The Earth is like a big lab we can use to learn about other worlds
Beneath the surface of every earthquake lies a paradox: destruction that illuminates. Professor Hrvoje Tkalčić of the Australian National University has been entrusted with $3.8 million to pursue one of science's oldest and most patient questions — what lies within planets, and what those interiors reveal about the conditions that make life possible. Using seismic waves as a kind of involuntary planetary X-ray, his work extends from Earth's molten core to the frozen silences of Mars and the Moon, where time has preserved what tectonics long ago erased from our own world.
- A $3.8 million Australian Laureate Fellowship breaks from the norm of short-cycle funding, giving one scientist the rare freedom to pursue deep, slow, uncertain questions about planetary interiors.
- The same earthquakes that devastate human communities send seismic waves through the Earth that act as a continuous CAT scan, revealing the layered composition and thermal structure that sustains life's conditions.
- Mars and the Moon — geologically frozen since the early solar system — offer a window into Earth's own ancient past, before plate tectonics erased the evidence of how rocky planets begin.
- Australia's SPIDER seismometer, bound for the Moon's far side, promises to modernize a dataset last updated in 1977 and map the lunar interior with unprecedented precision.
- Beyond research, Tkalčić frames the fellowship as a cultural signal — that curiosity-driven science, mentorship, and inclusion in STEM are investments a society makes in its own future.
Professor Hrvoje Tkalčić has received one of Australia's most prestigious research grants — a $3.8 million Australian Laureate Fellowship — to pursue questions that most funding cycles consider too slow and too fundamental to support. Based at ANU's Research School of Earth Sciences, his work uses seismology to decode what lies beneath planetary surfaces, and what those hidden interiors tell us about how worlds form and whether they can sustain life.
The method is elegant in principle: when earthquakes rupture, they send waves radiating through the Earth's interior. Measured across global networks of seismometers, those waves reveal the planet's composition, its layering, and the behavior of rock under immense pressure. Tkalčić often describes it as a continuous, involuntary CAT scan — earthquakes as the source, seismometers as the sensors. The same catastrophic events that destroy communities also carry irreplaceable scientific information about the processes that make complex life possible, including plate tectonics, nutrient cycling, and the magnetic field generated by molten iron in Earth's outer core.
But Earth is only one of his laboratories. Mars and the Moon, geologically inert since the early solar system, preserve a record of planetary development that Earth's own restless tectonics have long since overwritten. Studying their interiors is a way of reading Earth's deep past. The Apollo missions left seismometers on the Moon that recorded over 12,000 moonquakes before going silent in 1977 — data that scientists still haven't fully interpreted. A new chapter is opening: Australia is contributing a seismic instrument called SPIDER to a forthcoming lunar mission, destined for the Moon's far side, where it will generate modern, high-resolution data about the lunar interior.
For Tkalčić, the fellowship carries meaning beyond the research itself. It is a platform for mentoring early-career scientists, for outreach to Indigenous communities, and for addressing gender imbalances in STEM. Most of all, he sees it as a statement — that Australia values the kind of science that doesn't promise quick returns, but asks the questions that matter most over the longest timescales.
Professor Hrvoje Tkalčić has just received $3.8 million to ask questions that most funding bodies would call too fundamental, too slow, too uncertain to pay for. The Australian Laureate Fellowship, awarded by the Australian Research Council with substantial backing from ANU, gives him the rare luxury of pursuing curiosity without the usual pressure to show incremental progress every eighteen months.
Tkalčić works at the ANU Research School of Earth Sciences, and his mission is straightforward in concept but vast in scope: understand what lies beneath our feet, and use that knowledge to decode how planets form, evolve, and sustain life. He does this through seismology—the study of how seismic waves travel through planetary interiors. When an earthquake ruptures, it sends waves radiating outward through the Earth like ripples in water. By measuring those waves at stations around the globe, scientists can infer what the Earth is made of, how it's layered, and how it moves. It's a medical analogy he returns to often: the Earth undergoing a continuous, involuntary CAT scan, with earthquakes as the source and seismometers as the sensors.
What makes this work paradoxical is that earthquakes are catastrophic events—they destroy buildings, displace people, kill. Yet their seismic signatures are a gift to science. The waves carry information about the planet's composition, its temperature gradients, the behavior of rock under extreme pressure. And that information matters because the processes that generate earthquakes—plate tectonics, the grinding movement of continental and oceanic plates—appear to be essential for complex life. Plate tectonics drive nutrient cycling and stabilize climate. They also generate the heat that powers Earth's magnetic field, the invisible shield generated by molten iron in the outer core that deflects solar radiation and prevents our atmosphere from being stripped away. Without it, life as we know it would not exist.
But Earth is not Tkalčić's only laboratory. Mars and the Moon are frozen records of planetary history. Mars cooled quickly and never developed plate tectonics; its interior remains largely unchanged since the early solar system. The Moon is even smaller, even more static. By studying their interiors—their rock composition, their layering, their thermal structure—scientists can see what Earth looked like billions of years ago, before plate tectonics reshaped everything. It's a way of reading Earth's own deep past.
The Apollo missions left seismometers on the Moon between 1969 and 1972. Four of them continued transmitting data until 1977, recording more than 12,000 moonquakes. Yet scientists still don't fully understand what causes those quakes or what they reveal about lunar structure. That is about to change. NASA and international partners are planning a new Lunar Environment Monitoring Station, and Australia is contributing a seismic instrument called SPIDER—a small station bound for the Moon's far side. The project, led by Fleet Space Technologies with support from the Australian Space Agency, represents a growing Australian capability in space technology and will provide modern data to map the lunar interior in unprecedented detail.
For Tkalčić, the fellowship is not only about research. It's a platform for mentorship, for raising the next generation of planetary scientists, for outreach to Indigenous communities through ANU's Tjabal Indigenous Higher Education Centre and to address gender disparities in STEM through collaboration with the ANU Gender Institute. He sees the fellowship as a signal to early-career researchers that curiosity-driven science—the kind that doesn't promise immediate applications or commercial returns—is valued at the highest levels of Australian research funding. It's a statement about what the country believes science is for.
Citações Notáveis
The fact that curiosity-driven research is valued at the national level, with significant investment, means that I will be able to pursue fundamental questions without the usual constraints of incremental funding.— Professor Hrvoje Tkalčić
Mars is like an object frozen in time, helping us understand Earth at an early stage of its evolution.— Professor Hrvoje Tkalčić
A Conversa do Hearth Outra perspectiva sobre a história
Why does understanding Mars matter if we're trying to solve problems on Earth?
Because Mars is like Earth frozen in time. It cooled down so fast that its interior never changed the way ours did. By reading Mars, we're reading what Earth looked like four billion years ago. That teaches us about our own deep history.
And the magnetic field—you mentioned it's critical for life. How does seismology help us understand it?
The magnetic field is generated by molten iron moving in the outer core. To understand how that works, we need to know the temperature, composition, and structure of the core itself. Seismic waves travel through it and tell us what's there.
So earthquakes are actually useful?
Paradoxically, yes. They're destructive, but the seismic waves they produce are a window into the planet. We can't drill to the core—it's too deep, too hot. Earthquakes give us data we can't get any other way.
What changes with the new Moon seismometer?
The Apollo instruments were basic by today's standards. SPIDER will be far more sensitive. We'll finally understand what moonquakes are telling us about the lunar interior, and that helps us understand whether the Moon could ever have been habitable, or what conditions are necessary for habitability anywhere.
Is this just about science, or is there something else?
It's about showing young scientists that fundamental questions—the ones without obvious applications—are worth pursuing. That's the real message of the fellowship.