抄録
Recent paleomagnetic studies on the Martian meteorite ALH84001 have shown that this rock traveled from Mars to Earth with an internal temperature entirely below 40°C. Dynamical studies indicate that the transfer of rocks from Mars to Earth (and to a limited extent, vice versa) can proceed on a biologically-short time scale, making it likely that organic hitchhikers have traveled between these planets many times during the history of the Solar system. These results demand a re-evaluation of the long-held assumption that terrestrial life. first evolved on Earth, as it could just as easily have evolved on Mars and traveled here. We argue here that the chemical environment on early Mars would have been better for the evolution of early biochemical reactions than that of early Earth.
