An international team of astronomers using the Hubble Space Telescope has discovered a ghostly ring of dark matter that was formed long ago during a titanic collision between two massive galaxy clusters. It is the first time that a dark matter distribution has been found that differs substantially from the distribution of ordinary matter.
Team member Rick White explains what Hubble revealed and how it will influence future studies of dark matter.
After you listen, e-mail us here and let us know what you think.
Let us know what you think about our podcast by taking this short survey.
To subscribe to our podcast, click here.