Have you ever stopped to wonder what makes your smartphone work or how the magnets in your headphones produce sound? Behind the sleek design and cutting-edge technology of our modern devices lies an often-overlooked ingredient: rare earth elements (REEs). These metals, though hidden from sight, are essential for nearly every aspect of contemporary life.
But as our hunger for technology and advancement grows, so does the demand for REEs, which are currently used as means of leverage in larger geopolitical plays. This naturally brings the question of: Could space provide an alternative to securing these vital resources? Let’s explore where rare earths exist beyond our home planet and what that could mean for the future of tapping into resources beyond terrestrial grounds.
What Are Rare Earth Elements? A Brief Overview
Rare earth elements, known as REEs for short, are a group of 17 metallic elements that include the 15 lanthanides on the periodic table (lanthanum to lutetium), plus scandium and yttrium. Despite what their name might imply, REEs are not necessarily rare, with cerium (Ce), for example, being the 25th most abundant element on Earth.
Viable mineral deposits of these elements can actually be found across the globe. The real challenge does not lie in their availability but in their complexity. Extracting REEs is a delicate process, made difficult by intricate mineral structures that complicate both the processing and metallurgy of these elements.
REEs are crucial for modern technology, serving as raw materials in everything from smartphones, lightbulbs, and USB drives to electric vehicles, medical imaging devices, and military equipment. Their unique magnetic, luminescent, and electrochemical properties make them irreplaceable in advanced applications.
Where Are Rare Earth Elements Found on Earth?
Baiyun Ebo, China
Most REEs are mined from deposits generally consisting of complex minerals such as bastnäsite (REECO3 (F, OH)), monazite ((REE, Th, Ca, Sr) (P ,Si, S) O4), and xenotime ((REE, Zr) (P, Si) O4), among others, which are primarily located in China, the United States, Australia, and some African nations. The largest accumulation of REEs is found in the Bayan Obo deposit in China.
According to the 2017 USGS Mineral Commodity Summary, Earth’s reserves of rare earth elements (REEs) amounted to 140 million tonnes, with nearly half of these resources located in China (55 million tonnes), followed by the United States (13 million tonnes).
Due to this, the Chinese government controls the majority of global rare earth production, at times causing international supply concerns. This is why the country has scrapped its export quotas following pressure from the WTO. Given their growing demand and threatened supply lines on Earth, the idea of mining rare earth elements in space has gained traction.
What Are the 17 Rare Earth Elements Used for?
Rare earth elements play a crucial role in a variety of industries, enabling the development of advanced technologies that shape our modern world. Their unique properties make them essential for numerous applications, including:
- Electronics: Used in smartphones, tablets, laptops, televisions, computer processors, and hard drives to enhance performance and efficiency.
- Renewable Energy: Key materials in wind turbines, solar panels, rechargeable batteries, electric grid storage solutions, and hydrogen fuel cells.
- Medical Technology: Found in MRI machines, X-ray devices, surgical lasers, radiation therapy equipment, and biomedical imaging systems.
- Defense Systems: Utilized in precision-guided missiles, advanced radar systems, night vision goggles, jet engines, and submarine detection technologies.
- Automotive Industry: Crucial for electric vehicle motors, catalytic converters, hybrid vehicle batteries, fuel cells, and lightweight structural components.
- Communication: Essential for fiber optics, satellite systems, GPS devices, high-frequency telecommunications, and secure military communications.
Without these elements, many of the technological advancements we take for granted would not be possible. As demand continues to rise, the exploration of deposits in new jurisdictions becomes increasingly important. There have been some ideas that space could present another source for these elements, but is this really true?
Rare Earth Elements in Space: A New Frontier to Explore
To meet the strong demand for green and digital technologies we use in daily life, the production of rare earth elements (REEs) has increased significantly, combined with increasing geopolitical instabilities in a de-globalizing world. Given that Earth’s material and energy resources are ultimately finite, our continued dependence on rare earth elements inevitably calls for the exploration and utilization of resources beyond our planet.
Where Could Rare Earth Elements Be Found Beyond Earth?
The search for extraterrestrial materials containing REEs has led scientists to focus on asteroids, the Earth’s Moon, and Mars. These celestial bodies offer unique geological compositions that could potentially house valuable deposits of rare earth elements.
The Moon’s surface, covered in lunar regolith, could contain trace amounts of REEs, while asteroids, especially those of the carbonaceous chondrite variety, are believed to have promising concentrations of these essential materials. Mars, with its more complex geological history, also presents an exciting opportunity to explore. By studying these locations, scientists aim to uncover new ways of sourcing these resources beyond Earth.
