Can you help with finding the mass for me please

m A \"\"1 s"'\"\"' 21 Gravitational fields AQA Physics Exam-style questions 3 The graph in Figure 3 shows how the gravitational potential energy. E\" of a 1.0 kg mass varies with distance. r, from the centre of Mars. The graph is plotted for positions above the surface of Mars. Figure 3 a Explain why,r the values of E; are negative. Gravitational potential at infinity is [1.]. so energy is needed to move an object to iniiin'q,r and energyr will fall as the object moves away,I from infinity,I into a gravitational well. ....................................................................................................................................................................................................................... _ [2 marks} h Use data from the graph to determine the mass of Mars