The different instruments were needed to track down the target galaxies, measure star formation and identify mergers, and, crucially, with Chandra, see the X-ray emissions that come from heated material as it is sucked into a black hole.

BBC: NEWS | Science/Nature | Deepest X-rays tell merger story

Holt, whose great-grandfather invented the first track-type tractor (which led to the formation of Caterpillar), came to the rescue in 1996.

FORBES: Magazine Article

Holt, whose great-grandfather invented the first track-type tractor (which led to the formation of Caterpillar (nyse: CAT - news - people )), came to the rescue in 1996.

FORBES: It's How You Play the Game