Caroline Smith: Meteorites, Mars and the Road to Mars Sample Return

In this Life Scientific episode, Caroline Smith, the Natural History Museum’s curator of meteorites, shares how tiny space rocks reveal the history of our solar system, the evidence for water on Mars, and the ambitious plans to bring samples from Mars back to Earth. From childhood rock-hunting in the Rocky Mountains to leading European planning for future Mars missions, Smith explains how meteorites unlock scientific clues about life's building blocks and the challenges of space sample containment and study on Earth.

Smith also reflects on her education, a career shaped by resilience, and pivotal moments such as the Perseverance rover’s Mars landing and the prospect of samples someday returning to Earth for analysis, including a remarkable asteroid named in her honor.

Overview

Caroline Smith, a leading meteorite expert, discusses how extraterrestrial rocks illuminate the origins of the solar system and the possible ingredients for life. The conversation covers meteorites on Earth, Mars samples, and the infrastructure needed to study space materials without contaminating Earth or risking biohazards.

“Meteorites can tell us so much. They really are the builders's rubble left over after the solar system formed,” - Caroline Smith

From Rock Collecting to the Natural History Museum

Smith recounts her childhood fascination with rocks in the Rocky Mountains, the impact of family finances and a dramatic moment when her geology career began in earnest thanks to a summer placement at the Natural History Museum. She describes how scanning electron microscopes opened up the chemical world inside meteorites and how Antarctica samples first pulled her into meteorite research under Monica Grady’s mentorship.

“Heat or light, organic molecules, time for that potential life to develop, and water is the critical thing,” - Caroline Smith

Pathways into Space Rock Science

The interview traces Smith’s path through university, a knee injury that redirected her away from a military career towards science, and the pivotal Open University PhD that focused on carbon-rich meteorites. Her work in Scotland and Glasgow led to advances in non-invasive sample analysis, notably the focused ion beam technique that allows detailed study without destroying samples.

Mars, Moon and the Road to Sample Return

Smith explains how her European team built a roadmap for curating samples returned from space, a project that positions Europe alongside NASA in the high-stakes world of Mars sample return. The discussion expands to the practicalities of Mars exploration, including how rover instruments identify scientifically valuable rocks and how samples will be preserved on the journey home.

"Nobody's mentioned the things you need to put in place to be able to look after these samples when they come back from Mars," - Caroline Smith

The Perseverance Era and Public Engagement

The Perseverance mission’s Jezero Crater landing in 2021 is a focal point, with Smith recalling the nerve-wracking few minutes of the landing and the subsequent data-rich investigations that seek biosignatures in Martian rocks. She also describes engaging with the public and the significance of a future return mission for understanding life’s potential past on Mars.

"the rover landed beautifully and yeah, a great sigh of relief,” - Caroline Smith

Legacy, Challenges and the Future

Looking ahead, Smith discusses the political and funding hurdles of sample return, the long timescales involved, and the desire to maximize societal benefit from space science. The episode closes with a nod to her enduring legacy in space science, including an asteroid named Caroline Smith that orbits the Sun between Mars and Jupiter.

"If the mission gets cancelled, I would be gutted," - Caroline Smith