Dimorphos

{{Infobox planet

| name = Dimorphos

| image = Dimorphos North-Up Image Composition (final 10 full-frame images).png

| image_scale =

| caption = High-resolution view of Dimorphos, created by combining the final 10 full-frame images obtained by DART's Didymos Reconnaissance and Asteroid Camera for Optical navigation (DRACO). Dimorphos is oriented so that its north pole is toward the top of the image. Taken seconds before impact on September 26, 2022.

| discovery_ref =

| discoverer = Petr Pravec et al.{{efn|

Astronomers involved in the discovery of Dimorphos include P. Pravec, L.A.M. Benner, M.C. Nolan, P. Kusnirak, D. Pray, J.D. Giorgini, R.F. Jurgens, S.J. Ostro, J.-L. Margot, C. Magri, A. Grauer, and S. Larson. The discovery used lightcurve and radar observations from the Jet Propulsion Laboratory, Pasadena, CA; National Astronomy and Ionosphere Center / Arecibo Observatory, Arecibo, PR; and Ondrejov Observatory, Ondřejov, CZ. }}

| discovery_site = Ondřejov Observatory

| discovered = 20 November 2003

| mpc_name = Didymos I

| alt_names = S/2003 (65803) 1
Didymos B
"Didymoon"

| pronounced = {{IPAc-en|d|aɪ|'|m|ɔːr|f|ə|s}} {{respell|dy|MOR|fəs}}

| named_after = Greek word for "having two forms"

| satellite_of = 65803 Didymos

| orbit_ref = {{rp|pages=28}}

| epoch = 26 September 2022 23:14:24.183 UTC
(JD {{val|2459849.4683355}}; impact time){{rp|pages=5}}{{rp|pages=28}}

| semimajor = {{val|1.206|0.035|u=km}} (pre-impact){{rp|pages=28}}
{{val|1.144|0.070|u=km}} (post-impact){{rp|page=5}}

| eccentricity = {{val|0|p=≈}} (pre-impact){{rp|page=15}}
{{val|0.021|0.014}} or {{val|0.0247|0.0002}}{{rp|page=16}} (post-impact)

| period = {{val|11.921473|0.000044|u=hr}}
{{nowrap|(11h 55m 17.3s ± 0.2s; pre-impact)}}{{rp|pages=28}}
{{val|11.3676|0.0014|u=hr}}
{{nowrap|(11h 22m 03.4s ± 5.0s; post-impact)}}

| avg_speed = {{val|0.177|u=m/s}} (pre-impact){{efn|name=orbitspeed}}

| inclination = {{val|169.3|1.0|u=°}} with respect to ecliptic{{efn|name=pole|Thomas et al. (2023) give Dimorphos's orbit pole orientation in terms of ecliptic coordinates, where {{mvar|λ}} is ecliptic longitude and {{mvar|β}} is ecliptic latitude.{{rp|pages=28}} {{mvar|β}} is the angular offset from the ecliptic plane, whereas inclination {{mvar|i}} with respect to the ecliptic is the angular offset of the orbital pole from the ecliptic north pole, at {{nobr| {{mvar|β}} {{=}} +90° ;}} {{mvar|i}} with respect to the ecliptic would be the complement of {{mvar|β}}. Therefore, given {{nobr| {{mvar|β}} {{=}} –79.3° ,}} {{nobr| {{mvar|i}} {{=}} 90° – (–79.3°) {{=}} 169.3° }} from the ecliptic.}}

| physical_ref = {{rp|page=9}}

| dimensions = {{val|177|x|174|x|116}} m (± {{val|2|x|4|x|2}} m)

| mean_diameter = {{val|151|5|u=m}} (volume equivalent)

| surface_area = {{val|7.58|e=4|u=m2}}

| volume = {{val|1.81|0.18|e=6|u=m3}}

| mass = {{val|1.33|0.30|e=9|u=kg}} (if density is {{val|0.6|-|0.7|u=g/cm3}})
≈ {{val|4.3|e=9|u=kg}} (if same density as Didymos){{rp|page=9}}

| density = {{val|0.6|-|0.7|u=g/cm3}}
{{val|2.4|0.9|u=g/cm3}} (if same as Didymos){{rp|pages=29}}

| rotation = ≈ {{val|11.9|u=hr}} (synchronous; pre-impact)
chaotic (post-impact)

| albedo = {{val|0.15|0.02}}{{rp|page=6}}

| spectral_type = S

| abs_magnitude = {{val|21.4|0.2}}{{efn|name=magdiff|Absolute magnitude of Dimorphos calculated from the addition of its magnitude difference to Didymos's absolute magnitude: 18.07 + 3.29 ≈ 21.4.}}

