The first known interstellar comet to visit our solar system may be the most pristine ever found, never passing near a star until visiting our own, researchers say.

In 2019, scientists discovered the comet 2I/Borisov as it streaked into the solar system. The comet's speed and trajectory revealed it was a rogue comet from interstellar space, making it the first known interstellar comet and the second known interstellar visitor after pancake-shaped 1I/'Oumuamua.

Now scientists have found two new ways in which 2I/Borisov is unlike any known comet. They detailed their findings online March 30 in two studies, one published in the journal Nature Communications and another study in the journal Nature Astronomy.