pith. sign in

arxiv: 2606.24028 · v1 · pith:ZCBFK43Lnew · submitted 2026-06-23 · 🌌 astro-ph.EP

Micron-Scale Technosignatures: How a Cubic Metre of Lunar Regolith May Begin to Constrain the Number of Past Technological Civilisations in the Galaxy

Lewis J. Pinault , Brian C. Lacki , Ian A. Crawford , Andrew P. V. Siemion This is my paper

Pith reviewed 2026-06-25 23:23 UTC · model grok-4.3

classification 🌌 astro-ph.EP
keywords technosignatureslunar regolithmicron-scale particlesinterstellar transportartificial debrisexoarchaeologySolar System constraintsnull detection limits
0
0 comments X

The pith

A cubic metre of lunar regolith excludes typical dispersal of more than 0.09 Earth masses of artificial particulate debris per Solar-type star over Galactic history.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper explores whether tiny engineered particles from other civilizations could accumulate in the lunar regolith and be detectable today. It models how refractory grains of roughly 0.3 microns can cross interstellar space over hundreds of millions of years, survive sputtering and drag, and reach the Earth-Moon system through a narrow dynamical channel set by radiation pressure and the heliosphere. The calculation combines particle survival, arrival velocities, and regolith turnover rates to produce a concrete limit: the absence of such grains in one cubic metre would rule out the average Solar-type star having released that much long-lived artificial debris across the Galaxy's lifetime. This sets up a search strategy that turns ordinary lunar samples into a record of past technological activity.

Core claim

The authors show that a null detection in a cubic metre of lunar regolith excludes scenarios in which Solar-type stars typically disperse more than approximately 0.09 Earth mass equivalents of long-lived artificial particulate debris over Galactic history.

What carries the argument

The slow-arrival channel for ~0.3-micron refractory particles, set by solar radiation pressure and heliospheric filtering, that permits a small surviving fraction to reach the Earth-Moon system at low enough velocities for regolith survival.

If this is right

  • A null result in one cubic metre already constrains undirected technomaterial output across the Galaxy.
  • Targeted releases aimed at the inner Solar System raise detection probability by orders of magnitude compared with undirected dispersal.
  • A multi-modal strategy of machine-vision triage followed by laboratory forensic analysis can separate anomalous grains from the natural background.
  • Particulate technosignatures constitute an experimentally accessible channel of exo-archaeology that can return either upper limits or direct material evidence.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The same regolith samples could be cross-checked against existing meteoritic and cosmic-dust collections to test consistency of any anomalous population.
  • If anomalous grains are recovered, isotopic or structural signatures could distinguish artificial from natural origins without requiring in-situ spacecraft visits.
  • Extending the analysis to larger regolith volumes or to asteroid surfaces would tighten the same limit proportionally to the sampled mass.

Load-bearing premise

Particles of characteristic 0.3-micron size can travel kiloparsec distances over 0.1-1 Gyr while remaining intact enough to reach the Moon at survivable speeds.

What would settle it

Direct measurement or simulation showing that 0.3-micron refractory grains are destroyed by ISM sputtering or gas drag before they can cross even 100 parsecs, or that lunar regolith gardening buries or vaporizes arriving grains on timescales much shorter than 0.1 Gyr.

Figures

Figures reproduced from arXiv: 2606.24028 by Andrew P. V. Siemion, Brian C. Lacki, Ian A. Crawford, Lewis J. Pinault.