}}

Dimorphos (formal designation (65803) Didymos I; provisional designation S/2003 (65803) 1) is a natural satellite or moon of the near-Earth asteroid 65803 Didymos, with which it forms a binary system. The moon was discovered on 20 November 2003 by Petr Pravec in collaboration with other astronomers worldwide. Dimorphos has a diameter of {{convert|177|m|ft|sp=us}} across its longest extent and it was the target of the Double Asteroid Redirection Test (DART), a NASA space mission that deliberately collided a spacecraft with the moon on 26 September 2022 to alter its orbit around Didymos. Before the impact by DART, Dimorphos had a shape of an oblate spheroid with a surface covered in boulders but virtually no craters. The moon is thought to have formed when Didymos shed its mass due to its rapid rotation, which formed an orbiting ring of debris that conglomerated into a low-density rubble pile that became Dimorphos today.

The DART impact reduced Dimorphos's orbital period around Didymos by 33 minutes and ejected over {{convert|1|e6kg|e6lbs}} of debris into space, producing a dust plume that temporarily brightened the Didymos system and developed a {{convert|10000|km|mi|adj=on|sp=us}}-long dust tail that persisted for several months. The DART impact is predicted to have caused global resurfacing and deformation of Dimorphos's shape, leaving an impact crater several tens of meters in diameter. Post-impact observations of brightness fluctuations within the Didymos system suggest that the impact may have either significantly deformed Dimorphos into an ellipsoidal shape or may have sent it into a chaotically tumbling rotation. If Dimorphos was in a tumbling rotation state, the moon will be subjected to irregular tidal forces by Didymos before it will eventually return to a tidally locked state within several decades. The ESA mission Hera is planned to arrive at the Didymos system in 2026 to further study the effects of DART's impact on Dimorphos.

Discovery

File:Didymos-Arecibo-radar-images.png in 2003]]

The primary asteroid Didymos was discovered in 1996 by Joe Montani of the Spacewatch Project at the University of Arizona. The satellite Dimorphos was discovered on 20 November 2003, in photometric observations by Petr Pravec and colleagues at the Ondřejov Observatory in the Czech Republic. Dimorphos was detected through periodic dips in Didymos's brightness due to mutual eclipses and occultations. With his collaborators, he confirmed from the Arecibo radar delay-Doppler images that Didymos is a binary system.{{cite report |last1=Pravec |first1=P. |last2=Benner |first2=L.A.M. |last3=Nolan|first3=M.C. |last4=Kusnirak |first4=P. |last5=Pray |first5=D. |last6=Giorgini |first6=J. D.|last7=Jurgens |first7=R.F. |last8=Ostro |first8=S.J. |last9=Margot |first9=J.-L. |last10=Magri |first10=C. |last11=Grauer |first11=A. |year=2003 |title={{nobr|(65803) 1996 GT}} |lang=en |series=IAU Circular |volume=8244 |page=2 |bibcode=2003IAUC.8244....2P |publisher=International Astronomical Union / Central Bureau for Astronomical Telegrams |place=Cambridge, MA |via=Harvard U. |url=https://ui.adsabs.harvard.edu/abs/2003IAUC.8244....2P/abstract}}

Etymology

The Working Group for Small Bodies Nomenclature of the International Astronomical Union (IAU) gave the satellite its official name on 23 June 2020.{{cite news |last=Temming |first=Maria |date=29 June 2020 |title=An asteroid's moon got a name so NASA can bump it off its course |website=Science News |url=https://www.sciencenews.org/article/asteroid-moon-name-nasa-course-deflection-mission |access-date=1 July 2020}} The name Dimorphos is derived from a Greek word ({{lang|grc|Δίμορφος}}) meaning 'having two forms'.{{cite web |title=MPEC 2020-M83 |website=minorplanetcenter.net |publisher=Minor Planet Center |place=Cambridge, MA |url=https://minorplanetcenter.net/mpec/K20/K20M83.html |access-date=2020-07-01}}{{LSJ|di/morfos|{{math|δίμορφος}}|ref}}{{efn|The name Dimorphos was suggested by planetary scientist Kleomenis Tsiganis at the Aristotle University of Thessaloniki. Tsiganis explained that the name "has been chosen in anticipation of its changes: It will be known to us in two very different forms, the one seen by DART before the impact, and the other seen by Hera a few years later."{{cite press release |publisher=International Astronomical Union |date=23 June 2020 |title=IAU approves name of target of first NASA and ESA planetary defence missions |website=iau.org |url=https://www.iau.org/news/pressreleases/detail/iau2007/ |access-date=2020-07-01}}}} The justification for the new name reads: "As the target of the DART and Hera space missions, it will become the first celestial body in cosmic history whose form was substantially changed as a result of human intervention (the DART impact)". The name was suggested by Kleomenis Tsiganis, a planetary scientist at the Aristotle University of Thessaloniki and a member of both the DART and Hera teams. Prior to the IAU naming, the nickname Didymoon was used in official communications.{{cite web |title=Target: Didymoon |date=2015-03-31 |website=esa.int |publisher=European Space Agency |url=https://www.esa.int/ESA_Multimedia/Images/2015/03/Target_Didymoon |access-date=2021-11-24}}

