Excerpt:
Ahmed Mohamed wants to design the first generators used during a manned mission to Mars. But first he had to take care of some business at the White House.
Attending Astronomy Night on the South Lawn was the latest high point for 14-year-old Ahmed, who was arrested last month for bringing a clock to Irving ISD's MacArthur High School. Irving police called the clock "a hoax bomb."
No charges were filed, but the incident set off an international frenzy, and President Barack Obama invited Ahmed to bring his "cool clock" to the White House soon after.