Figure 1
Figure 1. Figure 1: Illustrative application of the YOLO–ET machine-vision pipeline to a heterogeneous micron-scale particulate field. The image shows a prepared JSC-1 lunar regolith analogue sample containing mixed natural grains and engineered spacecraft-derived particulates. Bounding boxes indicate grain classes identified by the model, in this case, Cesium Astro’s software-defined-radio (SDR) and Nightingale antenna produ… view at source ↗
Figure 2
Figure 2. Figure 2: Constraints on the (MS , ΓS ) megaswarm parameter space derived from a null detection of micron-scale technomaterial in a cubic metre of lunar regolith, for the conservative case of undirected, collisionally generated debris from large engineered swarms subsequently ejected into the ISM by radiation pressure. The grains are assumed to arrive by the slow-arrival channel, and the parameter values are the sta… view at source ↗
Figure 3
Figure 3. Figure 3: Constraints on intentionally dispersed Bracewell Particles (BPs) for micron-sized grains (rG = 1 µm) assuming a 1 m2 search area and an effective sampling time ts = 3.5 Gyr. The axes show the visitation rate ΓV (yr−1 ) versus the mass released per visitation event MV (kg). Different assumptions about the clustering of BPs and sampling lead to different constraints, each plotted as a line. Parameter values … view at source ↗
Figure 4
Figure 4. Figure 4: Axes-of-merit comparison of technosignature classes using the nine-dimensional framework of Sheikh (2020). Grey curves reproduce Sheikhs assessments for radio SETI, optical SETI, infrared Dyson-sphere searches, and Solar System artefacts. Gold and red curves show the qualitative placements of Arkhipov Particles (APs) and Bracewell Particles (BPs) introduced in this work: the AP trace reflects the undirecte… view at source ↗
Figure 5
Figure 5. Figure 5: Sketch of the geometry of the optimal trajectory (light red) for grain capture, in which the grain’s perihelion exactly coincides with the Earth–Moon orbit, modelled as circular (light blue). Top: the grain enters from infinity with a speed less than the Earth–Moon orbital velocity; β < 1 and gravitation overpowers radiation to accelerate it. Bottom: the grain enters from infinity with a speed greater than… view at source ↗
read the original abstract

Building on Arkhipov's proposal that technogenic artefacts may survive natural interstellar transport and accumulate on airless Solar System bodies, we examine the prospects for identifying micron-scale engineered particulate material within the lunar regolith. We analyse the transport of micron and submicron grains through the interstellar medium, including gas drag, sputtering, and ISM phase-dependent survival, and show that refractory particles with characteristic radii of order 0.3 microns may traverse kiloparsec scales over residence times of 0.1-1 Gyr. Solar radiation pressure and heliospheric filtering define a dynamically constrained slow-arrival channel in which a small fraction of grains reach the Earth-Moon system at relative velocities compatible with survival upon impact. Combining these properties with regolith-mixing constraints yields quantitative upper limits on the cumulative undirected technomaterial output of large-scale spacefaring civilisations: a null detection in a cubic metre of regolith excludes scenarios in which Solar-type stars typically disperse more than approximately 0.09 Earth mass equivalents of long-lived artificial particulate debris over Galactic history. Deliberate targeting of the inner Solar System with artificial particulate matter defines a complementary regime characterised by the visitation frequency and deposited mass of such releases, for which the probabilities of detection may be orders of magnitude higher. We outline a multi-modal detection strategy integrating machine-vision triage with laboratory forensic techniques to identify anomalous grains within a well-characterised natural background. Particulate technosignatures thus establish an experimentally accessible form of exo-archaeology, capable of placing meaningful constraints -- and, in favourable cases, yielding direct material evidence -- of the Galaxy's technological history.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 1 minor

Summary. The paper claims that modeling the interstellar transport of ~0.3 μm refractory artificial particles (including gas drag, sputtering, radiation pressure, and heliospheric filtering) shows that a small fraction can reach the Earth-Moon system at survivable velocities over 0.1-1 Gyr residence times. Combined with regolith mixing constraints, a null detection in 1 m³ of lunar regolith excludes scenarios in which Solar-type stars typically disperse more than ~0.09 M_⊕ of long-lived technogenic particulate debris over Galactic history. It also outlines a multi-modal detection strategy for such grains.

