Produced by: Tarun Mishra Designed by: Manoj Kumar
A new hypothesis suggests that Mars' unusual terrain could be the result of a long-lost large moon, which might have influenced the planet's shape and geology.
Michael Efroimsky, an astronomer at the U.S. Naval Observatory, proposed the idea in a paper submitted to the Journal of Geophysical Research: Planets.
Mars features some of the most striking terrain in the solar system, including the massive Tharsis bulge, the tallest mountain, and the largest canyon. The Tharsis bulge, near the equator, spans about 3,100 miles (5,000 km) and rises up to 4.4 miles (7 km).
The proposed lost moon, named Nerio, could have played a key role in shaping this terrain. Similar to how Earth's moon raises ocean tides, Nerio may have raised tides in Mars' magma oceans, deforming the planet as it cooled.
The moon may have been destroyed in a collision, possibly leaving behind Mars' current moons, Phobos and Deimos, or it may have been ejected from the solar system following a gravitational interaction with another body.
While no direct evidence of Nerio remains, Efroimsky's hypothesis suggests that the moon's gravitational influence was sufficient to deform Mars' shape, contributing to the planet's current extreme terrain.
One challenge to the hypothesis is the lack of craters that would align with Nerio's orbit if it had been destroyed. Further impacts and geological activity on Mars might have erased such traces.
Efroimsky proposes that subsequent geological processes could have enhanced the initial deformations caused by Nerio, uplifting highlands and contributing to Mars' distinctive features.
Efroimsky invites other researchers to investigate the possibility of this lost moon and to explore methods for finding evidence of its influence on Mars' shape and terrain. The hypothesis remains open for further evaluation.