The ESA is on a roll. After purposefully crashing a spacecraft into the Moon last week, they just published the first-ever census of Black Holes using their orbiting Gamma Ray spacecraft namesd Integral.
One of the cool things about the project is that they ended up using the Earth itself as a giant shutter in order to compose the gamma ray map image. Check out the cool map and links to the ESA site.
"An international team, lead by Eugene Churazov and Rashid Sunyaev, Space Research Institute, Moscow, and involving scientists from all groups of the Integral consortium, used the Earth as a giant shield to watch the number of tell-tale gamma rays from the distant Universe dwindle to zero, as our planet blocked their view."
"Integral spotted about 300 individual sources in our Galaxy and around 100 of the brightest supermassive black holes in other galaxies. These are the tip of the iceberg. Astronomers believe there are tens of millions of active black holes spread throughout space, all contributing to the gamma-ray background."Now, if only we could connect them in a web of wormholes and travel across the universe!