Significance. If the transport and survival calculations are robust, the work would establish a new, experimentally accessible channel for constraining the cumulative technomaterial output of spacefaring civilizations, converting lunar regolith sampling into a quantitative probe of galactic technological history. The approach is distinctive in deriving a specific numerical exclusion limit from physical transport models rather than direct observation.

major comments (2)
  1. [Transport analysis] Transport analysis (abstract and implied § on ISM traversal): the headline 0.09 M_⊕ exclusion limit is directly proportional to the modeled arrival fraction of 0.3 μm grains. No sensitivity analysis or error propagation is evident for key inputs (particle radius, residence time, sputtering yields, optical constants); if the net survival/arrival efficiency is overestimated by even 2–3 orders of magnitude, the quantitative constraint vanishes. This is load-bearing for the central claim.
  2. [Regolith-mixing constraints] Regolith-mixing and sampling section: the translation from arrival rate to the specific 0.09 M_⊕ per star limit requires explicit equations linking mixing depth, 1 m³ volume, and Galactic stellar density; without these the numerical result cannot be reproduced or tested.
minor comments (1)
  1. [Abstract] The abstract states the 0.09 M_⊕ figure but does not list the free parameters or the exact functional dependence on arrival fraction; this should be made explicit in the main text.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for their constructive comments on the transport modeling and the derivation of the quantitative limit. We address each major point below.

read point-by-point responses

  1. Referee: [Transport analysis] Transport analysis (abstract and implied § on ISM traversal): the headline 0.09 M_⊕ exclusion limit is directly proportional to the modeled arrival fraction of 0.3 μm grains. No sensitivity analysis or error propagation is evident for key inputs (particle radius, residence time, sputtering yields, optical constants); if the net survival/arrival efficiency is overestimated by even 2–3 orders of magnitude, the quantitative constraint vanishes. This is load-bearing for the central claim.

    Authors: We agree that the absence of a sensitivity analysis leaves the robustness of the arrival fraction insufficiently demonstrated. The manuscript presents baseline transport calculations but does not quantify how variations in particle radius, residence time, sputtering yields, or optical constants propagate to the net efficiency. In the revised version we will add a dedicated subsection with sensitivity tests on these parameters, including order-of-magnitude variations and a simple error-propagation estimate, to show the range of arrival fractions over which the 0.09 M_⊕ limit remains valid. revision: yes

  2. Referee: [Regolith-mixing constraints] Regolith-mixing and sampling section: the translation from arrival rate to the specific 0.09 M_⊕ per star limit requires explicit equations linking mixing depth, 1 m³ volume, and Galactic stellar density; without these the numerical result cannot be reproduced or tested.

    Authors: We acknowledge that the manuscript states the final numerical limit without displaying the full chain of equations that connect grain arrival rate, regolith mixing depth, the 1 m³ sampling volume, and the assumed Galactic density of Solar-type stars. The revised manuscript will include an expanded methods section or appendix that presents these linking equations explicitly, allowing the 0.09 M_⊕ per star exclusion limit to be reproduced from the arrival fraction and the adopted stellar density. revision: yes

Circularity Check

0 steps flagged

No significant circularity; derivation relies on independent physical models

full rationale

The paper derives its 0.09 M_⊕ upper limit by combining external transport physics (gas drag, sputtering, radiation pressure, heliospheric filtering), survival estimates, and regolith-mixing constraints applied to a hypothetical null detection. No step reduces by construction to a fitted parameter, self-citation chain, or renamed input; the central quantitative claim is a forward model prediction from stated assumptions rather than a tautology. Self-citations, if present, are not load-bearing for the exclusion limit. The derivation is therefore self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

2 free parameters · 2 axioms · 0 invented entities

The 0.09 Earth mass limit depends on several model parameters and assumptions about particle physics and lunar surface processes not fully specified in the abstract.

free parameters (2)
  • particle radius = 0.3 microns
    Characteristic size used in transport calculations
  • residence time = 0.1-1 Gyr
    Timescale for particle survival and travel
axioms (2)
  • domain assumption Refractory particles can survive ISM sputtering and gas drag over galactic distances
    Central to the transport analysis in the abstract
  • domain assumption Regolith mixing allows accumulation of particles over galactic history
    Used to derive the quantitative upper limits

pith-pipeline@v0.9.1-grok · 5855 in / 1402 out tokens · 44259 ms · 2026-06-25T23:23:01.756669+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

