Documentary "Planet" 2 Earth and Mars

The second episode of "Planet" continues the question of the first episode, why Mars ended up being cold and dry like the Earth. This episode mainly talks about Earth’s sister planet-Mars.

Billions of years ago, Mars, like Earth, had volcanoes, lakes and oceans. These inferences benefit from exploration by space probes. The probe has sent back photos of 80% of the surface of Mars. We can clearly see the largest volcano in the solar system, Olympus Volcano, which is 21,171 meters high. We can also see the huge basin, more than 9,000 meters deep, and the magnificent Eicher Deep valley and so on. Various washed-out landforms prove that Mars once had rivers and oceans. At the same time, the Curiosity rover also landed on Mars, and soil samples collected in the basin were analyzed and found to contain 2% water.

What causes the completely different destinies of Earth and Mars?

Based on the number of craters on the moon and the detection of meteorites brought back to the earth, it can be concluded that about 3.8-3.9 billion years ago, both the earth and Mars suffered a large number of meteorite impacts, and Mars had more than one-third of its surface scars Tired, Mars was pushed to the brink of death. After calculations, these meteorites are mainly caused by Neptune's outward migration, causing the Kuiper Belt asteroids in the outer solar system to change their orbits and fly towards the inner solar system.

The Earth also suffered an impact, but in this least optimistic situation, the most remarkable feature of the Earth appeared - life. There is evidence that life began to appear on the earth about 3.8 billion years ago. Somewhere on the earth, changes in its own chemistry transformed into changes in biochemistry. How such a transformation occurs has always been a mystery, but it is generally believed that volcanic pools or submarine hot springs are most likely to produce such changes. So scientists began to look for such places on Mars and launched new detectors. In 2017, they discovered the characteristics of submarine hot springs and 400 meters of mineral deposits in the Eridani Basin. So maybe there really was life on Mars.

But the real cause of Mars' death may come from the interior of Mars.

Mars had habitable conditions for hundreds of millions of years in the Noahic era. 3.5 billion years ago, Mars entered a colder era, the Hesperian period. The once flowing water was frozen, and during this period, Mars experienced frequent volcanic movements, and the melting ice led to catastrophic floods. The flood flowed all the way down to the Eches Valley, eventually forming a waterfall more than 4,000 meters high. This should be the largest waterfall in the history of the solar system.

In 2014, NASA launched the "Mars Atmospheric Volatile Evolution" probe and found that the Martian atmosphere is disappearing at a speed of 2 kilometers per second. Without the protection of the atmosphere, the temperature of Mars cannot be maintained at a suitable temperature.

So what caused Mars’ atmosphere to dissipate, while Earth’s atmosphere remained intact? The main reason is the solar wind. Without the protection of the magnetic field, the earth's atmosphere will also be blown away by the solar wind. The aurora we see are the beautiful colors emitted by electrons in the solar wind as it passes through the magnetic fields of the North and South Poles. The formation of the protective shield magnetic field comes from the interior of the earth.

There is a layer of hot molten iron in the outer core of the earth. The convection generated inside can cause the molten iron to rise. The rotation of the earth causes the molten iron to rotate with it. This spiral flow generates electric current, just like a generator. , producing a magnetic field that protects the atmosphere from solar wind interference. Such a structure once existed inside Mars, but between 3.5 and 4 billion years ago, Mars' engine shut down, the solar wind blew away the atmosphere, and Mars became colder and colder.

Over the next billions of years, life on Earth began to transform the Earth. Primitive algae began to synthesize the acidity of the ocean and replace methane with oxygen. Sixty million years ago, complex organisms began to appear under the influence of oxygen.

If we continue to delve deeper into the differences between Mars and the Earth, we have to go back to the beginning of their birth. The Earth happened to be in a rocky area, so the Earth is about twice the size of Mars. The smaller size indicates that the Earth is The core is smaller and cools faster, which is why Mars' engines shut down earlier.

This is the completely different fate of the two sister planets Earth and Mars. However, mankind has not stopped. Musk still proposed a great plan to move to Mars and start mankind's interstellar journey. Therefore, he invented the recyclable rocket.

It is said that the cultural gene of white people is the gene of colonization, so they want to continue to expand, but looking at the stars in the distance makes people not want to step forward to take a peek.

However, I hope that we can protect the earth that gave birth to us while exploring the outside. We do not hope that one day the original intention of the interstellar journey will be forced by the destruction of our own homeland, like the earth. This planet with rich species and beauty may be the only one in the vast universe.