and contributes to the comet’s evolving brightness over time.
According to the British Astronomical Association, Comet Pons-Brooks underwent a powerful flare in early October, after which the object appeared tens of times brighter as sunlight reflected off the expanding coma. This brightening is tied to the rapid expansion and dispersal of gas and dust into space, a hallmark of active comets as they respond to solar heating during their solar approach.
Experts suggest the comet’s irregular, horned appearance results from the uneven shape of its nucleus. As 12P moves closer to the Sun, scientists anticipate additional energetic outbursts as pockets of volatile material beneath the surface react to solar energy. These eruptions can reshape the visible features of the coma and tail, offering researchers a dynamic natural laboratory for studying cryovolcanism and cometary geology.
12P/Pons-Brooks is predicted to reach its nearest point to Earth and become visible to the naked eye on April 21, 2024, before receding back toward the outer Solar System. The next close approach to Earth is not expected until 2095, making this a relatively rare observational window for sky watchers and researchers alike.
Historically, observers in the global astronomy community have documented the behavior of comets near perihelion, contributing to a long record of how these icy bodies evolve as they journey through the inner solar system. In recent years, advances in sky surveys and imaging technology have enhanced the ability to monitor fine structural changes on a comet such as Pons-Brooks, shedding light on the interaction between the nucleus and its surrounding environment. This ongoing monitoring helps scientists interpret how cryovolcanic activity progresses and how it influences the appearance of the coma and tail during approach to the Sun.
In related notes, a photographer from Novosibirsk captured footage of a comet flyby, illustrating how amateur observations complement professional data. Such videos provide valuable context for understanding the timing and scale of observed outbursts, especially when coordinated with formal astronomical surveys and observatories.