197 extracted references · 56 canonical work pages

  1. [1]

    R., Schiavon, R

    Anguiano, B., Majewski, S. R., Schiavon, R. P., et al. (2018). The chemo-dynamical structure of the Milky Way disk. Monthly Notices of the Royal Astronomical Society 474, 854--865. doi:10.1093/mnras/stx2819

    work page doi:10.1093/mnras/stx2819 2018

  2. [2]

    Arkhipov, A. V. (1993). The Moon as attractor of alien artifacts. Selenology, Journal of the American Lunar Society 12(1), 6

    1993

  3. [3]

    Arkhipov, A. V. (1994a). Search for alien artifacts on the Moon: a justification. RIAP Bulletin 1(2), 9

  4. [4]

    Arkhipov, A. V. (1994b). Invasion effect on the Moon. Selenology, Journal of the American Lunar Society 13(1), 9

  5. [5]

    Arkhipov, A. V. (1995). A search for alien artifacts on the Moon. In Progress in the Search for Extraterrestrial Life, ASP Conference Series, Vol. 74, ed. G. S. Shostak (San Francisco, CA: Astronomical Society of the Pacific), 259--262

    1995

  6. [6]

    Arkhipov, A. V. (1996). Extraterrestrial artefacts. The Observatory 116, 175--176

    1996

  7. [7]

    Arkhipov, A. V. (1997). Extraterrestrial technogenic component of the meteoroid flux. Astrophysics and Space Science, 252, 67--71. doi:10.1023/A:1000801830046

    work page doi:10.1023/a:1000801830046 1997

  8. [8]

    Arkhipov, A. V. (1998). Earth--Moon system as a collector of alien artifacts. Journal of the British Interplanetary Society 51, 181--184

    1998

  9. [9]

    M., Grevesse, N

    Asplund, M., Amarsi, A. M., Grevesse, N. The chemical make-up of the Sun: A 2020 vision. Astronomy & Astrophysics, 653, A141

    2020

  10. [10]

    Ball, J. A. (1973). The zoo hypothesis. Icarus 19(3), 347--349

    1973

  11. [11]

    & Palicio, P

    Barbillon, M., Recio-Blanco, A., de Laverny, P. & Palicio, P. A. (2025). 3D extinction maps of the Milky Way disc from Gaia GSP-Spec parameters. arXiv e-prints, arXiv:2511.12156

    arXiv 2025

  12. [12]

    & Benford, D

    Benford, J., Benford, G. & Benford, D. (2019). Looking for Lurkers: Objects Co-orbital with Earth as SETI Observables. Acta Astronautica 161, 365--373

    2019

  13. [13]

    Benford, J. (2021). A Drake Equation for alien artifacts. Astrobiology 21(6), 722--729

    2021

  14. [14]

    The Galaxy in Context: Structural, Kinematic and Integrated Properties

    Bland-Hawthorn, J. & Gerhard, O. (2016). The Galaxy in context: Structural, kinematic, and integrated properties. Annual Review of Astronomy and Astrophysics 54, 529--596. doi:10.1146/annurev-astro-081915-023441

    work page Pith review doi:10.1146/annurev-astro-081915-023441 2016

  15. [15]

    Bovy, J. (2017). The Milky Way's stellar disk. Monthly Notices of the Royal Astronomical Society 470, 1360--1381

    2017

  16. [16]

    Bracewell, R. N. (1960). Communications from superior galactic communities. Nature 186, 670--671. doi:10.1038/186670a0

    work page doi:10.1038/186670a0 1960

  17. [17]

    Session on Biological Technosignatures and Genomic SETI

    Breakthrough Discuss Conference (2019). Session on Biological Technosignatures and Genomic SETI. Stanford University, 11--12 April 2019

    2019

  18. [18]

    Burgess, K. D. & Stroud, R. M. (2018). Phase-dependent space weathering effects and spectroscopic identification of retained helium in a lunar soil grain. Geochimica et Cosmochimica Acta 224, 64--79. doi:10.1016/j.gca.2017.12.023

    work page doi:10.1016/j.gca.2017.12.023 2018

  19. [19]

