Boffins: Antimatter comes from black holes, neutron stars

[Rick]

Topflight astrophysics boffins believe they may have cracked the tricky problem of how to make antimatter, which would be useful for many purposes: for instance powering relatively practical starships, or - of course - blowing up an entire planet in one go. However, it appears that making antimatter requires the possession of a black hole or a neutron star, so it won't be happening any time soon.

More: http://www.theregister.co.uk/2008/01/15/antimatter_black_hole_collapsar_neutron_star_unexpected/