A new way of studying the gravity of Mars has confirmed the theory that the red planet once had a vast ocean in its northern hemisphere.
The method, which uses gravity aspects derived from gravity anomalies, gives a clearer picture of the ancient Martian water body than previous approaches.
The late Noachian period:
Mars was not always a cold and dry planet. Scientists believe that about 4 billion years ago, Mars had a warmer and wetter climate, with rain falling near the equator and carving out valleys with flowing water. The late Noachian period is considered the most habitable time on Mars when life could have emerged. However, this favorable climate did not last long, and Mars gradually lost its atmosphere and water, becoming the barren world we see today. The new study suggests that the habitable period on Mars lasted longer than previously thought, by about 500 million years, until the late Hesperian age. This means there was more time for life to evolve on Mars if it existed.