Exploration

On 24 November 2021, NASA and the Applied Physics Laboratory launched an impactor spacecraft towards Dimorphos as part of their Double Asteroid Redirection Test (DART).{{cite news |last=Greshko |first=Michael |date=2021-11-23 |title=This NASA spacecraft will smash into an asteroid – to practice saving Earth |website=National Geographic |lang=en |url=https://www.nationalgeographic.com/science/article/nasas-dart-spacecraft-will-smash-into-an-asteroid-to-practice-saving-earth |url-status=dead |access-date=2021-11-25 |archive-url=https://web.archive.org/web/20211123113703/https://www.nationalgeographic.com/science/article/nasas-dart-spacecraft-will-smash-into-an-asteroid-to-practice-saving-earth |archive-date=2021-11-23 }}{{cite press release |last=Potter |first=Sean |date=2021-11-23 |title=NASA, SpaceX Launch DART: First test mission to defend planet Earth |website=NASA |url=http://www.nasa.gov/press-release/nasa-spacex-launch-dart-first-test-mission-to-defend-planet-earth |access-date=2021-11-25}} DART was the first experiment conducted in space to test asteroid deflection as a method of defending Earth from potentially hazardous asteroids.{{cite news |last=Rincon |first=Paul |date=2021-11-24 |title=NASA DART asteroid spacecraft: Mission to smash into Dimorphos space rock launches |lang=en-GB |website=BBC News |url=https://www.bbc.com/news/science-environment-59327293|access-date=2021-11-25}} Following a ten-month journey to the Didymos system, the impactor collided with Dimorphos on 26 September 2022 at a speed of around {{Convert|15000|mph|km/h|abbr=off|order=flip|sp=us}}.{{cite press release |last=Potter |first=Sean |date=2021-11-23 |title=NASA, SpaceX Launch DART: First test mission to defend planet Earth |website=NASA |publisher=National Aeronautics and Space Administration |url=http://www.nasa.gov/press-release/nasa-spacex-launch-dart-first-test-mission-to-defend-planet-earth |access-date=2021-11-25}} The collision successfully decreased Dimorphos's orbital period around Didymos by {{val|32|2}} minutes.{{cite web |title=NASA Confirms DART Mission Impact Changed Asteroid's Motion in Space |url=https://www.nasa.gov/press-release/nasa-confirms-dart-mission-impact-changed-asteroid-s-motion-in-space |last=Dunbar |first=Brian |website=NASA |date=11 October 2022 |access-date=2022-10-11 |language=en}}{{cite magazine |last=Crane |first=Leah |date=2021-11-23 |title=NASA's DART mission will try to deflect an asteroid by flying into it |magazine=New Scientist |lang=en-UK |url=https://www.newscientist.com/article/2298530-nasas-dart-mission-will-try-to-deflect-an-asteroid-by-flying-into-it/ |url-status=live |access-date=2021-11-25 |archive-url=https://web.archive.org/web/20211123132010/https://www.newscientist.com/article/2298530-nasas-dart-mission-will-try-to-deflect-an-asteroid-by-flying-into-it/ |archive-date=2021-11-23 }}{{cite web |last1=Nelson |first1=Bill |last2=Saccoccia |first2=Giorgio |title=Update on DART Mission to Asteroid Dimorphos (NASA News Conference) |url=https://www.youtube.com/watch?v=Zhzn0U2m5wQ |website=YouTube |date=11 October 2022 |access-date=2022-10-11 |language=en}} Fifteen days prior to its collision, the impactor released LICIACube, an Italian Space Agency CubeSat that photographed the impact and the resulting dust plume as it performed a close flyby of the Didymos system.{{cite press release |title=DART's small satellite companion tests camera prior to Dimorphos impact |website=NASA.gov |publisher=National Aeronautics and Space Administration |url=https://www.nasa.gov/feature/dart-s-small-satellite-companion-tests-camera-prior-to-dimorphos-impact |access-date=25 September 2022}} Spacecraft and observatories such as Hubble, James Webb, Lucy, SAAO and ATLAS also captured the dust plume trailing the Didymos system in the days following the impact.{{cite news|url=https://gizmodo.com/telescopes-capture-dart-asteroid-impact-1849585394|title=Ground Telescopes Capture Jaw-Dropping Views of DART Asteroid Impact|quote=Telescopes around the world honed in on the historic collision, revealing a surprisingly large and bright impact plume.|author=George Dvorsky|date=September 27, 2022|publisher=Gizmodo}}{{cite web |title=LICIACube Impact Images |url=https://www.nasa.gov/feature/first-images-from-italian-space-agency-s-liciacube-satellite |website=NASA |date=27 September 2022 |access-date=2 October 2022}} As part of its Hera mission, ESA launched three spacecraft to the Didymos system in 2024 to reach this asteroid system in December 2026 to further study the aftermath of the impact.{{cite journal |last=Witze |first=Alexandra |date=2021-11-19 |title=NASA spacecraft will slam into asteroid in first planetary-defence test |lang=en |journal=Nature |volume=600 |issue=7887 |doi=10.1038/d41586-021-03471-w |pages=17–18 |pmid=34799719 |bibcode=2021Natur.600...17W |s2cid=244428237 |doi-access=free }}{{cite journal |last1=Michel |first1=Patrick |last2=Küppers |first2=Michael |last3=Bagatin |first3=Adriano Campo |last4=Carry |first4=Benoit |last5=Charnoz |first5=Sébastien |last6=Leon |first6=Julia de |last7=Fitzsimmons |first7=Alan |last8=Gordo |first8=Paulo |last9=Green |first9=Simon F. |last10=Hérique |first10=Alain |last11=Juzi |first11=Martin |last12=Karatekin |first12=Özgür |last13=Kohout |first13=Tomas |last14=Lazzarin |first14=Monica |last15=Murdoch |first15=Naomi |last16=Okada |first16=Tatsuaki |last17=Palomba |first17=Ernesto |last18=Pravec |first18=Petr |last19=Snodgrass |first19=Colin |last20=Tortora |first20=Paolo |last21=Tsiganis |first21=Kleomenis |last22=Ulamec |first22=Stephan |last23=Vincent |first23=Jean-Baptiste |last24=Wünnemann |first24=Kai |last25=Zhang |first25=Yun |last26=Raducan |first26=Sabina D. |last27=Dotto |first27=Elisabetta |last28=Chabot |first28=Nancy |last29=Cheng |first29=Andy F. |last30=Rivkin |first30=Andy |last31=Barnouin |first31=Olivier |last32=Ernst |first32=Carolyn |last33=Stickle |first33=Angela |last34=Richardson |first34=Derek C. |last35=Thomas |first35=Cristina |last36=Arakawa |first36=Masahiko |last37=Miyamoto |first37=Hirdy |last38=Nakamura |first38=Akiko |last39=Sugita |first39=Seiji |last40=Yoshikawa |first40=Makoto |last41=Abell |first41=Paul |last42=Asphaug |first42=Erik |last43=Ballouz |first43=Ronald-Louis |last44=Bottke |first44=William F. |last45=Lauretta |first45=Dante S. |last46=Walsh |first46=Kevin J. |last47=Martino |first47=Paolo |last48=Carnelli |first48=Ian |display-authors=1| title=The ESA Hera Mission: Detailed Characterization of the DART Impact Outcome and of the Binary Asteroid (65803) Didymos |journal=The Planetary Science Journal |date=1 July 2022 |volume=3 |issue=7 |pages=160 |doi=10.3847/psj/ac6f52 |bibcode=2022PSJ.....3..160M |s2cid=250599919 |language=en |issn=2632-3338|doi-access=free |hdl=10045/125568 |hdl-access=free }}

