A group of scientists led by Bagnulo uses a technique called polarization analysis to measure the polarized light produced by 2I/Borisov. When light passes through a filter (such as the lens of sunglasses or comet material), it becomes polarized light. By studying the properties of sunlight polarized by the dust of the comet, researchers can understand the physical and chemical properties of the comet.
This analysis shows that 2I/Borisov is different from almost all other comets studied except Hale-Bopp. Astronomers believe that Comet Hale-Bopp passed the sun only once before returning to the sun in the late 1990s. The earlier return is thought to have occurred thousands of years ago in 2215 BC, when Hale-Bopp may have collided with Jupiter, changing its orbit and passing it over the sun for the first time . Since Hale-Bopp has very little interaction with the sun, it is also considered a primitive comet, and its composition is very similar to the gas and dust clouds in our solar system that formed 4.5 billion years ago.
Polarization data shows that 2I/Borisov is more primitive than Hale-Bopp. 2I / Borisov shows the non-destructive characteristics of gas clouds and formed dust clouds. Evidence also shows that both comets formed under similar conditions, but in different solar systems. Alberto Cellino of the Turin Observatory said:
The fact that these two comets are very similar indicates that the origin environment of 2I/Borisov is not very different in composition from the environment of the early solar system.
The second team of scientists analyzed 2I/Borisov's dust particles using telescope data and published their findings in a peer-reviewed journal on March 30, 2021. Natural astronomy.
They found that the comet's coma-the dust wrap around the main body of the comet-contained dense pebbles. These pebbles are particles about 1 mm (0.04 inch) or larger in size. The research team also noticed that as the comet approached the sun, the relative content of carbon monoxide and water changed dramatically. These scientists believe that these changes indicate:
...Comets are made of materials formed at different locations in their planetary system.
Observations [Bin Yang, an astronomer at ESO in Chile] Her team suggested that the material in the 2I/Borisov planetary house mix from near its star to farther away. This may be due to the existence of giant planets whose strong gravity stirs the material in the system.
Astronomers believe that a similar process occurred in the early stages of life in our solar system.
When amateur astronomer Gennady Borisov discovered Comet 2I/Borisov in August 2019, it became the only second known celestial body to visit our solar system from interstellar space. The first discovered was "Oumuamua, in October 2017." Oumuamua moved at a speed of 58,900 miles (94,800 kilometers) per hour until it swung past the sun and accelerated it to 196,200 miles (315,800 kilometers) per hour.
These flourishing interstellar tourists have now left the solar system and returned to interstellar space.
Bottom line: According to a new study, the second known interstellar object is called Comet 2I/Borisov by astronomers on Earth, and may be one of the most primitive objects ever.
Source: Interstellar Comet 2I / Borisov's abnormal polarization characteristics
Source: Evolution of dense pebbles and volatiles in the interstellar comet 2I/Borisov