Our Solar System Lacks a Super-Earth and That Might Be a Good Thing

Planetary scientists have explored a hypothetical scenario in which a super-Earth existed within our solar system, situated between the orbits of Mars and Jupiter. According to recent simulations conducted by Emily Simpson and Howard Chen, planetary scientists at the Florida Institute of Technology, such a planetary configuration could have drastically destabilised the climates and orbits of neighbouring planets, including Earth.

Gravitational Instability and Climate Disruption

The findings, as per a Space.com report, highlight that super-Earths, which are commonly observed in exoplanetary systems, are notably absent from our solar system. These planets, larger than Earth but smaller than Neptune, are a frequent occurrence in the Milky Way. The researchers simulated various iterations of a super-Earth within our solar system to assess its gravitational effects on inner rocky planets like Earth, Venus, and Mars.

The study is said to have revealed that the presence of a super-Earth, particularly one with a mass ranging from 10 to 20 times that of Earth, would have caused significant disruptions. Chen stated in his interview with Space.com that the gravitational pull of such a planet could push smaller rocky planets into eccentric orbits or tilt their trajectories. These unstable orbits would lead to extreme climatic conditions, including erratic transitions between ice ages and periods of intense warming.

Chen told the publication that while the configuration we observe in our solar system is uncommon, the presence of a super-Earth in this region could have made Earth’s orbit highly unstable, jeopardising its habitability.

Implications for Life in Exoplanetary Systems

The findings suggest that even planets located in the habitable zones of other star systems may face significant challenges to sustaining life if they share their region with massive super-Earths. The instability introduced by such neighbours could hinder the evolutionary processes that require relative climatic stability.

While a slightly larger planet near Mars might lead to harsher seasonal variations on Earth, conditions for life could still persist. However, the researchers emphasised that the absence of a super-Earth near Mars and Jupiter may have been critical in enabling Earth’s current hospitable environment.