A recent study has revealed that Mars was once warm and wet billions of years ago. This finding is in stark contrast to another prevailing theory that the planet was primarily cold and icy during this period. The implications of this study extend to the possibility that life could have developed on Mars at that time.
The question of Mars' past habitability has been a subject of deep fascination and research for many decades. Like Earth, Mars is approximately 4.5 billion years old, and its geological history is categorized into various epochs.
The latest research focuses on Mars during the Noachian epoch, which lasted from about 4.1 to 3.7 billion years ago. This epoch coincided with a period in the solar system's history known as the Late Heavy Bombardment (LHB), characterized by massive meteorite impacts. Evidence of these cataclysmic events is found across many celestial bodies.
On Mars, the vast Hellas and Argyre impact basins are two significant remnants from this era. Each basin is over a thousand miles wide, with the capacity to hold more water than the entire Mediterranean Sea.
Despite the turbulent conditions, this era may have been the most conducive to life on Mars. Numerous landforms, such as dried-up river valleys, lake beds, ancient coastlines, and river deltas, suggest that water shaped the planet's surface during this time.
The climatic conditions of the Noachian epoch remain hotly debated. Two primary scenarios are considered: one suggests a cold, icy environment with sporadic melting caused by meteorite impacts and volcanic eruptions, while the other proposes a consistently warm, wet, and largely ice-free climate.