The Red Planet presents a geological puzzle: Why does its southern hemisphere rise significantly above the smoother northern plains? A groundbreaking study using seismic data from NASA’s InSight mission reveals the answer, offering fresh insights into planetary evolution and reshaping our understanding of Mars’ history.
By Rachel Hamilton
A Planetary Puzzle
Since the 1970s, scientists have been intrigued by Mars’ striking geological contrast, known as the Martian dichotomy. The southern highlands rise up to six kilometers above the smoother, younger northern plains, making it one of the Solar System’s most unique features. For decades, researchers debated whether the contrast was caused by an asteroid impact or by internal geological forces.
A recent study, published in Geophysical Research Letters, utilized seismic data from NASA’s InSight lander to delve deeper into the mystery. The findings point to internal processes, such as mantle convection, as the primary cause, revealing that the answer lies deep beneath the Martian surface.
Internal vs. External Forces
Two competing theories have long dominated the discussion:
- Endogenic Hypothesis: This theory attributes the dichotomy to internal processes like mantle convection or tectonic activity.
- Exogenic Hypothesis: This suggests external factors, such as a massive asteroid impact, created the contrasting hemispheres.
The latest seismic data strongly supports the endogenic hypothesis. Researchers detected temperature differences beneath the two regions, with rising heat beneath the southern highlands and cooling in the northern plains, aligning with mantle convection models.
Marsquakes Provide Key Evidence
NASA’s InSight lander, equipped with a single seismometer, recorded Marsquakes that offered critical clues. The southern highlands, particularly the Terra Cimmeria region, displayed signs of hotter, thicker crust. These findings suggest Mars once had active tectonic plates, which played a role in shaping its surface before freezing into a stagnant state.
This breakthrough highlights how seismic data can unravel planetary mysteries, even with limited instruments. It offers a glimpse into Mars’ dynamic past and the processes that shaped its terrain billions of years ago.
Implications for Planetary Science
This discovery offers a deeper understanding of Mars’ early tectonic activity and its transition to a geologically static state. It underscores the role of internal forces in shaping planetary surfaces, challenging the notion that external impacts are the dominant factor.
Future studies aim to gather more seismic data and refine models of Mars’ interior. By comparing Mars with Earth and other planets, scientists hope to uncover universal principles of planetary evolution.
Based on content from www.dailygalaxy.com and own research.