(ORDO NEWS) — The discussion about the formation of the satellites of the Red Planet continues. Computer modeling has refuted the assumption put forward last year about the satellite – the progenitor of Deimos and Phobos.
Mars has only two moons, Deimos and Phobos. Their origin raises many questions among astronomers. According to one hypothesis, once upon a time they were one body. And now computer simulations have shown that in this case, two satellites would have collided long ago and formed a new system of satellites
Deimos and Phobos are very different from the Moon we are used to. They are ten times smaller and far from spherical.
The diameter of Phobos, which is closer to the planet, is 22.7 kilometers, and Deimos is 12.6 kilometers. For comparison, the diameter of the moon is 3474.8 kilometers.
They are so jagged in shape that astronomers have historically considered them to be large asteroids of spectral type D that came from the Kuiper Belt, a belt of small bodies beyond the orbit of Neptune, where Pluto also flies. This assumption was partly confirmed by the similarity of the spectra of satellites and class D astroids.
Later, a giant impact hypothesis arose (Giant Impact Hypothesis) , similar to the generally accepted hypothesis about the origin of the moon. It is believed that our satellite was formed billions of years ago from the debris from the collision of the Earth with a massive object.
Apparently, in the case of Mars, the debris did not fuse into a single body, but formed two satellites. And last year, it was suggested that in that collision, one primary satellite was still formed, which later broke up into Deimos and Phobos.
The new progenitor satellite hypothesis was called the ring-moon recycling hypothesis . The authors suggested that between one and 2.8 billion years ago, the progenitor satellite collapsed due to tidal forces or from a collision.
The debris formed a ring from which Deimos and Phobos were later formed. An analysis of their movement showed that in the past the orbits of the satellites intersected.
Other astronomers have criticized the study. First, the intersection of the orbits was obtained only for specific parameters of the tidal interaction.
Secondly, in such a short period of debris, the ring would not have had time to completely disappear. Critics included Ryuki Hyodo , a researcher at the Japan Aerospace Exploration Agency (JAXA) .
To test the hypothesis, Hyodo and his colleagues took as a basis the assumption that Deimos and Phobos were indeed one body, and then, using calculations and computer simulations, reproduced the evolution of the system of Mars’ satellites.
Their calculations and models disproved the progenitor satellite hypothesis. If Deimos and Phobos were fragments of the same body, they would have collided again within 100,000 years, forming a ring around the Red Planet that would still be seen today.
These results have added fuel to the debate about the origin of the Martian satellites.
However, many world agencies are planning space missions to the moons of Mars. In particular, NASA , JAXA and the European Space Agency are working on the MMX (Martian Moons eXploration) mission vehicle, which will bring samples from Phobos to Earth.
Analysis of such a sample will help resolve some questions about the formation of these satellites.
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