Simplify the following text for a Grade 8 native English-speaking person.
Original: Gamma-ray bursts are thought to be highly focused explosions , with most of the explosion energy in a narrow relativistic jet traveling at speeds over 99.995 % of the speed of light .
Simplified: However , gamma-ray bursts are thought to be highly focused explosions , with most of the explosion energy collimated into a narrow jet traveling at speeds exceeding 99.995 % of the speed of light .