1.   This year, the device will be improved so that it will scan the sky once a month and detect asteroids as small as a football field.

2.   Willis and Affleck played offshore oil drillers whose expertise is needed when NASA detects a Texas-sized asteroid on a collision course with Earth.

3.   When such asteroids are detected, they are usually spotted when they are approaching or departing Earth.

4.   When such asteroids are detected, they are usually spotted well out in space when they are approaching or departing Earth.