One of the loneliest species on Earth, living 2,800m underground and surviving on radioactive energy

In the universe there are countless planets, one of the important reasons why scientists believe that life can exist on many planets in the universe is because the environment where life can exist is much worse than we imagine.

The cold and dry polar regions, the hot and water-poor desert regions, are considered uninhabitable places for most life on Earth. But that is just in the normal thinking of people, on Earth, there are some creatures that can live in harsh environments, these environments are considered like hell for other creatures.

These extreme environments include high temperatures, high pressures, low temperatures, and high radiation. For example, some bacteria and archaea can survive in extreme environments such as hot springs, deep-sea hydrothermal vents, volcanic craters, and glaciers.

On Earth, there are some creatures that can live in harsh environments. (Illustration: ZME)

The hot water emitted from deep-sea hydrothermal vents is hundreds of degrees Celsius, but some special microorganisms and marine organisms can survive in this environment. These microorganisms rely on chemical reactions instead of photosynthesis for energy. They can use the energy of the eruptions, released sulfides, and other chemicals to carry out metabolic activities.

Among all life on Earth, the most resilient species discovered by mankind is the tardigrade (also known as the water bear), a small invertebrate that can survive in harsh environmental conditions such as high temperature, high pressure, low temperature and high radiation. Even in the radiation environment of the vacuum of outer space, it can still exist in a dormant state for a period of time.

Water bear. (Photo: ZME).

From the examples introduced above, it is not difficult to see that life can survive in harsh environments, mainly some special, simple and low-level microorganisms, even without sunlight and oxygen, they can still survive and have very strong adaptability.

70% of the Earth's surface is covered by ocean, although life is mainly distributed in shallow seas, scientists have also found traces of life in the deep sea thousands of meters away. Because the pressure in the deep sea is extremely high, life in the deep sea is very different from life in the shallow sea.

In addition to discovering life thousands of meters below the seabed, scientists have also discovered life 2,800 meters below ground.

In order to exploit mineral resources such as oil and gold buried deep underground, the deepest depth of man-made mines has exceeded 10,000 meters. When people mined for gold in these special areas, they discovered some unique life forms.

When people dig for gold in special areas, they discover some unique life forms. (Illustration: CNN)

In 2005, at the gold mine called "Mboneg" near Johannesburg, South Africa, a team of scientific researchers came here, in the gold mine cave there is a crack filled with underground water 2,800 meters below the ground, the researchers collected a large number of samples.

After analyzing the samples, scientists found that there were indeed many microorganisms in the groundwater. However, after excluding the sample data caused by microbial contamination on the ground, the results surprised scientists, because they found that there was only one species existing in this 2,800 meter deep underground fissure . In other words, this microorganism may have never come into contact with other species for a long time and lived in a completely isolated world.

Because they are found in gold mines, they are often called 'gold mine fungi' . These microorganisms are rod-shaped, averaging about 4 microns in length, and are capable of moving and forming spores.

Because they are found in gold mines, they are often called 'golden mineral mushrooms'. (Illustration: ZME).

The temperature of the underground water in the crack where the gold mineral bacteria live is always above 60 degrees Celsius all year round, the pH is about 9.3, there is no sunlight all year round and no oxygen. Most life on Earth cannot survive in such an environment, but the gold mineral fungus can survive and grow normally.

So how can the gold-mining fungus survive in underground cracks 2,800 meters deep? Research results show that in the environment where the gold-mining fungus lives, there are some radioactive elements , and part of the energy released when these radioactive elements decay meets the survival needs of the gold-mining fungus . The gold-mining fungus can use this energy to synthesize the organic compounds they need from water, carbon dioxide, sulfide and nitrogen in the rock to maintain metabolism.

It must be said that the ability of these life forms to survive in extreme environments is amazing, these environments may be hellish for other life forms, but for those life forms that have adapted to these environments, they have found a unique way to survive. Studying these extreme life forms helps humans better understand the origin and evolution of life, search for life outside of Earth and develop new biotechnology.