Asteroids
Asteroids are compelling targets for in situ REE resource extraction because they represent primordial remnants of the solar system with relatively unaltered metal and mineral compositions. Many near‐Earth asteroids, for instance, particularly carbonaceous chondrites, are expected to contain a mix of metals and silicate phases, including REE‐bearing minerals.
The most promising targets, however, appear to be M-type asteroids. Although the REE concentrations in these asteroids are relatively low, typically lower than most terrestrial deposits, mining operations aimed at extracting iron, nickel, gold, and platinum group elements (PGEs) could yield REEs as a valuable byproduct.
Furthermore, the sheer number and compositional diversity of asteroids offer opportunities to selectively target bodies that may be enriched in REEs, complementing terrestrial and lunar sources.
The Moon
In the quest for REE resources beyond our planet, the Earth’s Moon emerges as another focal point for future mining efforts. Some parts of our closest neighbor have a good potential for REE extraction due to their unique geology. Studies of lunar rocks brought back by Apollo missions suggest the presence of basalt-rich deposits that may house REEs, found in specific areas called KREEP terrains, which are strongly enriched in REEs, potassium, and phosphorous.
These types of basalts formed from the leftover melt of the lunar magma ocean and were later brought to the surface and exposed by volcanic activity during the early stages of the Moon’s geological history, where trace minerals like apatite and merrillite can host valuable REEs.
Beyond resources, the Moon’s close proximity and low gravity could also significantly reduce transportation and operational costs compared to more distant celestial bodies. With growing global demand, lunar mining could help alleviate terrestrial supply chain pressures and provide a strategic, sustainable alternative to Earth‐bound resources.
Mars
The Red Planet, too, shows promise. Certain regions on Mars, where anorthosite and felsic crustal materials have been detected, could serve as valuable sources of essential incompatible elements and rare Earth materials. The presence of basalt and the planet’s intense volcanic history suggests the potential for REE deposits, though this still remains largely speculative due to limited sample return missions.
A biological experiment conducted aboard the International Space Station back in 2020 demonstrated that certain bacteria can effectively extract rare earth elements from basalt rock in microgravity and simulated Martian gravity conditions.
This finding suggests that biomining could be a viable method for obtaining essential materials during future space missions to the Moon and Mars and highlights the importance of innovative ideas for using microorganisms to support extraterrestrial resource acquisition, which is crucial for the sustainability of long-term space exploration.
An Attempt in Identifying REEs on the Red Planet
A recent study by researchers at Washington University has also taken a significant step in addressing this challenge by assessing the ability of hypersensitive scanners aboard NASA’s Perseverance rover (an X-ray spectrometer called PIXL, Planetary Instrument for X-ray Lithochemistry) to detect and quantify REEs within Martian soil. Since landing in 2021, Perseverance has been methodically analyzing rocky terrain, collecting crucial data that could help us determine the availability of these critical materials.
Although the research team determined that Perseverance’s instrument might not be sensitive enough to detect certain rare earth elements, such as cerium (a rare earth metal), at anticipated Martian concentrations, their findings emphasize an important conclusion: for a complete and accurate analysis of these extraterrestrial materials, returning samples to Earth is essential. Only through direct laboratory examination can scientists unlock the full scope of Mars’s geological composition and assess the feasibility of utilizing its resources for future exploration.
How Could Rare Earth Elements Be Extracted in Space?
Extracting REEs from extraterrestrial materials still presents a formidable challenge, but various technologies are in the experimental phase. Researchers are actively testing innovative methods that could one day enable space mining of REEs and other elements.
Studies conducted at NASA Kennedy Space Center and other institutions aim to develop and refine techniques and in-situ resource utilization (ISRU) strategies for efficient resource extraction in space.
Microbial Bioleaching
This method uses specialized microorganisms to solubilize elements from materials such ss basaltic rock. In experiments like ESA’s BioRock aboard the International Space Station, microbes (e.g., Sphingomonas desiccabilis) were shown to enhance the extraction of REEs under microgravity, Mars, and Earth gravity conditions.
By metabolizing the minerals, these organisms effectively “leach” the REEs into a liquid phase that can later be recovered. This low-energy process offers promise for in-situ resource utilization (ISRU) on the Moon or asteroids.
Chemical Leaching and In-Situ Processing
Chemical extraction methods involve using acids or other reagents to dissolve REE-bearing minerals. In a space setting, these processes must be carefully engineered to work in a vacuum and under microgravity, often by integrating compact reactors that can operate autonomously. Such methods could complement biomining by allowing further purification and concentration of the leached elements.
