51.   Infrared astronomy allows scientists to peer through dust clouds in space and to break infrared light into constituent colors, revealing various properties of celestial objects.

52.   Million-dollar Tomahawk cruise missiles launched from Navy ships and submarines are aimed at turning terrorist camps into dust clouds.

53.   So she wonders about having her heroine caught in the dust cloud near the World Trade Center in her next novel.

54.   Tests show asbestos, glass particles and caustic powder settled in scores of buildings when the twin towers collapsed and sent dust clouds rolling through lower Manhattan.

55.   The city is under a constant dust cloud as construction crews widen roads, and scaffolding covers many new homes along the roadside.

56.   The collisions create dense dust clouds that trigger star formations, but the clouds are so opaque that the Hubble is blind to them.

57.   The collisions create dense dust clouds that trigger star formations, but the clouds are so opaque that the Hubble Space Telescope is blind to them.

58.   The dust cloud virtually sandblasted the windscreen, forcing the pilot to partially stand up and look out a side window to land.

59.   The worst cases have shown up in people caught in the dust cloud that spread from the collapse.

60.   They slam into the moons, creating explosive dust clouds that eventually turned into orbiting rings so tenuous that the stars shine right through them.