Application Note

The building blocks of our solar system
Studying the Winchcombe meteorite

Authors: Dr. Rich Taylor		 Carl Zeiss Microscopy, Cambourne, UK		Dr. Martin Suttle		 Open University, Milton Keynes, UKDate:		June 2023

Introduction
Meteorites are among the most exciting rocks that we canto be safely collected for the various research teams that wouldfind on Earth because they were formed in outer space andthen be involved in studying it. The UKFAll camera network washave fallen to our planet’s surface by chance. Meteorites arealso able to track the rock back to its point of origin, on thethe ancient building blocks of our planets dating back toouter edge of the asteroid belt between Mars and Jupiter.

4.6 billion years ago and studying them gives us a glimpse
into how our solar system formed and evolved.

The Winchcombe meteorite is one of the most exceptional
meteorites to be studied due to how fast it was able to be

On the 28th of February 2021 a very special event happened:collected. Its limited exposure to Earth’s atmospheric conditions

a meteorite fell from the sky over the UK and fragments

makes it one of the most spectacularly preserved extra-of it landed in and around the Gloucestershire village ofterrestrial samples, comparable to the sample return missions

Winchcombe. Its fiery trail was captured by the nationalthat collect rocks using satellites from outer space itself. Its

network of cameras that form the UK Fireball Alliance (UKFAll),

pristine nature means everything from organic material toenabling its final location to be narrowed down with great

magnetic properties can be analyzed to understand how planets

accuracy. It took less than a day for over 500g of materialare formed.

ab350 µm

350 µmcd350 µm

350 µmFigure 1 a) SEM BSE image shows the complex, predominantly fine-grained sample of the Winchcombe meteorite; b-d) quantitative EDS maps of Fe, Mg and S(overlaid on BSE) allow instant visualization of difficult mineralogy even in complex samples. Even with no previous mineral library, all variations can be taken into
account for further assessment, e.g. with automated mineralogy.

2ab

40 µm

40 µm

Figure 2 a-b) Close-up quantitative EDS maps (Fe and Mg) of an olivine aggregate chondrule seen within the sample in Figure 1.
Pure Fe-metal inclusions can be seen within the most pristine parts of the forsteritic olivine.

ZEISS is fortunate to be involved with two of the Winchcombe

FE-SEM EDS analysis

science teams tasked with understanding the fundamental

Quantitative EDS mapping of the surface of the entire ~15 mm2structure and mineralogy of this fantastic rock. For thissample allows instant insight into the variation that can be seen

research, the ZEISS Mineralogic software suite was used towithin the sample. Comparing the greyscale backscatteredperform quantitative energy dispersive spectroscopy (EDS)

electron (BSE) image (Figure 1a) with quantitative element

mapping in conjunction with automated mineralogy, alongsideheatmaps (Figure 1b-d) makes it possible to instantly determine

the latest µCT scanning software processing techniques. By

the numbers of different materials that make up the broad

understanding the Winchcombe sample in both 2D and 3D withmineralogy of the sample. Features are visible across multiple

complementary approaches, we can gain the greatestorders of magnitude from the silicate chondrules that remain

insight into the history of this complex sample.

unaltered and up to 500 μm in size (Figure 2a-b), down tosubmicron clay-like minerals formed from fluid alteration.

The sample consists of a single fragment mounted in a 25 mm
diameter epoxy disk with a polished surface of approximately

Context µCT analysis

4x5 mm. 2D analysis of the polished surface was performed

Carbonaceous chondrites provide many challenges forusing a ZEISS Sigma 300 field emission scanning electron

traditional μCT imaging. The main goal of the project was

microscope (FE-SEM) equipped with two Oxford Instruments

to assess the nature of the clasts within the breccia in terms

Ultimax 65 mm2 EDS detectors for chemical analysis. 3Dof size, shape, and preferred orientation, along with thedata were collected with a ZEISS Context µCT system using

clast-to-matrix ratio. These data inform planetary scientists

a standard source and detector setup, combined with deep

about the processes that occurred on the asteroid bodylearning image enhancement and quantitative analysis.

from which the meteorite originated. As the matrix itself isformed from the same material as the clasts, with only aUsing combined structural and chemical analysis, theminor density difference, standard μCT imaging makes

Winchcombe sample has been classified as a rare CM2

it difficult to discern the differences.

carbonaceous chondrite. It can be described as a monomict
breccia, meaning that it is composed of a single original rock

However, the latest developments in contrast-to-noise

type, but that rock has been blasted apart by collisions in space

image enhancement using the deep learning technology ofand larger fragments are then stuck back together by fine-ZEISS DeepRecon Pro allows these subtle density variations tograined material (clasts within a matrix). The sample has also

be used for image analysis and segmentation. A total of 44

been altered by fluids that formed part of the rock mass itself,

clasts were able to be clearly identified within the matrix

changing the structure and composition of many of the original(Figure 3a-b). The lack of deformation of the clasts themselves,minerals. The result is a very complex sample that requires

or fabric within the sample, enabled an assessment of themany techniques to understand its history.

processes happening on the original asteroid body within
our solar system.

3a1 mmb1 mm

Figure 3 a) Segmentation following deep learning-assisted reconstruction allowed clasts (green) and matrix (pale blue) to be separated. Sulfide and oxide minerals

Image enhancement, reconstruction, and segmentation using

Summary

the DeepRecon Pro part of the ZEISS Advanced Reconstruction

Obtaining quantitative data across multiple microscopy

Toolbox and ZEISS Mineralogic 3D mean this complex sample

techniques is the best way to generate the information

can be analyzed for all the clast information the sciencethat most accurately describes our sample. The use ofteam set out to generate. The quantitative approach ofquantitative EDS means that complex samples can be

Mineralogic 3D also means that the same consistent values

interrogated for bulk and mineral compositions straightfor matrix and clast can be applied to multiple fragmentsfrom SEM, streamlining the process of generating newof the sample, and subsequently used to compare withmineral libraries for automated mineralogy. By using

other meteorite samples.

the new quantitative approach for lab-based μCT,
the maximum amount of information can be gained
from precious meteorites and space mission samples
before any destructive techniques are used.

Carl Zeiss Microscopy GmbH07745 Jena, Germany
microscopy@zeiss.com
www.zeiss.com/microscopy

EN_44_013_099 | CZ 06-2023 | Design, scope of delivery and technical progress subject to change without notice. | © Carl Zeiss Microscopy GmbHcollisional processes happening on the initial parental body from which the Winchcombe meteorite originated.

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(orange-red) were also characterized using 3D automated mineralogy with ZEISS Mineralogic 3D. b) Size, distribution, and shape analysis of clasts give insights into