The Outlandish Scenario of Mars Being Closer to Earth: Celestial Mechanics Reimagined
Every year, a fascinating myth surges around August, stating that Mars is moving closer to Earth and will eventually appear as large as a full moon in the night sky. This claim, while utterly fiction, prompts us to ponder: What would change if Mars were indeed much closer to our planet?
Celestial Mechanics and Our Planetary Partnerships
Celestial mechanics govern the orbits of celestial bodies, which are incredibly complex and subject to subtle changes over millions of years. These changes often create resonant orbits, where bodies align in predictable patterns due to their gravitational interactions.
Orbital Resonances: Key Examples
Mercury and Venus have a 5:2 resonance, meaning Mercury completes 5 orbits in the time it takes Venus to complete 2.55 orbits. For Earth and Mars, the ratio is slightly less than 2:1, and for Mars and Jupiter, it's approximately 7:1. The asteroid belt is intriguingly resonant with both Jupiter and Mars, often meeting at the Lagrange points, where they trade positions. This resonance is due to a slightly elliptical orbit where the asteroids are at their perihelion when directly between Jupiter and the Sun.
Changes in Mars' Orbit Over Time
Historically, Mars has been closer to Earth. However, during opposition, Earth pulls on Mars, causing its orbit to shift. In turn, Earth is also affected by this gravitational tug, causing its orbit to adjust ever so slightly. Over millions of years, these small shifts cause tidal forces on the Sun, leading to a gradual increase in the orbits of all planets. This process is incredibly slow, adding less than a meter per century to the orbits.
Impact on Mars' Climate and Suitability for Colonization
If Mars were closer to Earth, several key factors would change, drastically impacting its climate and potential for human habitation.
Warmer Climate for Mars
With Mars closer to the Sun, the planet would likely experience a warmer climate. Early in Mars' history, it had a thicker atmosphere and more liquid water, and a closer proximity to the Sun could foster similar conditions again. However, this warming effect would be accompanied by increased solar wind, stripping away the atmosphere even more quickly than it already is being lost.
Atmospheric Lifespan and Human Colonization
To address the thinning atmosphere, one potential solution is to create a dipole magnetic generator at Lagrange point L1 to block the solar wind. This mechanism, driven by a nuclear reactor and requiring a maintenance crew, is both expensive and complex. An alternative and potentially more feasible approach is to deploy thousands of smaller magnetic generators on the Martian surface. These solar-powered generators could gradually thicken the atmosphere, making Mars habitable over a period of hundreds of thousands of years. Despite the long-term nature of this process, it is a viable strategy for eventual colonization.
Current Colonization Potential
Even without the need for atmospheric thickening, Mars already has the necessary resources for human survival. Carbon dioxide levels on Mars can be managed through surface generators, allowing for the thickening of the atmosphere and the eventual establishment of a colony. This colony could function with gas masks and parkas rather than pressure suits, making life on Mars more manageable as the atmosphere thickens.
Conclusion
The hypothetical scenario of Mars being closer to Earth is an intriguing one, bringing to light the complex nature of celestial mechanics and their impact on our solar system. While the warming of Mars would initially seem beneficial for colonization, the increased solar wind would make it more difficult to maintain an atmosphere. Nonetheless, the development of artificial magnetospheres could provide a sustainable solution, allowing us to make Mars habitable and eventually colonize it.