The Chemical analysis of impact sites will help in determining the impacting particulate origin.  Impacts are classified as being caused by either space debris (man-made) or micrometeoroids (natural), or unknown in the case where data was inconclusive (the majority of cases).

The chemical analysis schedule consists of a series of analyses to be performed at the Venture Business Laboratory of the Tokyo Institute of Technology.  A JEOL JSM 5310LV microscope with Energy-Dispersive X-Ray system (EDX) is used which requires no pre-analysis conducting coating to be applied to the sample, thus minimising additional contamination.
 

The combined results of the chemical analysis will be published in an SFU Chemical Analysis Portfolio. The following tables list the SSM impacts analysed and the results obtained so far. Click on the image to retrieve either an SEM Image of the impact site or the EDX Spectra for that site.
 

PLU-1 SSM ID Particle Origin SEM Image EDX Spectra P14   K12   T4   H10   V13   Z11   F2   M10B   M10C   S10   L9   W11   N4   P11   U11   K9   S14   Q1   C5   X6   W7   A5   W14   015   B6   O10   U10   B2   G12   V11   D14   J1   Y9   Q13   B11   P10   N13   C4   P5   L12   A10   E7B   O1   E7A   U15A   I15A   H6   K4

PLU-4 SSM ID Particle Origin SEM Image EDX Spectra M15B   < G5   < J7   < B12   < J1B   < I4   < R7   < M8   < R14   < J14   < K9   V6   H5   W13   X6   B11A   N14   B2   P2   M15   I7   M12B   J2   Q2   S6   P8A   Z1   L12   D9   L2   X3   E10   M12A   K1   L3   V3   I10   P8B   Y13   R13   U6   K10   N13   O1   AB7B   A9   AA10

PLU-2 MLI

The spectra for 56 impacts on the MLI of PLU-2 are included below.  More data will be added as the chemical analysis progresses.

For each impact site, the investigations strategy was as follows:

    1) peel off the top MLI layer and mount it on the special SEM sample holder, face up.
    2) repeat for the last MLI layer, i.e. the one which finally stopped the impactor, mounting it face up also.
    3) discard all intervening layers, as well as those layers not perforated by the target

The reasoning behind this strategy was simply that we presumed that the top and bottom layers would be the ones most likely to have retained impactor residues, particularly the bottom layer, for the impactor would by that stage have slowed down to the extent that complete vaporisation was unlikely (however a large amount of MLI material from the upper layers will probably have been mixed in with the projectile).

Before searching for impactor residues we took a low-magnification image of the impact site (one for the top and bottom layers respectively) and the surrounding area using the SEM, on which we marked the precise areas that we subjected to EDX analysis.  In general it was quite easy to distinguish between contamination, and it was found that a number of sites were severely contaminated during sample preparation.

PLU-2 MLI consisted of seven separate sheets, six of which were found to contain impacts.  Below is a table summarising our findings, below which are links to download files containing the image overviews of the impacts sites with ...... We decided not to provide links to individual impact sites.
 

PLU-2 MLI #1 ID # Particle Origin SEM Images EDX Spectra 1 * 2 3 4 5 6 7 8 9 10 * 11 * 12 * 13 * 14 * 15 * 16 * 17 * 18 * 19 * 20 * 21 * 22 * 23 * 24 25 * 26 *

Download all the PLU-2 MLI No. 1 SEM Images.

Download all the PLU-2 MLI No. 2 SEM Images.

Download all the PLU-2 MLI No. 3 SEM Images.

Download all the PLU-2 MLI No. 5 SEM Images.

Download all the PLU-2 MLI No. 6 SEM Images.

Download all the PLU-2 MLI No. 7 SEM Images.

For further information please contact seed@jaxa.jp .