In February 2019, the Israeli spacecraft "Genesis" landed on the moon with water bears in the "Quiet Sea" area, and now it has been almost five years.
A brief look at "water bears"
Many netizens have heard of water bears and have the impression that this is the most survivable creature on the planet, but they have not learned about it specifically, so the following content should not be missed.
The tardigrades are collectively referred to as the tardigrades composed of more than 1,000 species, the survival history can be traced back to 500 million years ago, the vast majority of the tardigrades are 0.3~0.5 mm long, invisible to the naked eye, but under the microscope, the appearance of the tardigrades is clearly visible, the body is bloated, there are probes on the tubular mouth, there is a puncture function, and they feed on plants, algae, bacteria and small invertebrates.
The water bear has a wide range of distribution, from the South Pole to the North Pole, whether it is a volcano or a glacier, or the Mariana Trench, there are its figures, but if you have a choice, the water bear still prefers a water environment, and the appearance is similar to a bear, so the combination of "water" and "bear" is named "water bear".
The survival temperature of water bears is 151 °C ~ minus 272.8 °C, it is worth noting that the absolute zero of the universe is -273.15 degrees Celsius, which alone is enough to show how strong the survival ability of water bears is.
In addition, tardigrades also have excellent drought tolerance, they will adjust their water content according to the surrounding environment, usually in 3% ~ 85%, when in the desert and other extremely water-scarce environments, tardigrades will let their bodies enter a special state when the water content is less than 3%, which is called "hidden ecology" in modern science.
When the snake is below 6°C, the body's ability to move will be greatly reduced, so the snake needs to find a hidden place to enter a special state, which we call "hibernation".
In addition to snakes, there are many animals on the earth that have evolved special skills in special environments, such as African lungfish in the dry season, with the help of mucus on the body surface to enter a dormant state, without eating or drinking for months, or even more than 1 year, when the rainy season comes, they will recover.
For example, scientists found a hidden water bear under the rocks of the Sinai Desert, and after investigation, there has never been a drop of rain in this place for 25 consecutive years, but when the hidden water bears come into contact with water, they can complete hydration and revive.
Even so, the hidden water bears are not dead, and in addition, the water bears can withstand 600 megapascal pressures, even in the deepest part of the Mariana Trench, and even under the bombardment of atomic bombs, they can withstand 5,700 Gray radiation.
In order to further verify the survivability of water bears in space, scientists conducted a series of measurements.
In 2007, the tardigrades were taken out of Earth to be exposed to the cosmic environment, returned to Earth 10 days later, and after hydration, about 68% of the tardigrades were rejuvenated.
In 2011, tardigrades and other microbes were exposed to space again, and the results were similar to the last time.
In other words, water bears can indeed survive 5000 Gray gamma rays or 6200 Gray heavy ion radiation, while human beings who are exposed to 5~10 Gray radiation are in great danger to their lives.
Why are water bears so strong in survivability?
Scientists have studied the genes of tardigrades, and found that they have damage inhibitory proteins that can be used to protect against harmful radiation, and if this substance can be transferred to humans, it will certainly help us move towards the sea of stars.
What happened to the tardigrades that landed on the moon in 2019?
In February 2019, Israel carried out a lunar landing program, and by the way, it also brought water bears on it, but when entering the lunar orbit to prepare for landing, the "Genesis" engine failed, resulting in a failed landing on the moon and the probe crashing on the surface of the moon at high speed.
The tardigrades are divided into two parts, one in a special device called the "Moon Library" and the other in a special epoxy resin.
Are the tardigrades in the "Moon Library" still alive?
It is a pity that the tardigrade group is extinguished, because after many experimental tests, the impact high pressure that the tardigrade can withstand is 1.01GPA, no matter how the limit, once the value exceeds 1.14GPA, it will not work, and the impact high pressure generated by the Israeli probe falling to the moon exceeds 1.14GPA, so the water bears in the "lunar library" must be "wiped out".
And what about the other part of tardigrades?
Scientific experiments have proved that although the tardigrade has advanced environmental adaptability, it cannot survive for a long time, that is, for example, the tardigrade can survive for 10 days in an environment of -200°C, you can say that the tardigrade can resist -200°C, but it does not mean that it can survive for a long time.
The temperature difference between day and night on the moon is large, the temperature can reach 127 °C during the day, and the temperature drops to -183 °C at night, scientists have also done tardigrades to resist high temperatures, and found that when the temperature rises to 63.1 °C, the number of tardigrades dying every day accounts for up to 50%, in short, even if the remaining tardigrades are not eliminated by the impact of the detector, they cannot survive on the moon for a long time, so after nearly 5 years, these tardigrades have died.