Dear student, Although Earth, Mars and Venus are neighbors, yet they have a very contrasting atmosphere from each other. While earth atmosphere is suitable for the existing life forms, venus and mars atmosphere cannot support different life forms. As compared to earth, venus has a very high temperature while mars have a very low temperature. Also, the atmosphere of venus are mars are rich in carbon dioxide while earth has a rich amount of oxygen. Moreover difference in water levels and atmospheric pressure makes the atmosphere of mars and venus different from that of earth. Regards