Mercury, the smallest planet in our solar system, remains one of the most enigmatic worlds. Its extreme environment, puzzling magnetic field, and unique geology make it a fascinating subject for scientists.
According to Anne Pommier, an experimental geophysicist at Carnegie Science’s Earth and Planets Laboratory (EPL), “We still don’t fully understand how Mercury got to be the way it is.” Decades of research, new lab experiments, and upcoming missions aim to shed light on this mystery.
One of the biggest questions surrounding Mercury is its metal-rich composition. Its core makes up 60% of the planet’s volume, unlike Earth’s 15%. Scientists debate whether Mercury formed from metal-rich building blocks or if early collisions stripped away much of its rocky mantle. Pommier notes that more data and experiments are needed to determine the correct hypothesis.
A new mission, BepiColombo, will launch in 2025 and explore Mercury’s magnetic field, chemistry, and electrical conductivity. To interpret this data, scientists require a deeper understanding of how Mercury-like rocks behave under similar conditions. Pommier’s team creates analog materials that replicate Mercury’s oxygen-poor geochemistry, allowing them to study the planet’s properties.
Researchers have also synthesized Mercury-like glasses, analyzing them using high-resolution tools like Raman spectroscopy and electron microscopy. The results revealed a striking difference in the physical properties of Mercury’s ancient lavas compared to those on Earth.
The magnetic field is another area of ongoing research. Scientists have run thousands of models simulating Mercury’s core evolution over billions of years, finding that only a narrow range of scenarios reproduce both the observed field and the magnetic signature detected in crustal rocks formed 3.8 billion years ago.
Basic research has far-reaching applications beyond planetary science, leading to discoveries that improve our understanding of energy, materials science, and electronics. As Pommier emphasizes, fundamental science ultimately underpins technological advancements that shape our lives.
With BepiColombo on the horizon, scientists are gearing up for a new wave of discoveries. Experiments like Pommier’s will be essential in interpreting what the mission finds, creating a feedback loop between lab and space. As one scientist notes, Mercury serves as a crucial benchmark, providing insights into how rocky planets form and evolve. The work is just beginning, and experimental geophysics holds the key to unlocking Mercury’s secrets.
Source: https://phys.org/news/2025-06-mercury-experimental-geophysics-revealing-strangest.html