File:Hubble sees boulders escaping from asteroid Dimorphos (heic2307a).jpg photo taken about three months after the collision. The asteroid is surrounded by blue dots, which are boulders ranging from 1 to 6.7 metres across that were ejected by the impact.]]

The DART impact on the center of Dimorphos decreased the orbital period, previously 11.92 hours, by 33±1 minutes. This large change indicates the recoil from material excavated from the asteroid and ejected into space by the impact (known as ejecta) contributed significant momentum change to the asteroid, beyond that of the DART spacecraft itself. Researchers found the impact caused an instantaneous slowing in Dimorphos' speed along its orbit of about 2.7 millimeters per second — again indicating the recoil from ejecta played a major role in amplifying the momentum change directly imparted to the asteroid by the spacecraft. That momentum change was amplified by a factor of 2.2 to 4.9 (depending on the mass of Dimorphos), indicating the momentum change transferred because of ejecta production significantly exceeded the momentum change from the DART spacecraft alone.{{cite web |last1=Furfaro |first1=Emily |title=NASA's DART Data Validates Kinetic Impact as Planetary Defense Method |url=https://www.nasa.gov/feature/nasa-s-dart-data-validates-kinetic-impact-as-planetary-defense-method |website=NASA |access-date=9 March 2023 |date=28 February 2023}} {{PD-notice}} While the orbital change was small, the change is in the velocity and over the course of years will accumulate to a large change in position.{{Cite web |title=NASA Pushes Through With Asteroid Deflection Mission That Could One Day Save Earth – Inquisitr |url=https://www.inquisitr.com/4346664/nasa-dart-asteroid-deflection-mission-save-earth-goes-into-design-phase/ |access-date=27 September 2022 |website=inquisitr.com|date=5 July 2017 }} For a hypothetical Earth-threatening body, even such a tiny change could be sufficient to mitigate or prevent an impact, if applied early enough. As the diameter of Earth is around 13,000 kilometers, a hypothetical asteroid impact could be avoided with as little of a shift as half of that (6,500 kilometers). A {{val|2|u=cm/s}} velocity change accumulates to that distance in approximately 10 years.

File:Two LICIACube LUKE images showing the ejecta morphology that were used to reduce the possible axis orientation solutions.webp

By smashing into the asteroid DART made Dimorphos an active asteroid. Scientists had proposed that some active asteroids are the result of impact events, but no one had ever observed the activation of an asteroid. The DART mission activated Dimorphos under precisely known and carefully observed impact conditions, enabling the detailed study of the formation of an active asteroid for the first time.{{cite journal |last1=Li |first1=Jian-Yang |last2=Hirabayashi |first2=Masatoshi |last3=Farnham |first3=Tony L. |last4=Sunshine |first4=Jessica M. |last5=Knight |first5=Matthew M. |last6=Tancredi |first6=Gonzalo |last7=Moreno |first7=Fernando |last8=Murphy |first8=Brian |last9=Opitom |first9=Cyrielle |last10=Chesley |first10=Steve |last11=Scheeres |first11=Daniel J. |last12=Thomas |first12=Cristina A. |last13=Fahnestock |first13=Eugene G. |last14=Cheng |first14=Andrew F. |last15=Dressel |first15=Linda |last16=Ernst |first16=Carolyn M. |last17=Ferrari |first17=Fabio |last18=Fitzsimmons |first18=Alan |last19=Ieva |first19=Simone |last20=Ivanovski |first20=Stavro L. |last21=Kareta |first21=Teddy |last22=Kolokolova |first22=Ludmilla |last23=Lister |first23=Tim |last24=Raducan |first24=Sabina D. |last25=Rivkin |first25=Andrew S. |last26=Rossi |first26=Alessandro |last27=Soldini |first27=Stefania |last28=Stickle |first28=Angela M. |last29=Vick |first29=Alison |last30=Vincent |first30=Jean-Baptiste |last31=Weaver |first31=Harold A. |last32=Bagnulo |first32=Stefano |last33=Bannister |first33=Michele T. |last34=Cambioni |first34=Saverio |last35=Bagatin |first35=Adriano Campo |last36=Chabot |first36=Nancy L. |last37=Cremonese |first37=Gabriele |last38=Daly |first38=R. Terik |last39=Dotto |first39=Elisabetta |last40=Glenar |first40=David A. |last41=Granvik |first41=Mikael |last42=Hasselmann |first42=Pedro H. |last43=Herreros |first43=Isabel |last44=Jacobson |first44=Seth |last45=Jutzi |first45=Martin |last46=Kohout |first46=Tomas |last47=La Forgia |first47=Fiorangela |last48=Lazzarin |first48=Monica |last49=Lin |first49=Zhong-Yi |last50=Lolachi |first50=Ramin |last51=Lucchetti |first51=Alice |last52=Makadia |first52=Rahil |last53=Epifani |first53=Elena Mazzotta |last54=Michel |first54=Patrick |last55=Migliorini |first55=Alessandra |last56=Moskovitz |first56=Nicholas A. |last57=Ormö |first57=Jens |last58=Pajola |first58=Maurizio |last59=Sánchez |first59=Paul |last60=Schwartz |first60=Stephen R. |last61=Snodgrass |first61=Colin |last62=Steckloff |first62=Jordan |last63=Stubbs |first63=Timothy J. |last64=Trigo-Rodríguez |first64=Josep M. |title=Ejecta from the DART-produced active asteroid Dimorphos |journal=Nature |date=1 March 2023 |volume=616 |issue=7957 |pages=452–456 |doi=10.1038/s41586-023-05811-4 |pmid=36858074 |pmc=10115637 |arxiv=2303.01700 |bibcode=2023Natur.616..452L |language=en |issn=1476-4687 |display-authors=3}} Observations show that Dimorphos lost approximately 1 million kilograms after the collision.{{cite journal |last1=Witze |first1=Alexandra |title=Asteroid lost 1 million kilograms after collision with DART spacecraft |journal=Nature |date=1 March 2023 |volume=615 |issue=7951 |pages=195 |doi=10.1038/d41586-023-00601-4 |pmid=36859675 |bibcode=2023Natur.615..195W |s2cid=257282080 |url=https://www.nature.com/articles/d41586-023-00601-4 |access-date=9 March 2023 |language=en}} Impact produced a dust plume that temporarily brightened the Didymos system and developed a {{convert|10000|km|mi|adj=on|sp=us}}-long dust tail that persisted for several months. The DART impact is predicted to have caused global resurfacing and deformation of Dimorphos's shape, leaving an impact crater several tens of meters in diameter. The impact has likely sent Dimorphos into a chaotically tumbling rotation that will subject the moon to irregular tidal forces by Didymos before it will eventually return to a tidally locked state within several decades. Additionally, the impact changed Dimorphos shape from a roughly symmetrical "oblate spheroid" to "a flat-topped oval", or "triaxial ellipsoid".{{Cite news |last=Andrews |first=Robin George |date=2024-02-26 |title=NASA's Crash Into an Asteroid May Have Altered Its Shape |url=https://www.nytimes.com/2024/02/26/science/nasa-crash-asteroid-dart-study.html |access-date=2024-02-28 |work=The New York Times |language=en-US |issn=0362-4331}}{{cite web |title=NASA Study: Asteroid's Orbit, Shape Changed After DART Impact |url=https://www.jpl.nasa.gov/news/nasa-study-asteroids-orbit-shape-changed-after-dart-impact |website=NASA Jet Propulsion Laboratory (JPL) |access-date=22 May 2024}}{{cite journal |last1=Naidu |first1=Shantanu P. |last2=Chesley |first2=Steven R. |last3=Moskovitz |first3=Nicholas |last4=Thomas |first4=Cristina |last5=Meyer |first5=Alex J. |last6=Pravec |first6=Petr |last7=Scheirich |first7=Peter |last8=Farnocchia |first8=Davide |last9=Scheeres |first9=Daniel J. |last10=Brozovic |first10=Marina |last11=Benner |first11=Lance A. M. |last12=Rivkin |first12=Andrew S. |last13=Chabot |first13=Nancy L. |title=Orbital and Physical Characterization of Asteroid Dimorphos Following the DART Impact |journal=The Planetary Science Journal |date=1 March 2024 |volume=5 |issue=3 |pages=74 |doi=10.3847/PSJ/ad26e7|doi-access=free |bibcode=2024PSJ.....5...74N }}

