Meteorite reveals clues to origin of life on Earth

Scientists have discovered chemical and molecular fingerprints of the early solar system inside a meteorite that landed in the UK.

Meteorites represent the building blocks of the solar system, providing key insights into the ingredients from which the planets, including our own, are formed. Research using powerful microscopes, conducted by collaborating institutions – including the University of Leeds’ School of Chemical and Process Engineering – has now helped to further that understanding.

A rare group of meteorites, called “carbonaceous meteorites”, are rich in chemical species such as carbon and nitrogen, and likely played a critical role in the delivery of water and organic molecules to the early Earth.

“Winchcombe” is a carbonaceous meteorite that was widely observed to fall in the UK in February 2021, with the first samples collected only around 12 hours after landing. It thereby offers scientists an opportunity to investigate the composition of organic matter in the early solar system without the severe terrestrial alteration effects that usually compromise investigations of meteorites.

A multidisciplinary research team including scientists from the Universities of Leeds, Manchester and York, in collaboration with colleagues at the Natural History Museum in London, Diamond Light Source, the Max Planck Institute for Chemistry in Mainz and led by the University of Münster in Germany, has provided the first in-depth analysis of organic matter within the Winchcombe meteorite at the nanoscale.

“This opens up new avenues of research on these materials in the future using compact, and easily accessible electron microscopy instrumentation.”

Prof Quentin Ramasse, School of Chemical and Process Engineering

They were able to uniquely correlate synchrotron-radiation data with complementary ultra-high resolution spectroscopic information about the nature of the functional chemical groups present in the organic matter, using one of the most powerful electron microscopes in the world at the SuperSTEM Facility in Daresbury, Cheshire.

This allowed the striking in-situ detection of nitrogen-bearing biorelevant molecules, including amino acids and nucleobases that are fundamental components of the larger, complex proteins used in biology.

Pristine molecules

The research shows that Winchcombe still contains pristine extraterrestrial organic molecules that, tantalizingly, might have been crucial to the advent of life on the early Earth.

The findings have been published in the journal Nature Communications.

Quentin Ramasse, Professor of Advanced Electron Microscopy in Leeds’ School of Chemical and Process Engineering, who led the electron microscopy team at the SuperSTEM Laboratory, said: “This work demonstrates that recent electron microscopy instrumentation advances, including monochromated high-energy resolution electron sources and highly sensitive new detector designs, enable the analysis of extraterrestrial organic matter with unprecedented resolution and efficiency.

“This opens up new avenues of research on these materials in the future using compact and easily accessible electron microscopy instrumentation in addition to synchrotron radiation.”

Hugely exciting

Christian Vollmer, Senior Researcher at the University of Münster, who led the research, said: “The identification of bio-relevant molecules such as amino acids and nucleobases in Winchcombe without using any chemical extraction methods is hugely exciting, especially as we were able to highlight spatial variations in their local concentration at the nanoscale.

“This suggests that our approach makes it possible to map functional chemistry in meteorites, even though the sizes of the organic domains are extremely small and the abundances of the chemical compounds very low.”

The researchers used the SuperSTEM Laboratory, the UK National Research Facility for Advanced Electron Microscopy, supported by the Engineering and Physical Research Council (EPSRC). The facility houses some of the most advanced facilities in the world for investigating the atomic structure of matter, and is operated with the support of an academic consortium led by the University of Leeds (also including the Universities of Manchester and York, which were involved in this project, as well as Oxford, Glasgow and Liverpool).

An extremely thin slice of the meteorite, targeting a region of interest rich in carbon-containing chemicals, can be very precisely extracted for further examination, either under an X-ray beam (at Diamond Light Source), or in the electron microscope (at SuperSTEM).

New breakthroughs

Dr Ashley King, Research Fellow at the Natural History Museum, where the Winchcombe meteorite is curated, said: “Our observations demonstrate that Winchcombe represents an important addition to the collection of carbonaceous meteorites, with its pristine composition enabling new breakthroughs in our understanding of organic molecules in the early solar system.”

The electron microscopy facilities were funded by the Engineering and Physical Science Research Council.