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TORONTO: Space scientists and astronauts are much less likely to find life in the outer solar system, home to the four “giant” planets: Jupiter, Saturn, Uranus and Neptune, according to a study.
That’s because a team of Canadian scientists has discovered that the subterranean ocean of Titan, Saturn’s largest moon, is likely a non-habitable environment, meaning any hope of finding life on the icy world is dead.
“Unfortunately, we will now have to be a little less optimistic when looking for extraterrestrial life forms within our own solar system,” said astrobiologist Catherine Neish, a professor of Earth sciences at the University of Western Ontario in Canada.
“The scientific community has been very excited about the discovery of life on the icy worlds of the outer solar system, and this finding suggests that it may be less likely than we previously assumed,” Neish added.
Identifying life in the outer solar system is a major area of interest for planetary scientists, astronomers, and government space agencies like NASA, largely because many icy moons of giant planets are thought to have large water oceans. liquid below the surface.
Titan, for example, is believed to have an ocean beneath its icy surface that is more than 12 times the volume of Earth’s oceans.
In the study, published in the journal Astrobiology, Neish and his team attempted to quantify the amount of organic molecules that could be transferred from Titan’s organic-rich surface to its subsurface ocean, using data from impact craters.
Comets that have impacted Titan throughout its history have melted the moon’s icy surface, creating pools of liquid water that have mixed with organic matter on the surface. The resulting melt is denser than its icy crust, so heavier water sinks through the ice, possibly to Titan’s subterranean ocean.
Using assumed rates of impacts on Titan’s surface, the team determined how many comets of different sizes would collide with Titan each year throughout its history. This allowed researchers to predict the flow of water carrying organic substances traveling from Titan’s surface to its interior.
Neish discovered that the weight of organic matter transferred in this way is quite small, no more than 7,500 kg/year of glycine, the simplest amino acid, which forms proteins in life.
This is approximately the same mass as that of a male African elephant. (All biomolecules, such as glycine, use carbon, an element, as the backbone of their molecular structure.)
“One elephant per year of wisteria in an ocean 12 times the volume of Earth’s oceans is not enough to support life,” Neish said.
“In the past, people often assumed that water is synonymous with life, but they ignored the fact that life needs other elements, particularly carbon.”
Other icy worlds (such as Jupiter’s moons Europa and Ganymede, and Saturn’s moon Enceladus) have almost no carbon on their surfaces, and it’s unclear how much could be obtained from their interiors.
Titan is the most organically rich icy moon in the solar system, so if its underground ocean is not habitable, it does not bode well for the habitability of other known icy worlds.
“This work shows that it is very difficult to transfer carbon from Titan’s surface to its subsurface ocean; basically, it is difficult to have both the water and carbon needed for life in the same place,” Neish said.
That’s because a team of Canadian scientists has discovered that the subterranean ocean of Titan, Saturn’s largest moon, is likely a non-habitable environment, meaning any hope of finding life on the icy world is dead.
“Unfortunately, we will now have to be a little less optimistic when looking for extraterrestrial life forms within our own solar system,” said astrobiologist Catherine Neish, a professor of Earth sciences at the University of Western Ontario in Canada.
“The scientific community has been very excited about the discovery of life on the icy worlds of the outer solar system, and this finding suggests that it may be less likely than we previously assumed,” Neish added.
Identifying life in the outer solar system is a major area of interest for planetary scientists, astronomers, and government space agencies like NASA, largely because many icy moons of giant planets are thought to have large water oceans. liquid below the surface.
Titan, for example, is believed to have an ocean beneath its icy surface that is more than 12 times the volume of Earth’s oceans.
In the study, published in the journal Astrobiology, Neish and his team attempted to quantify the amount of organic molecules that could be transferred from Titan’s organic-rich surface to its subsurface ocean, using data from impact craters.
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Using assumed rates of impacts on Titan’s surface, the team determined how many comets of different sizes would collide with Titan each year throughout its history. This allowed researchers to predict the flow of water carrying organic substances traveling from Titan’s surface to its interior.
Neish discovered that the weight of organic matter transferred in this way is quite small, no more than 7,500 kg/year of glycine, the simplest amino acid, which forms proteins in life.
This is approximately the same mass as that of a male African elephant. (All biomolecules, such as glycine, use carbon, an element, as the backbone of their molecular structure.)
“One elephant per year of wisteria in an ocean 12 times the volume of Earth’s oceans is not enough to support life,” Neish said.
“In the past, people often assumed that water is synonymous with life, but they ignored the fact that life needs other elements, particularly carbon.”
Other icy worlds (such as Jupiter’s moons Europa and Ganymede, and Saturn’s moon Enceladus) have almost no carbon on their surfaces, and it’s unclear how much could be obtained from their interiors.
Titan is the most organically rich icy moon in the solar system, so if its underground ocean is not habitable, it does not bode well for the habitability of other known icy worlds.
“This work shows that it is very difficult to transfer carbon from Titan’s surface to its subsurface ocean; basically, it is difficult to have both the water and carbon needed for life in the same place,” Neish said.