Oort Cloud

[airbolt]

I was listening to " A Brief History of Everything" by Bill Bryson and he said that the existence of the Oort Cloud was only theoretical as it could not be observed. Have any advances been made in proving the existence of The Oort Cloud?

[heathfield]

Apparently not. Scientists are hoping that a large mass might pass through it, disturbing the status quo, and sending some new comets in our direction. But even that wouldn't amount to a proof.
The term 'cloud' is, I feel, a bit unfortunate - it implies a certain density. I rather think that any objects out there will be very, very, far apart from each other.

[jake-the-peg]

Well Sedna was discovered in 2004 well beyond the kuiper belt in what would be the inner Oort Cloud

http://www.journals.uchicago.edu/cgi-bin/resol ve?id=doi:10.1086/422095

It's interesting because it's a lot closer that where the Oort cloud is traditionally though of as being but still shows there are some substanial objects a long way out