Location is one of the most significant unanswered scientific questions: if life exists beyond Earth, where is it?
Even though you may believe the answer to be “very far away,” it may be considerably closer to home than we initially believed.
There are currently nearly 300 moons in our solar system, some of which may be ideal environments for life.
But which candidates exhibit the greatest potential?
Featuring Saturn’s Enceladus and Jupiter’s Europa, this diagram illustrates the moons most likely to be inhabited by extraterrestrial beings.
Experts believe that among the planets most probable to harbor life is Enceladus, the moon of Saturn, which emits water columns from a concealed liquid ocean.
On Earth, CO2 is produced as a byproduct of cellular processes on Europa, the larger moon of Jupiter. Conversely, Callisto potentially harbors a saline ocean beneath its surface, which could serve as a viable habitat for life.
The interaction between water and rock on Ganymede, the largest moon in Jupiter’s solar system, is believed to be crucial for the evolution of life.
Additionally, Triton, the moon of Neptune, is recognized for its geological activity and nitrogen-dominated atmosphere, similar to that of Earth.
Recently, scientists announced the discovery of two additional moons: one encircling Uranus and two encircling Neptune.
Amazingly, NASA estimates that there are ‘thousands’ of additional moons in our solar system that are awaiting discovery.
Dr. Robert Massey, the deputy executive director of the Royal Astronomical Society, concurs with NASA’s assessment that our knowledge of numerous additional moons is extensive.
But they are all likely considerably smaller in diameter, a few hundred to tens of miles, compared to the aforementioned candidates.
Dr. Massey said, “Undiscovered moons are likely orbiting the giant planets Jupiter, Saturn, Uranus, and Neptune.”
However, we can assert with certainty that every major moon in the solar system orbiting other planets has been identified.
But they are all likely considerably smaller in diameter, a few hundred to tens of miles, compared to the aforementioned candidates.
Dr. Massey said, “Undiscovered moons are likely orbiting the giant planets Jupiter, Saturn, Uranus, and Neptune.”
However, we can assert with certainty that every major moon in the solar system orbiting other planets has been identified.
“Currently discovered moons are typically no larger than a few kilometers in diameter; consequently, they are considerably fainter; therefore, larger and more sensitive telescopes are required to detect them.”
Three new moons were discovered by scientists last week, two of which orbit Neptune and one of which orbits Uranus.
Nevertheless, Dr. Massey considers the possibility of extraterrestrial life on any of the three recently discovered moons to be “extremely improbable,” given that they are deemed too small to support an atmosphere and lack subsurface oceans.
An atmosphere is a necessary condition for life to exist, so a lesser moon has a generally lower probability of supporting life.
Professor Martin Hendry of the faculty of physics and astronomy at the University of Glasgow told MailOnline, “If a moon is too small, its gravity is insufficient to retain an atmosphere, so life cannot exist.”
“If the moon is exceedingly diminutive, such that its detection has yet to occur, the tidal forces will almost certainly be sufficient to disintegrate it.”
Certain obscure moons remain imperceptibly feeble, even when observed through the most potent ground-based telescopes.
“Moons and planets merely reflect light from the sun; they do not emit light themselves,” explained Professor Hendry.
A moon that revolves at a considerable distance from a planet that is also situated at a great distance from the sun experiences limited sunlight reflection.
“Because they require such enormous telescopes to be seen, they remained undetected until now.”
The Carnegie Institution for Science astronomer who discovered the new moons orbiting Uranus and Neptune, Dr. Scott S. Sheppard, does not believe that as many as ‘thousands’ of moons remain to be discovered, as NASA estimates.
However, he acknowledged that our current technology is unable to detect them because they are “too small and faint to be seen.”
He explained, “Our current largest telescopes in the world are still limited in how deeply they can efficiently image, which is why there are those size restrictions for moon discovery.”
The dimensions of each of these undiscovered moons range from a few to tens of kilometers, rendering them unsuitable for the existence of life at this time.
However, their surfaces may contain the building blocks of life, as they are believed to be ice-rich in organic matter.
“Studying these moons provides us with a more comprehensive understanding of the processes involved in the formation of the planets, as they are the residual remnants of a once-greater population of objects that were incorporated into the planets.”
His three discoveries increase the total number of known moons for Neptune to sixteen, while Uranus now has twenty-eight. While this is a relatively small number in comparison to the two largest planets in the solar system, it is still considerable.
Jupiter possesses 95 moons, while Saturn boasts an astounding 146 moons, with the latter number consistently increasing.
The likelihood that life exists beyond Earth increases when planets and moons beyond our solar system, also known as “exoplanets” and “exomoons,” are considered.
NASA estimates that there are billions of exoplanets in total, of which a proportion must possess life-sustaining conditions comparable to those on Earth.
