The probability of discovering Earth-like exoplanets harboring liquid water, a requisite for life, is substantially improved, according to a recent study. Even in freezing surface environments, geothermal heat could facilitate the liquification of subterranean water, particularly on planets revolving around prevalent M-dwarfs stars. The research suggests nearly 100 times more planets might possess liquid water than originally estimated, dramatically increasing the possibility of uncovering extraterrestrial life.
The latest findings presented at the Goldschmidt geochemistry conference indicate a significantly increased chance of detecting Earth-like exoplanets with liquid water, a fundamental element for life, compared to prior estimates.
The new examination suggests there are likely numerous additional Earth-like exoplanets with liquid water than previously assumed, substantially augmenting the probability of encountering life. The study posits that even in non-ideal conditions for surface liquid water, many stars could support geological conditions conducive to underground liquid water.
Introducing the research at the Goldschmidt geochemistry conference in Lyon, the lead investigator, Dr. Lujendra Ojha from Rutgers University, New Jersey, USA, stated, “Liquid water is crucial for life, and our findings reveal it can exist in places we hadn’t thoroughly contemplated before, significantly enhancing the prospects of finding environments suitable for potential life development.”
The research team discovered that despite a frozen planetary surface, there are primarily two mechanisms through which sufficient heat can be generated to allow underground water liquification.
Dr. Ojha explained, “We, as Earth’s inhabitants, are currently fortunate to possess the perfect balance of greenhouse gases in our atmosphere for surface water stability. If Earth were to lose its greenhouse gases, the average global surface temperature would be approximately -18 degrees Celsius, leading to the freezing of most surface liquid water. A similar situation occurred a few billion years ago on our planet, with surface liquid water freezing entirely. Yet, this doesn’t imply all water was frozen. For instance, radioactivity-induced heat deep in the Earth can keep water liquid. Even today, we see this in places like Antarctica and the Canadian Arctic, where, despite the freezing temperatures, large subterranean lakes of liquid water exist, sustained by radioactivity-generated heat. There is some evidence suggesting this could be currently happening at Mars’ south pole.”
Dr. Ojha continued, “Some solar system moons, like Europa or Enceladus, contain substantial subterranean liquid water, even with completely frozen surfaces. This is because the gravitational effects of the large planets they orbit, like Saturn and Jupiter, constantly churn their interiors. This effect is akin to our Moon’s impact on tides, but much more potent. This makes the moons of Jupiter and Saturn prime candidates for finding life in our Solar System, and future missions are planned to explore these celestial bodies.”
The research analyzed planets revolving around the most common star type – M-dwarfs. These stars are smaller and much colder than our Sun, making up 70% of the galaxy’s stars, with most rocky and Earth-like exoplanets discovered to date orbiting M-dwarfs.
“Our modeling focused on the feasibility of generating and maintaining liquid water on exoplanets orbiting M-dwarfs using only planet-generated heat. Our findings suggest that considering radioactivity-induced liquid water, a significant percentage of these exoplanets can likely have enough heat to maintain liquid water– far more than we previously thought.
Before this research, it was estimated that roughly 1 in 100 rocky planets around stars would have liquid water. The new model reveals that with the right conditions, this could rise to 1 planet per star. Thus, we are a hundred times more likely to find liquid water than we previously thought. Considering there are around 100 billion stars in the Milky Way Galaxy, this implies promising odds for the existence of life elsewhere in the universe.”
The earliest mission to an “ice world” type moon will be NASA’s Europa Clipper, set to launch in 2024 and arrive at Jupiter’s moon Europa in 2030.
In response to the findings, Prof. Abel Méndez, (Director of the Planetary Habitability Laboratory, University of Puerto Rico at Arecibo), commented, “The potential of oceans concealed beneath ice sheets expands our galaxy’s potential for more habitable worlds. The key challenge is developing methods to detect these habitats using future telescopes.”
Professor Méndez, not involved in this work, provided an independent comment.
The work that this presentation is based on was recently published in the peer-reviewed journal, Nature Communications.
References:
“Liquid water on cold exo-Earths via basal melting of ice sheets” by Lujendra Ojha, Bryce Troncone, Jacob Buffo, Baptiste Journaux, and George McDonald, 6 December 2022, Nature Communications. DOI: 10.1038/s41467-022-35187-4
“Habitability and sub glacial liquid water on planets of M-dwarf stars” by Amri Wandel, 14 April 2023, Nature Communications. DOI: 10.1038/s41467-023-37487-9
Additional commentary can be found at https://www.nature.com/articles/s41467-023-37487-9
The Goldschmidt Conference is the leading global geochemistry conference, a joint congress of the European Association of Geochemistry and the Geochemical Society (US). It takes place in Lyon, France, from 9-14 July, with nearly 5000 delegates anticipated to attend.
Table of Contents
Frequently Asked Questions (FAQs) about Extraterrestrial Life Discovery
What is the main finding of the recent study discussed in the text?
The main finding is that the chances of discovering Earth-like exoplanets with liquid water, a prerequisite for life, have been significantly increased – nearly 100 times more than previously believed.
Who presented the research?
Dr. Lujendra Ojha from Rutgers University, New Jersey, USA, presented the research at the Goldschmidt geochemistry conference in Lyon.
How can water liquify underground in freezing surface conditions?
There are primarily two ways that sufficient heat can be generated to allow underground water liquification: through the heat from radioactivity deep within the planet and through the gravitational effects of the large planets some moons orbit.
What is the significance of M-dwarfs stars in the research?
M-dwarfs are the most common type of stars, making up 70% of the galaxy’s stars. Most rocky and Earth-like exoplanets discovered to date orbit M-dwarfs. These planets are considered in the research as potential places for generating and maintaining liquid water.
What is the earliest mission to an “ice world” type moon?
The earliest mission to an “ice world” type moon will be NASA’s Europa Clipper, set to launch in 2024 and arrive at Jupiter’s moon Europa in 2030.
How does this research affect the search for extraterrestrial life?
The research suggests that there may be a hundred times more planets with liquid water than previously thought. Considering the importance of water for life, this implies promising odds for the existence of life elsewhere in the universe.
More about Extraterrestrial Life Discovery
- NASA’s Europa Clipper Mission
- Goldschmidt Conference
- Planetary Habitability Laboratory, University of Puerto Rico at Arecibo
- Nature Communications: “Liquid water on cold exo-Earths via basal melting of ice sheets”
- Nature Communications: “Habitability and sub glacial liquid water on planets of M-dwarf stars”
6 comments
This is why i love science… its always showing us new possibilities. just imagine, there could be so much life out there!
told ya all, aliens are real!! This just proves it. Now its just a matter of time until we find them, you’ll see!
Impressive! These M-dwarf stars might be colder, but they hold so much potential. The Universe keeps surprising us, eh?
so basically… we’re saying there’s a chance! Life could be anywhere, even in the most unexpected places…exciting times ahead!
Science never stops evolving, does it? One day we’re alone in the universe, the next day there’s a good chance we’re not. Beautiful.
Ojha’s research is fascinating! Always wondered about other planets, even the cold ones. but never thought about underground water. Amazing!