Planetary Science

Deep Impact (EPOXI - Extrasolar Planet Observation and Deep Impact Extended Investigation) (Deep Impact (EPOXI))

Impactor · Competed · PI-led · Launched on January 12, 2005 · Completed · LCC: $342M/$624M (2025 $)Life-cycle cost: NASA’s reported cost to build, launch, and operate a mission through its prime mission, plus documented partner contributions, in 2025 dollars. Extended missions are not included. Methods · Wikipedia

Scope Active Mission WindowActivePapers published from the first full month after science operations begin through two years after the mission ends. Citations are counted through the third calendar year after each paper appears. For Deep Impact (EPOXI), papers published July 1, 2005 to October 1, 2015. Methods LifetimeLifetimeEvery tracked publication to date, with every citation to date. For Deep Impact (EPOXI), papers published from 2005 to November 3, 2026. Methods
Tracked publicationsTracked publications: peer-reviewed papers we found that name the mission or its instruments in their titles, abstracts, or keywords. Papers that used the data without naming it are missed. Methods314
CitationsCitations: every citation these publications have drawn to date. Older missions have had longer to collect them. Methods12,211
Citation indices
h-indexh-index: the largest h such that h papers have at least h citations each. It only grows with time, so older missions score higher. Methods56
g-indexg-index: the largest g for which the g most-cited papers together hold at least g² citations. Like the h-index, but it lets the most-cited papers count for more. Methods99
m-indexm-index: a mission’s h-index divided by the years since its first peer-reviewed paper. It falls every 1 January even when nothing else changes; the figure shown is as of November 3, 2026. It also discounts the long operating life that larger missions paid for. Methods2.5
toritori (total research impact, from SciX): for every paper citing one of the mission’s papers, 1 divided by the citing paper’s reference count times the cited paper’s author count, summed, with self-citations removed. It favors citations from papers with short reference lists and from outside the mission’s own authors. Computed over the tracked citation graph, which can be slightly incomplete. Always over every tracked publication to date, whichever scope is chosen. Methods58
riqriq (research impact quotient): 1,000 times the square root of tori, divided by the years since the mission’s first paper. A rate, not a total, so it does not keep growing with age the way the h-index and tori do. Like tori, always over every tracked publication to date. Methods346

Publications and citations by year (lifetime)

Publications per yearCumulative citations

Institutional contributions (lifetime)The institutions SciX lists for each paper’s authors, as printed on the paper, located through the Research Organization Registry. A square counts a paper once, however many of its authors worked there. Methods

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Tracked publications over the lifetime (314)

