This is a typical amateur-astronomer’s green laser pointer, shown with a simulated beam. It emits an intense, narrow beam of light that is visible for hundreds or even thousands of meters at night, depending on sky conditions. A recent addition to the backyard astronomer’s toolkit has been flagged as a potential weapon in the terrorist’s arsenal. Humble laser pointers, used by thousands of skygazers to show beginners the way to stars and constellations, is coming under fire from U.S. federal and state authorities following thousands of incidents in which laser beams have “painted” aircraft in flight. In the most notorious case, on January 4, 2005, New Jersey stargazer David Banach was charged with interfering with the operation of a passenger aircraft and lying to federal investigators. He’d been arrested the preceding week after allegedly shining a green laser at a private jet on approach to a nearby airport and then at a police helicopter dispatched to search for the culprit. According to the criminal complaint, after first blaming his 7-year-old daughter, the suspect admitted that he had been giving her a guided tour of the night sky. He fa...