NuSTAR is the first focussing hard X-ray satellite in orbit, providing more than two orders of magnitude improvement in sensitivity as compared to previous high-energy missions working at similar energies. The primary science goals of NuSTAR are broad, and include studying a range of high-energy sources.  Also, since the powerful phenomena studied by NuSTAR are often variable and emit through a range of processes, NuSTAR is a key NASA tool for exploring the time-domain and multi-messenger (TDAMM) universe.

Black Holes are tears in the fabric of space time and are among the most exotic objects in the Universe. As they accrete matter, black hole systems generate the high-energy X-ray light studied by NuSTAR. NuSTAR has a range of programs studying black holes, from stellar mass black holes in our own Milky Way Galaxy to supermassive black holes in the hearts of distant galaxies. 

Neutron Stars are incredibly dense remnants left over when some of the massive stars consume all their fuel.  They have masses comparable to the Sun, but sizes comparable to a small city such as Pasadena.  NuSTAR has several programs studying the high-energy emission from neutron stars, which are teaching us about their formation, composition, and physical states.

Relativistic Jets of radiation and particles traveling at close to the speed of light are some of the most powerful sources of high-energy emission in the Universe, from the X-rays to the even more energetic gamma-rays.  NuSTAR studies relativistic jets at distances up to billions of light years that are acting as powerful cosmic accelerators and provide insight into the most extreme physical conditions.

Supernovae Explosions occur at the end of the lives of massive stars and are essential for the cosmic cycle of matter in the Universe.  These powerful explosions generate and distribute the heavy elements needed to create people and planets.  NuSTAR studies both newly detected supernovae as well as the remnants of historical supernovae, thereby improving our understanding of these important energetic events.

The Milky Way Galaxy hosts a range of high-energy emitters, from black holes to neutron stars to diffuse clouds.  NuSTAR has several programs studying Galactic high-energy sources, including the supermassive black hole at the center of our Galaxy.

The Sun also produces high-energy light that can be studied by NuSTAR.  As the first focusing X-ray satellite, NuSTAR has a range of solar programs which will improve our understanding of our nearest star.