All publications CSV · JSON

  1. Deep Impact: Excavating Comet Tempel 1

    A'Hearn, M. F., 2005, Sci

    720 lifetime citations

  2. Homogeneous studies of transiting extrasolar planets - IV. Thirty systems with space-based light curves

    Southworth, John, 2011, MNRAS

    534 lifetime citations

  3. Temporal and Spatial Variability of Lunar Hydration As Observed by the Deep Impact Spacecraft

    Sunshine, Jessica M., 2009, Sci

    447 lifetime citations

  4. EPOXI at Comet Hartley 2

    A'Hearn, Michael F., 2011, Sci

    438 lifetime citations

  5. Spitzer Spectral Observations of the Deep Impact Ejecta

    Lisse, C. M., 2006, Sci

    298 lifetime citations

  6. Exposed Water Ice Deposits on the Surface of Comet 9P/Tempel 1

    Sunshine, J. M., 2006, Sci

    238 lifetime citations

  7. A crater and its ejecta: An interpretation of Deep Impact

    Holsapple, Keith A., 2007, Icar

    217 lifetime citations

  8. Ultra-primitive interplanetary dust particles from the comet 26P/Grigg-Skjellerup dust stream collection

    Busemann, Henner, 2009, E&PSL

    201 lifetime citations

  9. A ballistics analysis of the Deep Impact ejecta plume: Determining Comet Tempel 1's gravity, mass, and density

    Richardson, James E., 2007, Icar

    193 lifetime citations

  10. Alien Maps of an Ocean-bearing World

    Cowan, Nicolas B., 2009, ApJ

    189 lifetime citations

  11. The primordial nucleus of comet 67P/Churyumov-Gerasimenko

    Davidsson, B. J. R., 2016, A&A

    172 lifetime citations

  12. Earth as an Extrasolar Planet: Earth Model Validation Using EPOXI Earth Observations

    Robinson, Tyler D., 2011, AsBio

    170 lifetime citations

  13. Deep Impact: Observations from a Worldwide Earth-Based Campaign

    Meech, K. J., 2005, Sci

    168 lifetime citations

  14. Parent Volatiles in Comet 9P/Tempel 1: Before and After Impact

    Mumma, Michael J., 2005, Sci

    148 lifetime citations

  15. A large dust/ice ratio in the nucleus of comet 9P/Tempel 1

    Küppers, Michael, 2005, Natur

    132 lifetime citations

  16. Shape, density, and geology of the nucleus of Comet 103P/Hartley 2

    Thomas, P. C., 2013, Icar

    126 lifetime citations

  17. A distribution of large particles in the coma of Comet 103P/Hartley 2

    Kelley, Michael S., 2013, Icar

    124 lifetime citations

  18. The shape, topography, and geology of Tempel 1 from Deep Impact observations

    Thomas, Peter C., 2007, Icar

    123 lifetime citations

  19. Surface temperature of the nucleus of Comet 9P/Tempel 1

    Groussin, O., 2007, Icar

    121 lifetime citations

  20. Water ice and dust in the innermost coma of comet 103P/Hartley 2

    Protopapa, Silvia, 2014, Icar

    117 lifetime citations

How we found these papers

We searched NASA’s Science Explorer (SciX) for peer-reviewed articles naming Deep Impact (EPOXI) in the title, abstract or keywords; standard filters drop articles that are not peer-reviewed and magazine pieces.

(((=abs:"Deep Impact" AND (=abs:"Tempel 1" OR abs:Tempel OR abs:Hartley OR abs:EPOXI OR abs:EPOCh OR abs:lunar OR abs:Moon OR =abs:"Deep Impact spacecraft" OR =abs:"Deep Impact mission" OR =abs:"Deep Impact flyby" OR =abs:"Deep Impact experiment" OR =abs:"Deep Impact encounter")) OR (abs:EPOXI AND (abs:comet OR abs:Hartley OR abs:exoplanet OR abs:transit OR abs:Earth OR abs:lunar OR abs:Moon OR abs:planet)) OR (abs:DIXI AND abs:Hartley))) AND property:refereed AND doctype:article AND pubdate:[2005-07 TO 2040-01] AND NOT bibstem:("A&R" OR "ACPD" OR "AIASJ" OR "AMTD" OR "AeAm" OR "AirSp" OR "AsNow" OR "AsUAI" OR "AvWST" OR "BGD" OR "C&E" OR "C&T" OR "CAPJ" OR "CliPD" OR "E&S" OR "ENews" OR "ESDD" OR "ESSDD" OR "ESuDD" OR "GID" OR "GMDD" OR "GeCAS" OR "HESSD" OR "IrAJ" OR "JCos" OR "JRASC" OR "LAstr" OR "MNSSA" OR "Met" OR "NHESD" OR "NPGD" OR "NewSc" OR "OcScD" OR "Orion" OR "PhT" OR "PhTea" OR "PhuZ" OR "PhyOJ" OR "PhyW" OR "PlR" OR "SOILD" OR "SciAm" OR "SpFl" OR "TCD" OR "ZemVs")

Open in SciX

Added after review (3)

  1. Parent Volatiles in Comet 9P/Tempel 1: Before and After Impact Ground-based measurements of the ejecta from the Deep Impact collision with comet Tempel 1. Decision 🤖
  2. The impact and rotational light curves of Comet 9P/Tempel 1 Ground-based light curves of comet Tempel 1 during the Deep Impact collision. Decision 🤖
  3. The nucleus of Comet 9P/Tempel 1: Shape and geology from two flybys Comet Tempel 1 nucleus geology from Deep Impact and Stardust-NExT imaging. Decision 🤖

Removed after review (6)

  1. Deep Impact: sifting through the debris Nature news article about the mission; not a research paper. Decision 👨
  2. Hydrogen cyanide polymers, comets and the origin of life Mentions Deep Impact only as a possible future source of evidence; uses none of its data. Decision 🤖
  3. Deep Impact at Comet Tempel 1: Part 2 Editorial preface to a journal special issue; not a research paper. Decision 🤖
  4. Deep Impact on Hartley 2 Journal editorial summary of another paper; not a research paper. Decision 🤖
  5. 2005Orion..63f..11S Amateur-astronomy magazine news report; not a research paper. Decision 🤖
  6. Alice: The rosetta Ultraviolet Imaging Spectrograph Instrument description of the Rosetta Alice ultraviolet spectrograph; Deep Impact is mentioned only as an observing campaign. Decision 🤖