New observations of the interstellar comet 3I/ATLAS have provided intriguing insights, suggesting the presence of active “ice volcanoes” on its surface. Researchers believe that as the comet nears the sun, it undergoes a series of cryovolcanic eruptions, characterized by jets of gas and dust. This phenomenon has been classified as cryovolcanism and is detailed in a study recently shared on arXiv.
The findings indicate that 3I/ATLAS shares similarities with icy trans-Neptunian objects, which include dwarf planets that reside beyond Neptune’s orbit. This revelation surprises researchers, as it highlights that a comet originating from another solar system can possess characteristics akin to those found in our own celestial neighborhood. Josep Trigo-Rodríguez, the lead author and a researcher at the Institute of Space Sciences in Spain, expressed enthusiasm over this connection, emphasizing the remarkable mixture of materials found on the comet.
Since its discovery in July, there has been much speculation about the comet’s origins, including theories suggesting it could be an alien spacecraft. However, experts largely agree that 3I/ATLAS is a comet from an unknown star system. As only the third interstellar object ever recorded, it presents a unique opportunity for scientists to examine conditions from beyond our solar system, potentially shedding light on the early history of our universe.
To study 3I/ATLAS, Trigo-Rodríguez and his team observed the comet using the Joan Oró Telescope in northeastern Spain, collaborating with other local observatories. Their observations coincided with the comet’s nearest approach to the sun on October 29, revealing that it intensified its sublimation—a process resulting from heating—when it came within approximately 235 million miles of our star, leading to a rapid brightening. The researchers captured high-resolution images showcasing jets of gas and dust, interpreted as evidence of cryovolcanic activity.
Typically found on icy bodies, cryovolcanoes release vapor and dust formed by internal heat melting the icy surface. For 3I/ATLAS, researchers attribute the suspected cryovolcanism to reactions within the comet’s core, driven by the sun’s heat altering the state of carbon dioxide.
In order to further understand the comet’s composition, the researchers conducted a spectroscopic analysis comparing the comet to carbonaceous chondrites, early solar system meteorites collected in Antarctica. They noted that one of the samples likely originates from a trans-Neptunian object. The study revealed that 3I/ATLAS could be rich in metals and shares traits with primeval remnants from our solar system’s formation.
While the exact size of 3I/ATLAS remains uncertain, estimates from Hubble Space Telescope observations suggest it measures between 1,400 feet and 3.5 miles wide. If the researchers’ speculations about its size and composition hold, 3I/ATLAS could weigh more than 660 million tons.
Despite its similarities to trans-Neptunian objects, comet 3I/ATLAS is confirmed to be of interstellar origin due to its hyperbolic trajectory, which scientists initially observed as it sped through space at approximately 137,000 miles per hour. The comet’s journey has likely spanned billions of years, making it potentially over 3 billion years older than our solar system.
The exact star system from which comet 3I/ATLAS originated is unknown. The comet’s long time in space may have led to significant irradiation, complicating the task of tracing its origin. Trigo-Rodríguez emphasizes the importance of studying interstellar comets not only for their potential collision risks but also for valuable insights they offer about the chemistry and conditions of other regions in our galaxy.
The findings provoke excitement and curiosity in the scientific community, as studying such extraordinary objects holds the promise of deepening our understanding of cosmic evolution and the unique processes shaping celestial bodies across the universe.