The missiles are said to be accurate to within a few dozen feet.
The final speed reading, White said, was accurate to within 1 mile an hour.
The teams believe that the current estimates are accurate to within 10 percent.
They are accurate to within one second in 30,000 years.
People in their early 20's were accurate within three seconds, and some got it exactly right.
A new type of atomic clock has the potential to do far better, to be accurate to within a second every few billion years.
In trials they were accurate to within a fifth of a second per day.
They say he's usually accurate within ten miles or so.
The instrument was accurate to within a second of arc.
"And it will be even less accurate within the next few days."
