Description: 2I/Borisov is the second known interstellar object to pass through our solar system, and the first to be clearly identified as an interstellar comet. Discovered in 2019, it differed from ʻOumuamua (the first detected interstellar object) because it displayed typical cometary features: a visible coma (cloud of gas and dust) and a tail formed as it approached the Sun.
Its passage confirmed that our solar system is not isolated and that objects from other star systems can indeed cross into it. 2I/Borisov offered an unprecedented opportunity to closely study material formed around another star, helping to expand our understanding of planetary formation processes across the galaxy.
History: 2I/Borisov was discovered on August 30, 2019, by Ukrainian amateur astronomer Gennadiy Borisov using a homemade telescope. Upon analyzing its trajectory, astronomers quickly confirmed that its orbit was hyperbolic, indicating an origin outside of the solar system.
Unlike ʻOumuamua, 2I/Borisov was already active when detected, sublimating and forming a visible coma and tail, allowing scientists to study its composition in detail. Its nucleus was found to contain high amounts of carbon monoxide and other substances, in some cases greater than what is typically observed in comets from our solar system.
This unique observational window strengthened the hypothesis that comet formation processes are common across different planetary systems.
Uses:
- Research on planetary system formation: Helps compare the chemistry of interstellar comets with those formed in our own solar system.
- Orbital dynamics modeling: Aids in refining the study of hyperbolic trajectories and interstellar dynamics.
- Preparation for future missions: Provides a foundation for designing missions aimed at intercepting or studying interstellar objects.
Examples:
- Hubble Space Telescope observations (2019-2020): Hubble captured high-resolution images of 2I/Borisov, revealing detailed views of its coma and tail.
- Chemical studies: Scientists discovered carbon monoxide levels significantly higher than those in local comets, suggesting that 2I/Borisov formed in a very cold environment, likely farther from its original star than typical solar system comets.
- Astronomical comparisons: 2I/Borisov is used in studies to better understand chemical variability between different stellar systems.
