Interstellar comets visit our solar system more frequently than thought

[Judi Lynn]

By Tereza Pultarova about 5 hours ago

Just because we don't see them doesn't mean they're not here.

Comets from other star systems, such as 2019 Borisov, visit the sun's neighborhood more frequently than scientists had thought, a new study suggests.

The study, based on data gathered as Borisov zipped by Earth at a distance of about 185 million miles (300 million kilometers) in late 2019, suggests that the comet repository in the far outer solar system known as the Oort Cloud might be full of objects that were born around other stars. In fact, the authors of the study suggest that the Oort Cloud might contain more interstellar material than domestic stuff.

Named after famous Dutch astronomer Jan Oort, who first proved its existence in the 1950s, the Oort Cloud is a spherical shell of small objects — asteroids, comets and fragments — far beyond the orbit of Neptune. The cloud's inner edge is thought to begin about 2,000 astronomical units (AU) from the sun, and its outer edge lies about 200,000 AU away. (One AU is the average Earth-sun distance — about 93 million miles, or 150 million kilometers.)

No spacecraft has ever visited the Oort Cloud, and it will take 300 years for NASA's farflung Voyager 1 probe to even glimpse the cloud's closest portion.

Astronomers have very limited tools to study this intriguing world, as objects in the Oort Cloud don't produce their own light. At the same time, these objects are too far away to reflect much of the sun's light.

More:
https://www.space.com/interstellar-comets-more-common-solar-system?utm_source=notification

[PoindexterOglethorpe]

1. Oh, my.

And to think I was talking with My Son The Astronomer a few minutes ago. We were talking about his research and the papers he is working on. He's doing exoplanet research, but he tends to be knowledgeable about various other aspects of astronomy.

I will need to put in another call to him about this.