Unlike the Moon, which is part of Earth, Mars’ two moons, Phobos and Deimos, have a rather “dark” nature.
According to Live Science, a research team led by Professor Sonia Fornasier from Paris Cité University (France) analyzed a series of previously unpublished images from the Mars Express spacecraft – European Space Agency (ESA).
These 300 images intricately capture the features of Phobos, the larger of Mars’ two moons.
Mars’ moons may be “invaders” from the outskirts of the Solar System – (Image: NASA/BBC SKY AND NIGHT MAGAZINE).
Optical measurements indicate that Phobos’ surface may be porous, resembling sand, and lacks an atmosphere. Furthermore, this surface may be covered by a thick layer of oddly grooved dust particles, leading to uneven reflection of sunlight.
These characteristics are not similar to other moons in the Solar System but rather resemble those of comets belonging to the Jupiter family, meaning comets whose orbits are influenced by Jupiter’s gravitational pull.
Additionally, previous studies have shown that Phobos does not have a similar origin to Earth’s Moon.
The Moon is believed to have formed from debris following a collision between early Earth and the hypothetical planet Theia, thus sharing components similar to present-day Earth. However, the composition of Phobos is entirely different from its parent planet, making it a “captured moon.” In the most plausible scenario, Phobos must be a comet disguised as a moon.
These findings also have implications for Deimos. If Phobos was once a comet, then Deimos could also be a comet.
In fact, the authors suggest that the two moons might have once been a single comet consisting of two distinct lobes, which were torn apart by Mars, subsequently becoming trapped in orbit and becoming moons of this planet.
Referring to Mars’ moons as having a “dark” origin is because most comets in the Solar System come from the Kuiper Belt or the Oort Cloud, which are distant structures in the dim outskirts of the star system.
This discovery still requires final confirmation. Fortunately, the MMX spacecraft from Japan – set to launch this year in a mission in collaboration with NASA – will head towards Phobos and Deimos to collect samples, promising intriguing answers.
