Borisov

The authors conclude that Borisov is perhaps one of the most pristine objects ever detected.

So the authors think similar conditions may have given rise to both Borisov and Hale-Bopp, in two different star systems.

The similarities between Borisov and Hale-Bopp, along with evidence that both comets’ star systems experienced gravitational stirring, suggests that the evolution of our solar system is perhaps not as unique as we might have thought.

The new data, collected by the Very Large Telescope based in Chile, tells us that the light reflected from Borisov and filtered through its coma is more polarized than the light from any other object that we’ve studied in the solar system.

According to these observations, Borisov’s coma consists of compact, millimeter-size grains—pebbles that are unusually large for a comet.