Mechanical and Physical Separation Techniques
Traditional mining techniques, such as crushing, milling, and flotation, are being adapted for space environments. Autonomous Systems and Robotics (ASR) may use mechanical agitation, vibration, or even centrifugal forces to segregate REE-rich fractions from the bulk regolith. These methods might be combined with sensor-driven feedback systems to optimize the separation process in low-gravity conditions.
Thermal and Optical Mining Methods
Some companies are exploring novel approaches like optical mining, which uses concentrated sunlight to thermally fracture or sublimate material. This process could help liberate REEs from the host rock by weakening the mineral matrix, making subsequent extraction easier. Given the abundance of solar energy in space, these thermal methods could offer an energy-efficient and affordable solution.
Integrated Autonomous Systems and 3D-Printed Infrastructure
A long-term vision involves the deployment of fully autonomous mining plants that are constructed in space using additive manufacturing. Such systems would integrate robotic excavation, chemical or biological processing, and refined material handling – all built from locally sourced regolith. These ISRU frameworks aim to reduce Earth-dependence by turning raw extraterrestrial materials into components for spacecraft, electronics, and habitat infrastructure.
For example, NASA has partnered with ICON, a Texas-based construction technology firm, to explore and develop a construction system designed for use in space, aiming to facilitate upcoming missions to the Moon and Mars. ICON has already made strides in 3D printing homes and facilities on Earth and actively took part in NASA’s 3D Printed Habitat Challenge, showcasing building techniques and technologies that could be modified for extraterrestrial use.
What Could Space-Mined REEs Be Used for?
The potential applications of space-mined REEs extend far beyond compensating for our daily needs here on Earth. Some of the most exciting possibilities of using these resources space in the future include a wide range of potential applications, such as:
- Supporting space colonies: REEs could be used in the production of solar panels, batteries, and electronic components for lunar or Martian habitats.
- Advanced propulsion systems: Certain REEs are critical for ion propulsion technology, which could enable faster and more efficient space travel.
- Manufacturing in space: Space-based 3D printing and in-situ manufacturing would benefit from a steady supply of REEs, reducing the need to launch materials from Earth.
How Much REEs Would We Need?
Unlike base metals such as iron or copper, which are required in vast quantities (hundreds of thousands to millions of tons) to support large-scale industrial operations and Mars or lunar development, the demand for rare earth elements (REEs) is relatively modest compared.
Preliminary estimates suggest that for the initial decades of Mars colonization, for example, only a few hundred tons of REEs per year would be necessary. While transporting this amount from Earth would require several rocket launches (a costly endeavor), it remains far more cost-effective and logistically simpler than establishing and operating the complex and energy-intensive infrastructure needed to mine and process REEs in situ on Mars or the Moon.
Thus, to ensure the long-term sustainability and self-sufficiency of off-world colonies, we must continue to invest in research and development to make in-situ REE extraction more affordable.
Challenges & Considerations
Innovations in space exploration technology have the potential to broaden our currently “closed” planetary economy system by incorporating extraterrestrial resources. However, despite the promising prospects, there are still significant hurdles to overcome in space mining. These include technical feasibility, as extracting REEs in extraterrestrial environments is a complex task requiring innovative technologies.
Space mining must also be cost-competitive with terrestrial extraction, factoring in the expenses of transportation, equipment, and infrastructure for economic viability. Achieving breakthroughs in automated mining, processing, and recovery technologies will be crucial in reducing our reliance on Earth-sourced materials over time. There’s still a lot to be figured out, but we’re definitely getting there.
The Search for Rare Earth Elements in Space Continues
Recent space experiments have provided valuable insights into the possibilities of space-based REE mining, and research is progressing rapidly, driven by both governmental and private sector initiatives. For instance, NASA’s Polar Resources Ice Mining Experiment-1 (PRIME-1), scheduled for launch in 2025, aims to gather data that will help scientists understand in-situ resources on the Moon, including resource location mapping.
Similarly, private companies like AstroForge are developing technologies to mine valuable metals from asteroids, reflecting the growing commercial interest in space resource extraction. As our dependence on REEs grows, space is destined to become the next logical frontier for securing these critical resources in the future.
Whether through lunar mining, asteroid retrieval missions, or Martian exploration, the race to tap into rare earth elements beyond Earth has begun. The future of space mining is brimming with possibilities, and the quest for REEs will definitely play an important role in shaping humanity’s presence beyond our home planet.