    J., et al

    Burchell, M. J., et al. (1999). Hypervelocity impact studies using the 2 MV Van de Graaff accelerator and two-stage light gas gun. Measurement Science and Technology 10(1), 41--50

    1999

  20. [20]

    J., Mann, J., Bunch, A

    Burchell, M. J., Mann, J., Bunch, A. W., & Brand \ a o, P. F. B. (2001). Survivability of bacteria in hypervelocity impact. Icarus 154(2), 545--547

    2001

  21. [21]

    J., Mann, J

    Burchell, M. J., Mann, J. R., & Bunch, A. W. (2004). Survival of bacteria and spores under extreme shock pressures. Monthly Notices of the Royal Astronomical Society 352(4), 1273--1278

    2004

  22. [22]

    Burchell, M. J. (2006). W(h)ither the Drake equation? International Journal of Astrobiology 5(3), 243--250

    2006

  23. [23]

    J., Graham, G

    Burchell, M. J., Graham, G. A., & Kearsley, A. T. (2008). Survival of meteoritic material in hypervelocity impacts. International Journal of Impact Engineering 35(10), 987--993

    2008

  24. [24]

    Carrigan, R. A. (2009). IRAS-based whole-sky upper limit on Dyson spheres. The Astrophysical Journal 698, 2075--2086. doi:10.1088/0004-637X/698/2/2075

    work page doi:10.1088/0004-637x/698/2/2075 2009

  25. [25]

    SDR-2104 software-defined radio module

    CesiumAstro (2024). SDR-2104 software-defined radio module. Available at: https://www.cesiumastro.com/products/sdr-2104 (accessed 2026)

    2024

  26. [26]

    Chabrier, G. (2003). Galactic stellar and substellar initial mass function. Publications of the Astronomical Society of the Pacific 115, 763--795

    2003

  27. [27]

    Ćirković, M. M. (2018). The Great Silence: Science and Philosophy of Fermi’s Paradox. Oxford University Press, Oxford

    2018

  28. [28]

    Clarke, A. C. (1951). The Sentinel. Avon Science Fiction and Fantasy Reader. Avon Periodicals

    1951

  29. [29]

    Cocconi, G., & Morrison, P. (1959). Searching for interstellar communications. Nature 184, 844--846

    1959

  30. [30]

    Colaprete, A., Schultz, P., Heldmann, J., et al. (2022). Commercial Lunar Payload Services: Enabling rapid and sustained lunar surface access. Space Science Reviews 218, 11. doi:10.1007/s11214-022-00893-6

    work page doi:10.1007/s11214-022-00893-6 2022

  31. [31]

    S., Ghent, R

    Costello, E. S., Ghent, R. R., & Lucey, P. G. (2018). The mixing of lunar regolith: Vital updates to a canonical model. Icarus 314, 327--344

    2018

  32. [32]

    S., Ghent, R

    Costello, E. S., Ghent, R. R., Hirabayashi, M., & Lucey, P. G. (2020). Impact Gardening as a Constraint on the Age, Source, and Evolution of Ice on Mercury and the Moon. Journal of Geophysical Research (Planets) 125(3), e06172

    2020

  33. [33]

    S., Ghent, R

    Costello, E. S., Ghent, R. R., & Lucey, P. G. (2021). Secondary impact burial and excavation gardening on the Moon and the depth to ice in permanent shadow. Journal of Geophysical Research: Planets 126(9), e2021JE006933

    2021

  34. [34]

    Crawford, I. A. (2006). The astrobiological case for renewed robotic and human exploration of the Moon. International Journal of Astrobiology 5, 191--197

    2006

  35. [35]

    A., Anand, M., Cockell, C

    Crawford, I. A., Anand, M., Cockell, C. S., Falcke, H., Green, D. A., Jaumann, R. and Wieczorek, M. A. (2012). Back to the Moon: The scientific rationale for resuming lunar surface exploration. Planetary and Space Science 74, 3--14. doi:10.1016/j.pss.2012.08.003

    work page doi:10.1016/j.pss.2012.08.003 2012

  36. [36]

