Is life only on Earth? The wider universe is a waste of space [Now in space]
"If life exists only on Earth, the wider universe is a waste of space."
This is what American astronomer Carl Sagan said. It was a question of whether life exists only on Earth in the wider universe. Although life has not yet been found on other celestial bodies besides Earth, it means that there is a good chance that life exists on other celestial bodies and in galaxies.
One clue has been found to this question. Recently, the National Aeronautics and Space Administration (NASA) announced that it analyzed rocks and dust collected from the asteroid Bennu and sealed and brought back to Earth, and found that they contained amino acid and DNA/RNA information.
Amino acids, when linked, form proteins, which are the basis of life. DNA and RNA are the basics that pass down genetic information. This means that there are sufficient conditions for life to be born.
The OSIRIS-REx spacecraft is collecting samples from the asteroid Bennu in 2020. [Photo = NASA]
NASA's OSIRIS-REx spacecraft collected samples from the asteroid Bennu and brought them to Earth in September 2023. Bennu is known as a primitive celestial body that was formed in the early days of the solar system's formation about 4.5 billion years ago. It holds an important key to studying the early state of the solar system. It is considered a solar system time capsule.
Analysis of the samples brought to Earth confirmed amino acids (14 of the 20 that life on Earth uses to make proteins) and bases that life on Earth uses to store and transmit genetic instructions in more complex terrestrial biomolecules.
In addition, NASA explained that an exceptionally high concentration of ammonia was detected in the Bennu sample. NASA explained that ammonia is important for living things because when the right conditions are created, it can react with formaldehyde to form complex molecules such as amino acids.
Ammonia provides nitrogen atoms necessary for amino acid synthesis. Formaldehyde acts as an intermediate in certain metabolic pathways. These interactions are what drive the complex chemical reactions in living organisms.
Amino acids are the "Lego blocks" of proteins. Amino acids link together to form polypeptide chains, and these chains fold or assemble to form proteins. Proteins are the basis of all biological functions.
The building blocks of life found in the Bennu sample have been found in other meteorites that have previously fallen to Earth. The difference between the Bennu sample and the previous meteorite is the "contamination."
The Bennu sample was brought to Earth sealed in space on a spacecraft. It was not contaminated by the atmosphere. It is a pure sample. In contrast, the previous meteorite was inevitably contaminated by the Earth's environment during its passage through the atmosphere and at various levels.
"The clues we are looking for are so minute that they can easily be destroyed or altered by exposure to the Earth's environment," said Danny Glavin, chief scientist at NASA's Goddard Space Flight Center. "The Bennu sample was brought to Earth sealed in a spacecraft, so it is a pure sample."
Here, traces of 11 minerals were discovered in the Bennu sample, and it was confirmed that these minerals formed salt dissolved in water and evaporated over a long period of time, leaving the salt as a solid crystal. The
asteroid Bennu sample collected by the OSIRIS-REx spacecraft in 2020 arrived on Earth in September 2023. [Photo = NASA]
Jason Dworkin, NASA's OSIRIS-REx project scientist, said, "This analysis of the Bennu sample by OSIRIS-REx adds a big change to our understanding of the solar system, which has a rich potential for life." He asked an interesting question, "Why have we only seen life on Earth so far and not elsewhere?"
Meanwhile, the asteroid Bennu is about 500m in diameter and orbits the Sun with a 1.2-year cycle. It moves between the orbits of Earth and Mars and approaches Earth about every six years. It is known to preserve organic matter and minerals from the early solar system.
The OSIRIS-REx probe was launched in September 2016 and arrived at Bennu in December 2018. It collected samples in October 2020 and dropped the capsule containing the samples in the Utah desert in the United States on September 24, 2023.
The results of this study do not show evidence of life, but are considered a groundbreaking discovery because they imply that the conditions necessary for the emergence of life were widespread throughout the early solar system.
"The OSIRIS-REx mission has expanded our understanding of the beginnings of our solar system," said Dr. Nikki Fox of NASA. "Asteroids provide a time capsule of our Earth's history, and Bennu samples are key to understanding what ingredients existed in the solar system before life began on Earth."
This discovery is a separate issue from whether it could have led to the evolution of life. The Earth began with primitive life and evolved through evolution, eventually leading to the birth of advanced intelligent life forms, humans.
This was possible because Earth was located in the so-called "habitable space", which is the right distance from the star (the Sun), and had the right temperature and the right amount of liquid water. This is
one of the reasons why space scientists are looking for "habitable" planets at the right distance from other star systems and are concerned about the presence of liquid water there.
The significance of this discovery is interpreted as the possibility that other planets similar to Earth could have evolved as a result of impacts by asteroids like Bennu, which contain the 'seeds of life', and if there were the right distance from the star, the right temperature, and the right amount of liquid water.
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