Fast, computer-assisted detection of dust and debris impact craters on Stardust interstellar foils

Bradley T. De Gregorio, Jessica Opsahl-Ong, Lysa Chizmadia, Todd H. Brintlinger, Andrew J. Westphal, Rhonda M. Stroud

Research output: Contribution to journalArticlepeer-review

Abstract

The NASA Stardust Interstellar Dust collection provides our current best sample set for direct laboratory analysis of dust grains from the contemporary interstellar dust stream. While a handful of likely interstellar dust grains were identified within the silica aerogel collection media, interstellar dust also impacted Al foils covering the collector frame. Locating these rare impacts requires labor-intensive collection and examination of tens of thousands of high-resolution SEM images. Here, we implement a Python-based algorithm to dramatically reduce the human time investment needed to locate impact craters. The algorithm employs a circular Hough transform to identify circular features in the foil images, followed by several tests to detect characteristic morphological features of impact craters—a dark center and a bright rim, with inclusion of multi-core processing capabilities to significantly increase processing speed. For most data sets, the code produced a pool of potential crater candidates in 1–5% of the input images, producing a more manageable subset of images for a human expert to review. We used this code to locate 31 impact craters across 12 Stardust interstellar foils, 25 of which were located on three adjacent foils, I1008W,1, I1009N,1, and I1020W,1. Many impacts on these foils formed shallow, oblique craters, with residue compositions consistent with solar cell glass and orientations consistent with debris ejected from the spacecraft solar cells. The code can be integrated into future searches for Stardust interstellar grain impacts and can be implemented as a general utility for dust impact studies on spacecraft materials.

Original languageEnglish (US)
Pages (from-to)944-959
Number of pages16
JournalMeteoritics and Planetary Science
Volume56
Issue number5
DOIs
StatePublished - May 2021
Externally publishedYes

Bibliographical note

Funding Information:
This work was funded by the NASA Laboratory Analysis of Return Samples Program grant numbers 80HQTR20T0050 and NNH17AE44I. Use of both FIB‐SEM instruments at the U.S. Naval Research Laboratory was supported by the NRL Nanoscience Institute. We also thank the two reviewers of this manuscript, who gave detailed and thoughtful criticism of this work.

Publisher Copyright:
© 2021 The Meteoritical Society (MET). This article has been contributed to by US Government employees and their work is in the public domain in the USA.

Fingerprint

Dive into the research topics of 'Fast, computer-assisted detection of dust and debris impact craters on Stardust interstellar foils'. Together they form a unique fingerprint.

Cite this