Size and shape

Dimorphos is approximately {{convert|170|m|sp=us}} in diameter, compared to Didymos at {{convert|780|m|sp=us}}. Dimorphos does not have a confirmed mass, but it is estimated to be about {{val|5|e=9|u=kg}} (5.5 million tons), or about the same mass and size as the Great Pyramid of Giza, when assuming a density of {{val|2.17|u=g/cm3}} similar to Didymos.{{Cite journal |last1=Nakano |first1=Ryota |last2=Hirabayashi |first2=Masatoshi |last3=Agrusa |first3=Harrison F. |last4=Ferrari |first4=Fabio |last5=Meyer |first5=Alex J. |last6=Michel |first6=Patrick |last7=Raducan |first7=Sabina D. |last8=Sánchez |first8=Paul |last9=Zhang |first9=Yun |date=2022-07-01 |title=NASA's Double Asteroid Redirection Test (DART): Mutual Orbital Period Change Due to Reshaping in the Near-Earth Binary Asteroid System (65803) Didymos |journal=The Planetary Science Journal |volume=3 |issue=7 |pages=148 |doi=10.3847/PSJ/ac7566 |bibcode=2022PSJ.....3..148N |s2cid=250327233 |issn=2632-3338|doi-access=free }} It is one of the smallest celestial objects given a formal name by the IAU, after 367943 Duende and 469219 Kamoʻoalewa.