    Crawford, I. A. (2016). The Moon as a recorder of nearby supernovae. In: Handbook of Supernovae, eds. A. W. Alsabti & P. Murdin. Springer, Cham, pp. 2541--2560

    2016

  37. [37]

    A., Joy, K

    Crawford, I. A., Joy, K. H., Pasckert, J. H. and Hiesinger, H. (2021). The lunar surface as a recorder of astrophysical processes. Philosophical Transactions of the Royal Society A 379, 20190562. doi:10.1098/rsta.2019.0562

    work page doi:10.1098/rsta.2019.0562 2021

  38. [38]

    & Pinault, L

    Crawford, I.\ A. & Pinault, L. J. (2023). Constraining the Fermi paradox: the case for keeping eyes (and minds) open for technosignatures on the Moon. European Lunar Symposium 2023, abstract

    2023

  39. [39]

    A., & Schulze-Makuch, D

    Crawford, I. A., & Schulze-Makuch, D. (2024). Is the apparent absence of extraterrestrial technological civilizations down to the zoo hypothesis or nothing? Nature Astronomy 8, 44--49

    2024

  40. [40]

    Dartois, E., Engrand, C., Brunetto, R., Duprat, J., Pino, T., Quirico, E., Remusat, L., et al. (2013). Ultra-carbonaceous Antarctic micrometeorites: probing the solar system beyond the nitrogen snow-line. Icarus 224(1), 243--252

    2013

  41. [41]

    Davies, P. (2012). Footprints of alien technology in DNA? Acta Astronautica, 73, 250--257

    2012

  42. [42]

    Davies, P. C. W., & Wagner, R. V. (2013). Searching for alien artifacts on the Moon. Acta Astronautica, 89, 261--269

    2013

  43. [43]

    Deamer, D. W. (2011). First Life: Discovering the Connections Between Stars, Cells, and How Life Began. University of California Press

    2011

  44. [44]

    W., & Szostak, J

    Deamer, D. W., & Szostak, J. W. (2019). The Origins of Life. Oxford University Press

    2019

  45. [45]

    de Avillez, M. A. & Mac Low, M.-M. (2002). The global evolution of the interstellar medium in star-forming galaxies. The Astrophysical Journal 581, 1047--1060. doi:10.1086/344256

    work page doi:10.1086/344256 2002

  46. [46]

    de Avillez, M. A. & Mac Low, M.-M. (2007). Mixing timescales in a supernova-driven interstellar medium. The Astrophysical Journal 665, 35--43. doi:10.1086/519271

    work page doi:10.1086/519271 2007

  47. [47]

    In: Proceedings of the IEEE Conference on Computer Vision and Pat- tern Recognition, pp

    Deng, J., Dong, W., Socher, R., Li, L.-J., Li, K. & Fei-Fei, L. (2009). ImageNet: A large-scale hierarchical image database. In Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition (CVPR 2009), Miami, FL, USA, 248--255. doi:10.1109/CVPR.2009.5206848

    work page doi:10.1109/cvpr.2009.5206848 2009

  48. [48]

    W., Manson, N

    Doherty, M. W., Manson, N. B., Delaney, P., Jelezko, F., Wrachtrup, J. & Hollenberg, L. C. L. (2013). The nitrogen–vacancy centre in diamond. Physics Reports 528, 1–45

    2013

  49. [49]

    T., & Salpeter, E

    Draine, B. T., & Salpeter, E. E. (1979). Destruction mechanisms for interstellar dust. Astrophysical Journal 231, 77--94. doi:10.1086/157165

    work page doi:10.1086/157165 1979

  50. [50]

    Draine, B. T. (2011). Physics of the Interstellar and Intergalactic Medium. Princeton University Press, Princeton, NJ

    2011

  51. [51]

    T., Aniano, G., Chen, C.-A., et al

    Draine, B. T., Aniano, G., Chen, C.-A., et al. (2014). The dust and gas content of M31. Astrophysical Journal 780, 172

