The European Southern Observatory (ESO) astronomy institution announced the discovery of a most primitive interstellar comet ever observed in the Solar System. The space body, called 2I / Borisov, is considered an intact relic of its galaxy of origin, still unknown, as it is believed that it probably never passed close to a star and, thus, did not suffer changes by solar wind and radiation.
In this case, it was detected by the largest set of telescopes in the world, called the Very Large Telescope, belonging to the Paranal Observatory – located in Chile. “2I / Borisov may represent the first truly untouched comet ever observed,” said Stefano Bagnulo, leader of the research published in the scientific journal Nature Communications.
To reveal their characteristics in detail, the team used the polarimetry technique – applied in the study of objects based on reflected light. Thus, the method showed that the comet has properties distinct from others already seen in our system and carries immaculate signatures from the cloud of gas and dust from which it was formed.
“It is very plausible [the idea] that it formed under conditions very similar to the origin of the Solar System [4.5 billion years ago],” said Olivier Hainaut, an astronomer at ESO. “The arrival of 2I / Borisov from interstellar space represented the first opportunity to study the composition of a comet from another planetary system and see if its material is in any way different from our native variety”, pointed out Ludmilla Kolokolova, research scientist involved .
Bagnulo explained that a better understanding of these types of primitive bodies is in the exploration plans of the European Space Agency (ESA). “ESA intends to launch the Comet Interceptor mission in 2029, which will have the capacity to hit another visiting interstellar object, during its trajectory”.
In addition, other analyzes are already underway with data from the Atacama Large Millimeter Array (ALMA) radio telescope. In this case, the instrument aims to study grains of dust from 2I / Borisov to gather clues about its origin and the conditions of its home system. This analysis has already indicated that it has small pebbles, about a millimeter in size, on its surface.
Scholars have also found that the relative amounts of carbon monoxide and water in the comet have changed dramatically as it approaches the Sun. Such characteristics suggest that it may be composed of materials that formed in different places in its planetary system.