If Jackson's reconnaissance party was riding in bright moonlight, then his own men should have recognized them as they returned from the Union's side, but Olson and Jasinski say they did not -- for good reason.
"The 18th North Carolina was looking to the southeast, directly toward the rising moon," they said. It stood at "25 degrees above the horizon" at the time, just at the wrong angle.
"The bright moon would've silhouetted Jackson and his officers, completely obscuring their identities."
The Confederate infantrymen likely thought their own men returning were Union cavalrymen on the approach.
"Our astronomical analysis partially absolves the 18th North Carolina from blame for the wounding of Jackson," Olson says.
It comes too late for the man who gave the order to fire.
Maj. John D. Barry died at age 27 -- just two years after the end of the war.
"His family believed his death was a result of the depression and guilt he suffered as a consequence of having given the order to fire," the Virginia Military Institute site says.
Stonewall Jackson may have appreciated the Texas State researchers' hypothesis, not only because it would have alleviated the conscience of the men who took his life.
Before joining the Confederate Army, he was a science professor.