While Earth is already facing the threat of asteroids, a new study reveals that Mars could be even more vulnerable to these space objects. This discovery could have major implications for future missions and the potential human colonization of the red planet.
A relatively young impact crater observed by NASA's Mars Reconnaissance Orbiter. Mars could face twice as many devastating meteorite impacts as Earth. In the event of a collision, asteroids are likely to cause more damage on Mars due to its thinner atmosphere.
Credit: NASA/JPL-Caltech/Univ. of Arizona
Asteroids are a well-known threat to Earth, as evidenced by the Chelyabinsk impact in 2013. However, Mars, located near the main asteroid belt between Mars and Jupiter, could face an even greater danger. Researchers have discovered that the red planet could receive twice as many potentially hazardous asteroids as Earth.
To quantify this threat, astronomers from Nankin University used computer models simulating the movements of thousands of asteroids over millions of years. These simulations revealed that each year, about 52 large asteroids approach Mars, compared to only 20 for Earth.
The Yarkovsky effect, a force generated by the re-radiation of solar energy by asteroids' surfaces, plays a crucial role in these simulations. This effect causes asteroids to drift into void zones in the main belt, where gravitational interactions with Jupiter or Saturn can send them toward the inner planets, including Mars.
NASA missions have already observed the impacts of some of these asteroids. For example, a meteorite impact on December 24, 2021, caused a magnitude 4 earthquake detected by the InSight lander on Mars. These events underscore the need to consider the asteroid threat for future missions and potential human colonies on Mars.
Beyond the danger, these asteroids also offer scientific opportunities. Studying asteroids close to Mars could improve our understanding of the Martian environment and the evolution of the inner Solar System. According to researchers, some of these asteroids could even be visible from Earth in early 2025, when Mars will be aligned with our planet on the same side of the Sun.
This study highlights the importance of monitoring not only near-Earth asteroids but also those threatening Mars. As the exploration and potential colonization of Mars advance, understanding and mitigating these risks will become essential for the safety and success of these missions.