SomBench: Benchmark Dataset for Advancing Machine Learning in Lunar Science
Authors: Himanshu Patil, Gabby Nyirjesy, Rachel A. Slank, Vishal Gaur, Daniela Szwarcman, Paolo Fraccaro, Nikolaos Dionelis, Michael K. Barker, +14 more
Organizations: The University of Alabama in Huntsville, Huntsville, AL, USA · IBM Research, Yorktown Heights, NY, USA · Science and Technology Institute, Universities Space Research Association (USRA), Huntsville, AL, USA · NASA Goddard Space Flight Center, Greenbelt, MD, USA · SETI Institute, Mountain View, CA, USA · NASA Ames Research Center, Moffett Field, CA, USA · University of Maryland, Baltimore County (UMBC), Baltimore, MD, USA · Howard University, Washington DC, USA · NASA Headquarters, Washington, DC, USA · NASA Marshall Space Flight Center, Huntsville, AL, USA
Lunar orbital missions, such as Lunar Reconnaissance Orbiter, Kaguya/SELENE, Gravity Recovery and Interior Laboratory, and Lunar Prospector, among others, provide rich multi-instrument observations, but their heterogeneity in sampling, projection, and conventions limits reproducible machine learning (ML). We introduce SomBench, a unified, spatially-aligned, ML-ready lunar dataset aggregating 30+ co-registered layers from ten instruments across four missions, spanning 1 meter to 20 kilometer/pixel and covering 82 degree latitude in 90 Lunar Transverse Mercator zones with two polar stereographic caps. An image-anchored tiling pipeline yields pretraining-ready multimodal tile views with leakage-safe splits, distributed as netCDF with Parquet catalogs. An application benchmark suite spans impact processes, volcanic history, and polar volatiles. Baseline experiments with ResNet-50 and SwinV2-B models confirm that each benchmark task is learnable from the released inputs, establishing reference points for future model development.
Figures & tables
Instrument
Mission
Resolution
Bands / Products
Data Type
LROC NAC
LRO
∼1 m
Panchromatic ( 400−760 nm)
Individual images, stereo DTMs + related topographic maps
Global stereo DTM mosaic + related topographic maps
Table 1: Missions, instruments, and data products included in SomBench.
Region ID
NAC PHO Site Name
Number of images
E009S3481
Apollo 15 SIVB Impact
83
E010N0230
Apollo 11
99
E011N1499
Highlands
88
E018N3346
Mare Impact Melt
54
E041N1229
King Crater Ejecta
32
E074N3010
Reiner Gamma
20
Table 2: Co-registered NAC Photometry (PHO) locations and number of images.
Figure 1: The distribution of NAC, NAC Feature Specific, NAC IMP, NAC PHO, NAC DTMs and DTM Orthomosaic images over the lunar surface in the SomBench dataset.
Figure 2: Image presents the distribution of WAC, WAC Feature Specific and WAC PHO Site images used in the SomBench Dataset.
Table 3: Summary of lunar global static map products. A dash indicates a product released for only one of the two regions; polar latitude ranges apply at both poles.
Figure 3: Tile extraction pipeline for the image-anchored low-resolution and high-resolution tracks.
Figure 4: Example of low-resolution non-polar ( top ) and polar ( bottom ) samples, displaying all modalities side by side. Plots include the first channel of each modality at 51.2 x 51.2 km resolution, or 512 x 512 WAC visible pixels. Certain modalities, such as PSR and ALBEDO , only exist at the poles and are thus missing from the non-polar sample. Similarly, other modalities, such as TIO2 and ROCK_ABUNDANCE , do not exist at the poles.
Figure 5: Example of high-resolution non-polar ( top ) and polar ( bottom ) samples, displaying all modalities side by side. Plots include the first channel of each modality tile at 512 x 512 m resolution, or 512 x 512 NAC pixels. Certain modalities, such as PSR and ALBEDO only exist at the poles and are therefore missing from the non-polar sample. Similarly, other modalities, such as TIO2 and ROCK_ABUNDANCE do not exist at the poles.
Component
Low-Resolution Track
High-Resolution Track
Optical Anchor
WAC VIS (100 m/px)
NAC (1 m/px)
Tile Resolution
51.2 km × 51.2 km
512 m × 512 m
Tile Size (pixels)
512 × 512
512 × 512
Rejection stride
120
120
Pass 1 Extracts
VIS, UV, DTM (60m)
NAC only
Pass 2 Extracts
Static maps
NAC-derived DTMs + Static maps
Table 4: Comparison of low-resolution and high-resolution track characteristics.
Modality
Dataset key
Native Resolution (m)
Low-resolution count
Low-resolution avg. null (%)
Low-resolution snapped resolution (m)
High-resolution count
High-resolution avg. null (%)
High-resolution snapped resolution (m)
NAC Panchromatic
NAC
1.0
–
–
–
1,000,113
0.14%
1.0
WAC VIS ( 415nm689nm )
WAC_VIS
100.0
963,609
0.24%
100.0
–
–
–
WAC UV ( 321nm360nm )
WAC_UV
500.0
963,609
0.26%
501.96
–
–
–
Topography (SLDEM2015)
DTM_60M (high-res) DTM (low-res)
60.0
963,609
0.00%
60.02
1,000,113
0.00%
56.89
NAC-stereo DTM
DTM_3M
3.0
–
–
–
999,824
0.12%
2.99
Topography (SLDEM2015) Slope
SLOPE_60M (high-res) SLOPE (low-res)
60.0
963,609
0.00%
60.02
1,000,113
0.00%
56.89
Table 5: Per-modality coverage for the low-resolution and high-resolution tracks. Counts indicate the number of emitted netCDF files for each modality, and Avg Null Pct is the average percent of null pixels per tile. Dataset key indicates the parquet column associated with this modality. Modality resolution for both the high-resolution and low-resolution datasets after resampling procedure also included.