The final few minutes of pictures from the DART mission revealed an egg-shaped body covered with boulders, suggesting it has a rubble pile structure.{{cite web |title=NASA crashes DART spacecraft into asteroid in world's 1st planetary defense test |author=Tariq Malik |url=https://www.space.com/nasa-dart-asteroid-impact-planetary-defense-success |work=Space.com |date=2022-09-26}}

Surface

Five boulders (saxa) and six craters have been given names of traditional drums from several cultures. They are approximately 10 meters across or smaller:{{Cite web|url=https://planetarynames.wr.usgs.gov/SearchResults?Target=155_Dimorphos|title=Planetary Names|website=planetarynames.wr.usgs.gov}}

Name ! Pronunciation	Feature	Named after	Date approved
class="wikitable" style="margin-left: auto; margin-right: auto; border: none;" \|+Named features
Atabaque Saxum \| {{IPAc-en\|UK\|ˌ\|ae\|t\|@\|'\|b\|ae\|k\|i}} {{respell\|AT\|ə\|BAK\|ee}} {{IPAc-en\|US\|ˌ\|A:\|t\|@\|'\|b\|A:\|k\|i}} {{respell\|AH\|tə\|BAH\|kee}}	boulder	atabaque (Brazil)	25 Jan 2023
Bodhran Saxum \| {{IPAc-en\|ˈ\|b\|ɔ:\|r\|ɑ:\|n}} {{respell\|BOR\|ahn}}	boulder	bodhrán (Ireland)	25 Jan 2023
Caccavella Saxum \| {{IPAc-en\|ˌ\|k\|ae\|k\|@\|'\|v\|E\|l\|@}} {{respell\|KAK\|ə\|VEL\|ə}}	boulder	caccavella a.k.a. putipù (Italy)	25 Jan 2023
Dhol Saxum \| {{IPAc-en\|'\|d\|O:\|l}} {{respell\|DAWL}}	boulder	dhol (India)	25 Jan 2023
Pūniu Saxum \| {{IPAc-en\|'\|p\|u:\|n\|i\|.\|u:}} {{respell\|POO\|nee\|oo}}	boulder	pūniu a.k.a. kilu (Hawaii)	25 Jan 2023
Bala Crater \| {{IPAc-en\|'\|b\|ae\|l\|@}} {{respell\|BAL\|ə}}	crater	balafon (Guinea, Senegal, Mali)	14 Nov 2023
Bongo Crater \| {{IPAc-en\|'\|b\|Q\|N\|g\|ou}} {{respell\|BONG\|goh}}	crater	bongo (Cuba)	14 Nov 2023
Marimba Crater \| {{IPAc-en\|m\|@\|'\|r\|I\|m\|b\|@}} {{respell\|mə\|RIM\|bə}}	crater	marimba (Central America)	14 Nov 2023
Msondo Crater \| {{IPAc-en\|E\|m\|'\|s\|Q\|n\|d\|ou}} {{respell\|em\|SON\|doh}}	crater	msondo (Tanzania)	14 Nov 2023
Naqqara Crater \| {{IPAc-en\|n\|ae\|'\|k\|a:r\|@}} {{respell\|na\|KAR\|ə}}	crater	naqqara (naker) (Mid East and India)	14 Nov 2023
Tamboril Crater \| {{IPAc-en\|ˌ\|t\|ae\|m\|b\|@\|'\|r\|I\|l}} {{respell\|TAM\|bər\|IL}}	crater	tamboril (Uruguay, Candombe)	14 Nov 2023

{{multiple image

| total_width = 600

| align =center

| image1 = Penultimate image of Dimorphos by DART.png

| image2 = Dimorphos North-Up Image Composition with Named Features (final 10 full-frame images).png

| footer = Left: Surface of Dimorphos, captured by DART two seconds before impact. Right: Composite map of Dimorphos with named features.

