Planetary Science

Deep Impact (EPOXI)

314 tracked publications and 12,039 citations from 2005–2026. Deep Impact (EPOXI - Extrasolar Planet Observation and Deep Impact Extended Investigation). Launched 2005. Life-cycle cost: $624M in 2025 dollars. Active Mission Window July 1, 2005 to October 1, 2015: 276 publications, 30 top-10% credit.

Impactor · h-index 56 · 27 papers with 100+ citations · prime mission ended 2005

Lifetime

Scope Papers published from the first full month after science operations begin through 2 years after the mission ends. Citations are counted through the third calendar year after each paper appears. Methods Papers published from the first full month after science operations begin through 2 years after the prime mission ends. Citations are counted through the third calendar year after each paper appears. Methods Every tracked publication to date, with every citation to date. Methods

Key measures

Active Mission Window · papers July 1, 2005 to October 1, 2015
Tracked publicationsTracked publications: peer-reviewed research papers we found for the mission. The list may not be complete. Methods276
CitationsCitations received by the tracked publications in the selected scope. The two windowed scopes count each paper’s citations only within its citation window. Methods3,939
Mean citations per publicationMean citations: total citations divided by tracked publications in the selected scope. One blockbuster paper can lift it. Methods14
Median citations per publicationMedian citations: the middle paper’s citation count in the selected scope; half the papers have more, half fewer. A single blockbuster sways it less than the mean. Methods6
Uncited publicationsUncited publications: papers with no citations in the selected scope. Methods16 (5.8%)
Top-10% creditTop 10%: among the 10% most-cited papers from this division’s missions, ranked against papers published around the same time. A paper naming several missions is split evenly among the missions in this division that claim it, so counts can be fractional. Methods30 · 2.7% of division
Top-1% creditTop 1%: among the 1% most-cited papers from this division’s missions within the selected window. Not adjusted for publication year. A paper naming several missions is split evenly among the missions in this division that claim it, so counts can be fractional. Methods4.0 · 3.7% of division
Lifetime indices · every tracked publication to date, in any scope
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. Methods98
m-index, as of October 4, 2026m-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, so it belongs to the date shown; it also discounts the long operating life that larger missions paid for. Methods2.5
toritori (total research impact, from ADS): 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. Methods53
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. Methods331

Tracked publications

  1. Deep Impact: Excavating Comet Tempel 1

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

    712 citations

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

    Southworth, John, 2011, MNRAS

    529 citations

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

    Sunshine, Jessica M., 2009, Sci

    440 citations

  4. EPOXI at Comet Hartley 2

    A'Hearn, Michael F., 2011, Sci

    435 citations

  5. Spitzer Spectral Observations of the Deep Impact Ejecta

    Lisse, C. M., 2006, Sci

    292 citations

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

    Sunshine, J. M., 2006, Sci

    234 citations

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

    Holsapple, Keith A., 2007, Icar

    217 citations

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

    Busemann, Henner, 2009, E&PSL

    199 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 citations

  10. Alien Maps of an Ocean-bearing World

    Cowan, Nicolas B., 2009, ApJ

    185 citations

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

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

    170 citations

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

    Meech, K. J., 2005, Sci

    167 citations

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

    Robinson, Tyler D., 2011, AsBio

    164 citations

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

    Mumma, Michael J., 2005, Sci

    146 citations

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

    Küppers, Michael, 2005, Natur

    132 citations

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

    Thomas, P. C., 2013, Icar

    124 citations

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

    Kelley, Michael S., 2013, Icar

    124 citations

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

    Thomas, Peter C., 2007, Icar

    123 citations

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

    Groussin, O., 2007, Icar

    121 citations

  20. Lunar soil hydration constrained by exospheric water liberated by meteoroid impacts

    Benna, M., 2019, NatGe

    115 citations

How we found these papers

We searched NASA’s Astrophysics Data System (ADS) 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. SciX is ADS’s current interface.

(((=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 "AIASJ" OR "AeAm" OR "AirSp" OR "AsNow" OR "AsUAI" OR "AvWST" OR "C&E" OR "C&T" OR "CAPJ" OR "E&S" OR "ENews" OR "IrAJ" OR "JCos" OR "JRASC" OR "LAstr" OR "MNSSA" OR "Met" OR "NewSc" OR "Orion" OR "PhT" OR "PhTea" OR "PhuZ" OR "PhyOJ" OR "PhyW" OR "PlR" OR "SciAm" OR "SpFl" 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 incidental: Nature news article by a staff journalist (Peplow, "Deep Impact: sifting through the debris"); reports the mission, presents no result. News articles are excluded as a general rule (owner decision 2026-09-07). 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 🤖