    2014

  52. [52]

    Drake, F. D. (1961). Project Ozma. Physics Today 14(4), 40--46

    1961

  53. [53]

    & Spergel, D

    Drimmel, R. & Spergel, D. N. (2001). Three-dimensional structure of the Milky Way disk: The distribution of stars and dust. Astrophysical Journal 556, 181--202

    2001

  54. [54]

    G., Childress, L., Jiang, L., Togan, E., Maze, J., Jelezko, F., Wrachtrup, J., Hemmer, P

    Dutt, M. G., Childress, L., Jiang, L., Togan, E., Maze, J., Jelezko, F., Wrachtrup, J., Hemmer, P. R. & Lukin, M. D. (2007). Quantum register based on individual electronic and nuclear spin qubits in diamond. Science 316, 1312–1316

    2007

  55. [55]

    Dyson, F. J. (1960). Search for artificial stellar sources of infrared radiation. Science 131(3414), 1667--1668

    1960

  56. [56]

    Ellery, A. (2022). The prospect of von Neumann probes and the implications for the Sagan--Tipler debate. International Journal of Astrobiology 21(4), 197--199

    2022

  57. [57]

    Ellery, A. (2025). Von Neumann probes revisited: mechanical, informational, and material constraints on cosmic self-replication. arXiv:2510.00082 [astro-ph.IM]

    arXiv 2025

  58. [58]

    Feynman, R.\ P., Leighton, R.\ B., & Sands, M.\ L. (1964). The Feynman Lectures on Physics, Vol.\ I. Addison--Wesley, Reading, MA

    1964

  59. [59]

    Feynman, R.\ P., Leighton, R.\ B., & Sands, M.\ L. (1964). Exercises and Problems in The Feynman Lectures on Physics, Vol.\ I. Addison--Wesley, Reading, MA

    1964

  60. [60]

    Flynn, G. J. (1994). Interplanetary dust particles collected from the stratosphere: physical, chemical, and mineralogical properties and implications for their sources. Planetary and Space Science 42(12), 1151--1161

    1994

  61. [61]

    Forgan, D., & Elvis, M. (2011). Extrasolar asteroid mining as a source of technosignatures. International Journal of Astrobiology, 10(4), 307--315

    2011

  62. [62]

    Foster, G. V. (1972). On the search for extraterrestrial artefacts in the Solar System. Journal of the British Interplanetary Society 25, 407--412

    1972

  63. [63]

    Freitas, R. A. Jr. (1983). The search for extraterrestrial artifacts (SETA). Journal of the British Interplanetary Society 36, 501--506

    1983

  64. [64]

    Freitas, R. A. Jr., & Valdes, F. (1980). A search for natural or artificial objects located at the Earth--Moon libration points. Icarus 42, 442--447

    1980

  65. [65]

    Freitas, R. A. Jr., & Valdes, F. (1985). The search for extraterrestrial artifacts (SETA). Acta Astronautica 12, 1027--1034

    1985

  66. [66]

    C., Redfield, S., & Slavin, J

    Frisch, P. C., Redfield, S., & Slavin, J. D. (2011). The interstellar medium surrounding the Sun. Annual Review of Astronomy and Astrophysics 49, 237--279. doi:10.1146/annurev-astro-081710-102613

    work page doi:10.1146/annurev-astro-081710-102613 2011

  67. [67]

    J., Van Ginneken, M., & Suttle, M

    Genge, M. J., Van Ginneken, M., & Suttle, M. D. (2020). Micrometeorites: insights into the flux, sources and atmospheric entry of extraterrestrial dust at Earth. Planetary and Space Science 187, 104900

    2020

  68. [68]

    J., Almeida, N., Van Ginneken, M., Pinault, L

    Genge, M. J., Almeida, N., Van Ginneken, M., Pinault, L. J., Wozniakiewicz, P., & Yano, H. (2023). Ice and liquid water in asteroid Ryugu: constraints from sample A0180. 14th Symposium on Polar Science, National Institute of Polar Research, Tachikawa, Tokyo, 14--17 November 2023

