The most extreme astrophysical phenomena are found in the vicinty of neutron stars and black holes. These exotic objects possess crushing gravitational forces. In their vicinity some of the non-intuitive predictions of Einstein's relativity - like the twisting of space known as frame dragging - can be verified.
The extreme astrophysics group at Steward Observatory is dedicated to probing these intense gravitational fields, through X-ray observations of neutron stars undergoing bursts, and observing the rim of a black hole using the entire earth as a telescope.