While scientists have been considering the idea of a human outpost on Mars, there is a fascinating question that remains: Could the Red Planet eventually collide with Earth?
In 2009, French astronomers Jacques Laskar and Mickael Gastineau investigated this in a study published in the journal Nature.
The scientists tested 2,501 possible scenarios on a supercomputer of how our solar system might evolve during the next five billion years.
Interestingly, they found that the smallest planet in our solar system, Mercury, could cause a chain reaction that could destabilise the orbits of neighbouring planets.
The gravitational pull of Jupiter might slowly deform Mercury’s orbit and force it to collide with the Sun or Venus in the future.
In one simulation, the resulting instability created conditions for Mercury, Venus or Mars to collide with Earth approximately 3.34 billion years from now.
Is Earth at risk of being ejected from the solar system?
Another threat, addressed in a more recent study published in Icarus in 2025, is the possibility of stars approaching our solar system.
In five billion years, the planet Earth has a 0.2% chance of being destroyed by collision with another planet or ejected from the solar system, according to research by Nathan Kaib and Sean Raymond.
Interestingly, Earth may have already survived such a catastrophic collision.
The idea that a Mars-sized body, called Theia, crashed into Earth some 4.5 billion years ago, spilling material that came together to create the Moon is currently the leading theory for the origin of the Moon.
In an interview, published this year, Laskar admitted that the likelihood of Earth’s collision with another planet is still not known precisely.
Fortunately, none of these scenarios poses an imminent threat to humanity.
