Final answer:
Mars is considered that it could have harbored life due to the presence of water, organic molecules, and methane gas, which are critical components and potential indicators of biological activity.
Step-by-step explanation:
Scientists believe that Mars is a good place to search for life due to several intriguing features.
Firstly, presence of water has been regarded as the most essential aspect for the survival of life, as seen on Earth. Analyses of martian samples indicate that there was once flowing water on Mars, and perhaps oceans, suggesting that the conditions may have been suitable for life.
Secondly, the discovery of organic molecules in these samples suggests that Mars may have had the necessary components for life. These organic, or carbon-based, compounds are fundamental to life as we know it.
Lastly, the presence of methane gas on Mars intrigues scientists because on Earth, biological processes often produce methane, raising the possibility that similar processes could have existed on Mars.