National Aeronautics and Space Administration astronomers said the Wednesday gamma ray explosion shattered the record for the most distant object that could be seen with the naked eye from Earth.

NASA said most gamma ray bursts occur when massive stars run out of nuclear fuel and their cores collapse to form black holes or neutron stars, releasing an intense burst of high-energy gamma rays and ejecting particle jets that travel through space at nearly the speed of light.

"This burst was a whopper," said Swift principal investigator Neil Gehrels of NASA's Goddard Space Flight Center in Greenbelt, Md. "It blows away every gamma ray burst we've seen so far."

Scientists said the event was recorded Wednesday in the constellation Bootes at a distance of 7.5 billion light-years, meaning the event occurred when the universe was less than half its current age and Earth had yet to form.

NASA said the burst was 2.5 million times more luminous than the most luminous supernova ever recorded, making it the most intrinsically bright object ever observed by humans.