    2023

  69. [69]

    J., Almeida, N

    Genge, M. J., Almeida, N. V., Van Ginneken, M., Pinault, L. J., Wozniakiewicz, P. J., & Yano, H. (2024a). Evidence from 162173 Ryugu for the influence of freeze--thaw on the hydration of asteroids. Nature Astronomy. doi:10.1038/s41550-024-02369-7

    work page doi:10.1038/s41550-024-02369-7

  70. [70]

    J., Almeida, N

    Genge, M. J., Almeida, N. V., Van Ginneken, M., Pinault, L. J., Wozniakiewicz, P. J., & Yano, H. (2024b). The discovery of a large porphyritic chondrule in 162173 Ryugu. 86th Annual Meeting of the Meteoritical Society, LPI Contribution No. 3036

  71. [71]

    Gharsallaoui, A., Chambin, O., Cases, E., & Saurel, R. (2022). Microencapsulation: an updated review of technologies and their applications. Trends in Food Science & Technology 127, 156--173. doi:10.1016/j.tifs.2022.06.021

    work page doi:10.1016/j.tifs.2022.06.021 2022

  72. [72]

    Goodfellow, I., Bengio, Y., & Courville, A. (2016). Deep learning. MIT Press

    2016

  73. [73]

    M., Schlafly, E

    Green, G. M., Schlafly, E. F., Zucker, C., Speagle, J. S. & Finkbeiner, D. P. (2019). A 3D dust map based on Gaia, Pan-STARRS 1, and 2MASS. Astrophysical Journal 887, 93

    2019

  74. [74]

    Grind, K. (2025). Now tech moguls want to build data centers in outer space. The Wall Street Journal, 16 November 2025. https://www.wsj.com/tech/now-tech-moguls-want-to-build-data-centers-in-outer-space-a8d08b4b

    2025

  75. [75]

    Grün, E., Horányi, M., & Sternovsky, Z. (2011). The lunar dust environment. Planetary and Space Science 59(14), 1672--1680

    2011

  76. [76]

    Gu, L., Lin, Y., Chen, Y., Xu, Y., Tang, X. & Li, J. (2025). Submicron-scale craters on Chang’e-5 lunar soils: records of complex space weathering processes. Geochimica et Cosmochimica Acta 398, 139--151. doi:10.1016/j.gca.2025.04.004

    work page doi:10.1016/j.gca.2025.04.004 2025

  77. [77]

    & Liu, C

    Guo, R., Li, Z.-Y., Shen, J., Mao, S. & Liu, C. (2024). Measuring the Milky Way vertical potential with the phase snail in a model-independent way. The Astrophysical Journal 960(2), 133. doi:10.3847/1538-4357/ad037b

    work page doi:10.3847/1538-4357/ad037b 2024

  78. [78]

    Haase, I., Oberst, J., Scholten, F., Wählisch, M., Gläser, P., Karachevtseva, I., & Robinson, M. (2012). Mapping the Apollo 17 landing site using LRO camera images and Apollo surface photography. Journal of Geophysical Research: Planets 117, E00H24

    2012

  79. [79]

    & Kopparapu, R

    Haqq-Misra, J. & Kopparapu, R. K. (2012). On the likelihood of non-terrestrial artifacts in the Solar System. Acta Astronautica 72, 15--20. doi:10.1016/j.actaastro.2011.10.010

    work page doi:10.1016/j.actaastro.2011.10.010 2012

  80. [80]

    A., Farah, W., Fauchez, T

    Haqq-Misra, J., Ashtari, R., Benford, J., Carroll-Nellenback, J., D\"obler, N. A., Farah, W., Fauchez, T. J., Gajjar, V., Grinspoon, D., Huggahalli, A., Kopparapu, R. K., Lazio, J., Profitiliotis, G., Sneed, E. L., Shynu Varghese, S. & Vidal, C. (2022). Opportunities for technosignature science in the Planetary Science and Astrobiology Decadal Survey. arX...

    arXiv 2022

Showing first 80 references.