Mysterious and enticing--a true Wonderland world--Mars has sung its scientific siren's song for years to those who seek to understand its many long-held secrets. This small, rocky world with an intriguing red hue, gets its rusty color from the large amount of iron oxide that coats its surface. Much of this small world's charm comes from its reputation of being the happy abode of "little green men"--Earth's neighboring planet that plays host to life as we know it. However, Mars has many captivating features and bewitching mysteries, in addition to the somewhat dated idea that it is the most likely world in our Solar System--other than our Earth--to host living creatures. The duo of small potato-shaped Martian moons, Phobos and Deimos, are frequently considered to be captured asteroids that the Red Planet's gravity snared when they were making an ancient and unfortunate journey through interplanetary space from their place of birth in the Main Asteroid Belt, located between the orbits of Mars and Jupiter. The duo of rocky objects now circle their adopted parent-planet--at least, for the time being. However, in July 2016, a team of astronomers proposed an alternative viewpoint, suggesting that the two little moons were born from an ancient impact on the Martian surface by a crashing primordial object--along with many other now long-lost little moons.

Ever since their discovery in 1877, Phobos and Deimos have both bewildered and bewitched astronomers trying to answer the question of how Mars ended up with its duo of misshapen little moons. However, this perplexing riddle might have been solved by a multidisciplinary study conducted by French, Belgian, and Japanese scientists.

Astronomers have for years contemplated two competing hypotheses explaining the origin of the Martian moons. The first proposes that Phobos and Deimos are, indeed, escapees from the Main Asteroid Belt. Alas, this viewpoint begs the question of why they should have been so cruelly captured by their adopted parent-planet in the first place. An alternative theory points to the possibility that the moons were born from the debris left by a violent collision between Mars and a primordial protoplanet--a baby planet still under construction. However, this theory also suffers from uncertainty because it does not explain precisely how this particular tragic mechanism gave rise to Phobos and Deimos.

"A major difficulty has been to explain why a giant impact on Mars would have left two moons so different from our own Moon, a huge single mass, that also formed from Earth undergoing such an impact," explained Dr. Sebastien Charnoz in a July 4, 2016 Centre National de la Recherche Scientifique (CNRS) Press Release. Dr. Charnoz is a planetary scientist at the Institut de Physique Du Globe De Paris (IPG) who contributed to the new research.Happy New Year 2020 Greetings

The Giant-Impact Theory, alternatively termed the Theia Impact, or Big Splash Theory, proposes that Earth's Moon was born from the debris remaining from a catastrophic collision, that occurred about 4.3 billion years ago, between the primordial Earth and an unfortunate protoplanet, that was about the size of Mars. The Earth's Moon-forming collision would have occurred when our Solar System was still forming during the Hadean eon. The Hadean eon occurred about 20 to 100 million years after our Solar System emerged from its frigid, dark natal cloud of gas and dust. The doomed impacting protoplanet, often called Theia, received its name in honor of a Titan in Greek mythology who was the mother of Selene, the Moon goddess. An analysis of lunar rocks, published in 2016, indicates that this catastrophic crash was a direct hit--causing a thorough mixing of both Earth-stuff and Theia-stuff. The Giant-Impact Theory is the favored scientific explanation for the birth of Earth's Moon.

When a moon is in an orbit around its parent-planet, all is well--just as long as the gravity that is holding the moon together in one piece exceeds the powerful, relentless pull of its planet. Alas, if a moon wanders too close, and the tidal forces of the parent-planet exceed the gravitational bind of the unlucky moon, the moon will fall apart. This is termed the Roche limit. Earth's relatively large Moon is a very fortunate natural satellite, and the limit here is a bit under 10,000 kilometers--while our Moon is a safe 385,000 kilometers away from our planet.

Alas, this is not the case with Phobos and Deimos. Phobos, the larger of the duo of little Martian moons, at 22 kilometers in diameter, is lazily tumbling towards Mars and will approach the Roche limit in about 20 million years. At this tragic point, it will shatter into fragments that will ultimately form a spectacular ring around its planet. Only Deimos will remain--bereft of its companion. Deimos is the smaller moon of the pair, and circles its parent-planet further out. This last remaining little moon will be a lonely object lingering in the Martian sky at this sad point--but it was not always thus. The new 2016 study suggests that Mars once possessed a very complex system of many moons.

In order to shed new light on the mysterious origins of the surviving duo of Martian moons, the researchers conducting this study combined their expertise in astrophysics, planetary science, computer science, and mathematics in order to create complex supercomputer models. The models ran a range of hydrodynamic and numerical simulations able to recreate the sequence of ancient events. Their findings strengthen the hypothesis that a horrific blast in the past formed the moons of Mars--originally a collection of moons and moonlets.

For a very long time, planetary scientists favored the scenario that the duo of potato-shaped Martian moons were probably snared asteroids. However, the pair's circular orbits at the equator indicated otherwise. The orbits of the little moons suggested that they had really formed from a giant impact billions of years ago. The new research, published in the July 4, 2016 issue of Nature Geoscience, proposes that a massive 2,000 kilometer protoplanet crashed into the primordial Mars. The horrendous impact resurfaced most of the Martian surface and hurled a mass of debris, more than 100 times the mass of both Phobos and Deimos, into orbit around the Red Planet.

Mars may be circled by many moons smaller than 160 to 330 feet in diameter, and a ring of dust has been predicted to circle Mars between Phobos and Deimos.