You guide your spacecraft into an orbit a few AU from a black hole.You know it is 4 or 5 solar masses,but you want to measure it more precisely.How would you do so?

Question

Quizplus · Accepted Answer

By measuring the period of the orbit and the semimajor axis, one can use Newton's form of Kepler's third law to estimate the mass of the black hole. This method may give a rough estimate, but it is still a valid approach. Option A is not entirely accurate since there have been indirect methods that have been used to determine the mass of a black hole, such as observing the orbits of stars around the black hole. Option C is not entirely incorrect, but it is not necessary to use a relativistic form of Kepler's third law in this scenario. Option D is not feasible since crossing the event horizon is an irreversible step that would result in destruction of spacecraft, let alone lives.

You Guide Your Spacecraft into an Orbit a Few AU