In astronomy, the Nemesis Hypothesis postulates that our sun may have a yet undetected companion star called "Nemesis". When the Nemesis star's orbit brings it closer to our solar system, its gravity disturbs the Oort cloud, a mass of comets one light-year from the sun. As a result of these disturbances, a high number of comets are driven through the inner solar system, with a resulting increase in impact events on earth. K-T, the massive dinosaur extinction of the Cretaceous-Tertiary period, is an example of such an event. My work for chamber orchestra is divided into three sections: the "Nemesis" music is grounded and solid; the "Oort cloud" music is more vaporous and mysterious; and the "K-T" impact music is rhythmic and forceful. Musical motives, drawn from a nine-tone source scale, help to link the three sections, creating a musical analogue for this intriguing cosmic phenomenon.