Split
Images
Annotations
Craters / img
Median area
Incidence (°)
Emission (°)
Train
800
91,516
114.4
16.5
72.2
1.81
Val
100
11,429
114.3
16.5
71.1
1.55
Test
100
11,384
113.8
17.0
72.7
1.39
Table 6: WAC Robbins COCO dataset splits with per-split image and annotation counts, mean craters per image, median crater size ( area in px), and mean illumination geometry.
Figure 6: Hand-labeled crater annotations on two NAC study areas, Apollo 15 S-IVB (left) and Apollo 17 (right). Green boxes denote annotated crater instances. Apollo 15 S-IVB was labeled at 5 m/pixel resolution, causing it to appear blurrier than the Apollo 17 image which was labeled at a higher resolution.
Name
Science Theme
Image Size (px)
Resolution (m/px)
Target
Train
Val
Test
Object Detection
Robbins craters
Impact processes
512 × 512
100
1 class
800
100
100
NAC hand labeled
Impact processes
256 × 256
0.8–5
1 class
289
56
63
Segmentation
Irregular Mare Patches
Volcanic History
256 × 256
1
1 class
100
20
10
Regression
Table 7: Overview of SomBench benchmark datasets separated by task type.
Model
mAP
AP@50
AP@75
ResNet-50 (ImageNet)
0.1411 ± 0.0036
0.4374 ± 0.0196
0.0895 ± 0.0055
SwinV2-B (ImageNet)
0.1552 ± 0.0086
0.4586 ± 0.0308
0.1090 ± 0.0146
Table 8: Crater detection on the NAC hand-labeled benchmark (meter-scale LROC NAC imagery). Test-set bounding-box mean average precision: mAP (IoU 0.50:0.95), AP@50, and AP@75. Values are mean ± standard deviation over five random seeds.
Figure 7: Qualitative crater detection results on three test tiles of the NAC hand-labeled benchmark. Columns show the input tile and predictions from SwinV2-B, and ResNet-50 (ImageNet), using the released weights. Green boxes denote ground-truth annotations and red boxes model predictions with confidence ≥ 0.5. Per-panel insets report [email protected] and true-positive, false-positive, and false-negative counts.
50% training data
100% training data
Model
mAP
AP@50
AP@75
mAP
AP@50
AP@75
ResNet-50 (ImageNet)
0.1993 ± 0.0007
0.4960 ± 0.0036
0.1572 ± 0.0038
0.2148 ± 0.0018
0.5288 ± 0.0055
0.1762 ± 0.0038
SwinV2-B (ImageNet)
0.2313 ± 0.0027
0.5849 ± 0.0072
0.1862 ± 0.0041
0.2420 ± 0.0047
0.6020 ± 0.0061
0.2028 ± 0.0086
Table 9: Crater detection on the WAC Robbins catalog benchmark (context-scale LROC WAC imagery) as a function of training-data fraction (left: 50% training data, right: 100%). Test-set bounding-box mean average precision: mAP (IoU 0.50:0.95), AP@50, and AP@75. Values are mean ± standard deviation over five random seeds.
Figure 8: Qualitative crater detection results on three test tiles of the WAC Robbins catalog benchmark at 100% training data. Columns show the input tile and predictions from ResNet-50 (ImageNet) and SwinV2-B, using the released weights. Green boxes denote ground-truth annotations and red boxes model predictions with confidence ≥ 0.5. Per-panel insets report [email protected] and true-positive, false-positive, and false-negative counts.
Model
IoU 1
F1 1
ResNet-50 (ImageNet)
0.4731 ± 0.0114
0.6423 ± 0.0105
SwinV2-B (ImageNet)
0.5555 ± 0.0159
0.7141 ± 0.0132
Table 10: Irregular Mare Patch (IMP) segmentation. Since IMP delineation is a binary dense-prediction task, we report test-set metrics on the positive (IMP) class only: intersection-over-union (IoU 1 ) and F1 score (F1 1 ). Values are mean ± standard deviation over five random seeds.
Figure 9: Qualitative IMP segmentation results on three test tiles. Columns show the input tile, the ground-truth mask, and predictions from ResNet-50 (ImageNet) and SwinV2-B, using the released weights. Yellow denotes the positive (IMP) class, and per-panel insets report the per-tile IoU.
Model
RMSE ↓
MAE ↓
R2↑
ResNet-50 (ImageNet)
0.0788 ± 0.0004
0.0568 ± 0.0004
0.9162 ± 0.0009
SwinV2-B (ImageNet)
0.0377 ± 0.0004
0.0256 ± 0.0003
0.9808 ± 0.0004
Table 11: Polar ice prospectivity regression on the eight-modality polar stack (aspect, slope, ice stability depth, maximum temperature, PSRs, PSR density, distance to PSRs, curvature). Test-set metrics against the prospectivity map in [ 65 ] : for RMSE and MAE lower-is-better, and for R2 higher-is-better. Values are mean ± standard deviation over five random seeds.
Figure 10: Qualitative ice-prospectivity regression results on three polar test patches. Columns show a representative input layer, the target prospectivity map, and predictions from ResNet-50 (ImageNet) and SwinV2-B, using the released weights; per-panel insets report the per-patch MAE.
IBM Research, Yorktown Heights, NY, USA · The University of Alabama in Huntsville, Huntsville, AL, USA · University Space Research Association (USRA), Science and Technology Institute, Huntsville, AL, USA +7