In 2019, the scientific community went into heated debates after our solar system was visited by an interstellar object for the first time in documented history. The elusive nature of Oumuamua was discussed by a large number of people, with some theories leading to significant controversies.
A second object observed by astronomers in December as it traveled through the area closest to the sun (called perihelion). It is estimated that the object, which is a comet classified under the name of Comet 2I/Borisov, will reach Jupiter in the summer and Saturn during the first months of 2021.
The shape of Oumuamua was one of its most exciting aspects and a hot topic. On the other hand, Borisov looks and acts like a comet, sporting an impressive coma and releasing gas as it travels. The coma is a cloudy mixture of gas and dust, which is often generated by comets and offers the classic tear shape with the iconic tail.
More About the Second Interstellar Visitor
Hubble captured impressive images of the object, and a team of researchers analyzed them in a bid to learn more about the object. By taking into account traits among which we can count the level of brightness on the surface, acceleration patterns, and the release of gas, the scientists estimated the size of the nucleus.
The results infer that it has a radius between 200 to 500 meters, considerably smaller in comparison to initial observation, which anticipated a radius of up to 16 kilometers. It was also theorized that Borisov has a minimum density of 25 kilograms per cubic meter, which is considerably smaller in comparison to that of our planet, which has an average of 5,500 kilograms per square meter. This information is essential since it allows researchers to exclude irrelevant models.
The small radius makes Comet Borisov more sensible to torques produced by outgassing, and its spin could be affected by going so close to the sun. More details can be found in a paper published in a scientific journal.