A friend brought a Mars photo for me to tell the truth and falsehood. He said that this is an image of the Mars surface taken by the American Mars probe . There are obviously rows of big trees growing on the yellow sand dunes, and there are bushes of plants similar to bushes scattered in the middle, which is really shocking!
There are rows of "big trees" on the dunes on the surface of Mars
First of all, this photo is real and has not been passed through PS. It was announced by NASA in 2010 and was a high-resolution camera equipped by the Mars Reconnaissance Orbiter (MRO) shot near the North Pole of Mars in April 2008. The picture width is about 1 kilometer and the pixel resolution is 30 cm.
If the Martian forest was real, the United States should have been announced to the public long ago, because this not only proves the existence of Martian life, but also is quite prosperous! But what’s interesting is that NASA has never said that there is life on Mars for more than ten years. Have they not paid attention to this photo?
Careful you must notice a strange phenomenon in the picture: the rolling sand dunes show rich light and shadow, and the sun shines from the northeast direction, but the towering "trees" have no shadow, and the black shadows of the "shrubs" are also very messy, and there are those in any direction.
"There must be something wrong!" You will say this with a clever mind. So, what's wrong?
Martian Pole is covered with dry ice
Martian is a bitter and cold place. Due to the distance from the sun, the annual average temperature on Mars' surface is only -63℃, which is even colder than the North and South Poles of the Earth; and the lowest temperature in the poles of Mars can reach -153℃, and even the air will be frozen. The North Pole of Mars is covered with ice and snow all year round. This is not ordinary water ice, but dry ice. Because it is too cold, about 3 to 4 trillion tons of carbon dioxide in the Martian atmosphere are frozen in winter, forming a transparent dry ice shell with a thickness of 1 meter on the polar surface.
Now we can conclude that in such a harsh environment, there are no tall trees on the surface near the North Pole of Mars, and even the lowest life cannot survive.
In fact, those "big trees" are traces of "soil and rock flow" left by collapsed sand dunes. The so-called "shrubs" have nothing to do with plants. They are actually piles of sand "fountains".
gravel is sprayed into the air by carbon dioxide gas
With the arrival of summer on the North Pole of Mars, the sunlight shines here more. The dark basalt sand and gravel under the transparent dry ice layer is easier to absorb heat energy, thereby heating the dry ice in the gap, which sublimates into carbon dioxide gas and gathers under the ice sheet. As the pressure becomes stronger and stronger, the gas is violently erupting, bringing out the underground sand and gravel dust and spilling it far away.
Dark basalt debris under the surface of Mars are scattered on the ice cover covered with dry ice. From a high point, it looks like a bush. These "shrubs" are connected in pieces, and we will think that they are forests scattered on the ice field.
Black basalt erupts and spreads on the surface of the ice field
This does not explain why rows of tall black shadows appear on the surface of Mars. They do look like giant trees. Are these trees also our illusion?
You are right, this is indeed our illusion. The neat rows of black are actually landslides on Mars dunes - of course, it is also related to dry ice.
The surface of Mars is extremely dry and there is no water here. Even if some scientists believe that there is abundant water ice under the Arctic surface, water ice is a dry mineral at a few dozen degrees below zero. Under the warm sunlight, the surface of the steep dunes is heated, and the dry ice in the cracks of the gravel rocks is sublimated into carbon dioxide gas, and the expanded gas makes the dunes loose.
Dry sand will collapse
Friends who have piled sand sculptures by the sea know that if you want to pile up a "castle", you need to keep the sand moderately wet; most dry and loose particles can only maintain a resting angle of 30°~37°; and if the sand is too wet, it will also cause collapse.
Steep inclined surfaces are more likely to occur in landslides
The gas after dry ice sublimation loosens the steep dunes, and the loose basalt gravel produces landslides under the action of gravity. Dark particles pour down from the top of the dunes and only spread to the surroundings until the bottom. We look down at this landslide, like big trees side by side.
Pseudo-color photos of the surface of Mars show landslides
If you rotate the diagram one by one angle and enlarge it partially, you can find that these "trees" are actually landslides that collapse from the top of the dunes and pour down along the grooves. However, some people who are interested in turning it upside down by 180 degrees with "ulterior motives", so our brains automatically match the images they see with familiar objects in their memory, thus creating an optical illusion, mistakenly thinking that they were rows of big trees.
Once the picture is reversed by 180 degrees, you will suddenly realize
Some friends will ask, aren’t the soil on Mars red? Why are those landslides black?
Black basalt is a type of volcanic rock widely present on Mars. The early geological activities of Mars were extremely active. A large number of volcanic magma gushed out to cover a wide area, many of which were weathered into black basalt class. The red on the surface of Mars is a large amount of iron oxide (Fe2O3) dust accumulation, which makes us mistakenly think that its underground is also red, but it is not.
