Gamma-ray bursts(GRBs) are flashes of gamma rays associated with extremely energetic explosions
why nasa interested to Gamma ray burst?
NASA is an agency involved in, among other things, astronomical research, and GRBs are a hot topic in astronomy/astrophysics. On its own website the agency states that according to one of its three main mission directives NASA "explores the Earth, solar system and universe beyond; charts the best route of discovery; and reaps the benefits of Earth and space exploration for society."
When it comes to these ultra-violent cosmic phenomena, our science is still in the "spherical cow" stage. We have theories in astrophysics but can only apply them crudely, not accounting for obvious details.
GRBs are not well enough understood in theoretical terms. In the past we have made some good guesses, such as neutron star collisions, black hole collisions, or something going on with galactic central black holes. Maybe they're due to supernova forming black holes? Maybe something more exotic? We're making progress, but have far to go. GRB research, among other efforts, has helped strike out some ideas in astrophysics and illuminated understanding of others.
By understanding the cause of GRBs, we will understand more about black holes, how they are formed. The details of the "afterglow" can tell us about the material surrounding the black hole. The shape of the gamma ray pulse can tell us a lot, and the timing of the pulse with respect to optical, X-ray and radio emissions can tell us a lot more. If only astrophysicists could swing all their instruments in the right direction quickly when GRBs happen...
At the extreme energy levels involved, there is probably yet-unknown physics going on out there. Quark-antiquark pairs beyond the six flavors we know of, fourth generation leptons, supersymmetry. Unlikely we'll learn anything directly about new particles or forces, but maybe GRB science can help differentiate between proposed extensions of the Standard Model, in very high energy ranges CERN and the upcoming (we hope) International Linear Collider won't be able to reach.
Statistics of GRBs is of interest too. It is believed that the gamma radiation is emitted in narrow beams. How narrow? The narrower, the less likely we'd see it on Earth. Whatever causes GRBs, we'd like to know how often it happens. That could tell us about the formation and evolution of galaxies.