Why does Mars not look like the other planets?

Although all 4 are rocky / terrestrial planet located near the center of the Solar System, the physical composition of Mars has some differences compared to the other three planets.

In the modern view of the formation of planets in the Solar System, at the time when the Sun is still in pre-stellar state (without fusion reaction), clouds of gas dust (nebula) revolve around the Face. Heaven and there was a separation of material composition between clouds in "near" and "far" center of the system.

This leads to the planets being close to each other, after forming, there will be similar material composition.

Structure of Red planet differs from many Green planets.

But with Mars, there is a difference. Results of analysis of Martian rock samples sent by self-propelled robots show that the material composition of this planet is much different from Earth.

For example, the iron content of this planet's surface is twice as much as Earth's. It also contains more sulfur (S), potassium (K, Potassium), phosphorus (P) and chlorine (Cl) than our planetary shells.

This strange feature of Mars causes many astronomers to ask why?

There are many hypotheses. Among them is the idea that where Mars "was born" about 4.56 billion years ago is probably farther away from the center of the Sun than its current location. In other words, the Red planet has "migrated" into the Solar System so we can see it as it is today.

Kevin Walsh, planetary scientist at the Southwest Research Institute in Boulder County, Colorado, said: "We just started to feel" fine "with the idea that the planets have changed. His orbit, the ability is many times. The planets may not have been born where we currently see. "

But this idea only existed in theory. Only recently has it been demonstrated through planetary simulation models of other scientists. Stephen Mojzsis, a geologist at Colorado Boulder University (USA), found that Mars may have been born twice as far away from the Sun as it is today.

The hypothesis is that Mars was originally born in the asteroid belt, but was "dragged" inside by gravity, causing its size to be larger than Mercury.

Mojzsis collaborated with planetary scientist Ramon Brasser of Tokyo Institute of Technology (Japan), along with several other colleagues to run the Grand Tack planet simulator model . This is a model that simulates the process of changing the orbit of Jupiter (the largest solar system) and monitoring its influence on other planets, including Saturn and Mars.

In most simulated situations, in order to produce the Mars model of size and position today, it must form in orbit that is narrower than Earth's orbit, and slowly deviate out due to the Use of centrifugal force. However, these simulated situations do not explain the difference in material structure we mentioned above.

On the contrary, although the "risk" is only 2%, the situation of Mars emulation born in a position far away from twice the present explains the difference.

Specifically, that position lies within the asteroid belt that is quite close to Jupiter. In the process of flying close to the Sun, Jupiter's gravity "pulled" along Mars into the interior. This "dragging" caused Mars not to collect much material so it could be as big as Venus or Earth.

In fact, the mass of Mars is only 1/9 of the Earth and only a bit heavier than Mercury. If the "drag" doesn't happen, it is very likely that Mars is about the size of Earth or the present Venus.

Going back to the simulated situation, if Mars is formed in such a distance, it will receive less heat than the current situation. It means it is not warm enough to form a surface atmosphere, or to maintain liquid water, Mojzsis argues. Although collisions with meteorites may partially melt ice blocks.

But overall, the surface temperature of the Mars surface has not been sustained long enough for the germ to start as it does on Earth.

If not "dragged", Mars may not be as small as it is today.

However, this is just a computer simulation model. In fact, scientists will need more data to supplement the vacancy.

For example, we are not sure if the chemical composition of Venus and Mercury are similar to the Earth. This similarity only takes place on the theory of planet formation. And as stated, this theory does not explain why the Earth and Earth have differences in chemical composition. That means we still have a lot of unknown things about the nature of the planets.

But it is precisely because those unresolved things are the driving force for development science - more space research projects are needed such as bringing robots to Venus or Mercury to solve problems.