}}

Orbit and rotation

File:Animation of DART around Didymos - Impact on Dimorphos.gif

The primary body of the binary system, Didymos, orbits the Sun at a distance of 1.0 to 2.3 AU once every 770 days (2 years and 1 month). The pathway of the orbit has an eccentricity of 0.38 and an inclination of 3° with respect to the ecliptic. On 4 October 2022 Didymos made an Earth approach of {{convert|10.6|e6km|e6mi|abbr=unit}}.{{cite report |title=65803 Didymos |series=JPL Small-Body Database Browser |publisher=NASA / Jet Propulsion Laboratory |url=https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=2065803&view=OPC |access-date=2021-12-30 |via=ssd.jpl.nasa.gov}} Dimorphos moves in a nearly equatorial, nearly circular orbit around Didymos, with an orbital period of 11.9 hours. Its orbit period is synchronous with its rotation, so that the same side of Dimorphos always faces Didymos. Dimorphos's orbit is retrograde relative to the ecliptic plane, in conformity with Didymos's retrograde rotation.{{cite journal |last1=Scheirich |first1=P. |last2=Pravec |first2=P. |last3=Jacobson |first3=S.A. |last4=Ďurech |first4=J. |last5=Kušnirák |first5=P. |last6=Hornoch |first6=K.|last7=Mottola |first7=S. |last8=Mommert |first8=M. |last9=Hellmich |first9=S. |last10=Pray |first10=D. |last11=Polishook |first11=D. |first12=Yu.N. |last12=Krugly |last13=Inasaridze |first13=R.Ya. |last14=Kvaratskhelia |first14=O.I. |last15=Ayvazian |first15=V. |last16=Slyusarev |first16=I. |last17=Pittichová |first17=J. |last18=Jehin |first18=E. |last19=Manfroid |first19=J. |last20=Gillon |first20=M. |last21=Galád |first21=A. |last22=Pollock |first22=J. |last23=Licandro |first23=J. |last24=Alí-Lagoa |first24=V. |last25=Brinsfield |first25=J. |last26=Molotov |first26=I.E. |display-authors=6 |year=2015 |title=The binary near-Earth asteroid {{nobr|(175706) 1996 FG3}} – an observational constraint on its orbital evolution |journal=Icarus |volume=245 |pages=56–63 |arxiv=1406.4677 |bibcode=2015Icar..245...56S |doi=10.1016/j.icarus.2014.09.023 |s2cid=119248574}}

Dimorphos's rotation is being slowed down by the YORP effect, with an estimated rotation period doubling time of 86,000 years. However, because it is in orbit around Didymos, tidal forces keep the moon locked in synchronous rotation.

Footnotes

{{notelist|notes=

{{efn|name=orbitspeed|For a circular orbit with negligible eccentricity, as in the case of Dimorphos, the mean orbital speed can be approximated by the time {{mvar|T}} it takes to complete one revolution around its orbital circumference, with the radius being its semi-major axis {{mvar|a}}: $v = {2 \pi a \over T}$ .}}

}}

References

{{reflist|25em|refs=

{{cite web

|title = Coordinate transformations

|url = https://aas.aanda.org/articles/aas/full/1998/01/ds1449/node3.html

|work = Astronomy and Astrophysics

|publisher = European Southern Observatory

|date = January 1998

|accessdate = 17 June 2022

|archive-date = 17 June 2021

|archive-url = https://web.archive.org/web/20210617050235/https://aas.aanda.org/articles/aas/full/1998/01/ds1449/node3.html

|url-status = live}}

{{cite web

|title = Ellipsoid semi-axis lengths 88.5 87.0 58.0

|url = https://www.wolframalpha.com/input?i=ellipsoid+semi-axis+lengths+88.5+87.0+58.0

|work = Wolfram Alpha

|date = 5 February 2023}}

{{cite journal

|display-authors = etal

|first1 = S. P. |last1 = Naidu

|first2 = L. A. M. |last2 = Benner

|first3 = M. |last3 = Brozovic

|first4 = M. C. |last4 = Nolan

|first5 = S. J. |last5 = Ostro

|first6 = J. L. |last6 = Margot

|title = Radar observations and a physical model of binary near-Earth asteroid 65803 Didymos, target of the DART mission

|url = https://echo.jpl.nasa.gov/asteroids/naidu.etal.2020.didymos.pdf

|journal = Icarus

|date = September 2020

|volume = 348

|id = 134777

|pages = 19

|doi = 10.1016/j.icarus.2020.113777

|bibcode = 2020Icar..34813777N

|s2cid = 219091858}}

{{cite news

|title = Brian May helps show Hera's target asteroid may be 'dust bunny'

|url = https://www.esa.int/Space_Safety/Hera/Brian_May_helps_show_Hera_s_target_asteroid_may_be_dust_bunny

|publisher = European Space Agency

|date = 30 March 2021

|accessdate = 4 February 2023}}

{{cite journal

|display-authors = etal

|first1 = Yun |last1 = Zhang

|first2 = Patrick |last2 = Michel

|first3 = Derek C. |last3 = Richardson

|first4 = Olivier S. |last4 = Barnouin

|first5 = Harrison F. |last5 = Agrusa

|first6 = Kleomenis |last6 = Tsiganis

|title = Creep stability of the DART/Hera mission target 65803 Didymos: II. The role of cohesion

|journal = Icarus

|date = July 2021

|volume = 362

|id = 114433

|pages = 18

|doi-access = free

|doi = 10.1016/j.icarus.2021.114433

|bibcode = 2021Icar..36214433Z

|s2cid = 233701042}}

{{cite web

|title = (65803) Didymos and Dimorphos

|url = http://www.johnstonsarchive.net/astro/astmoons/am-03548.html

|first = Wm. Robert |last = Johnston

|work = Asteroids with Satellites Database

|publisher = Johnston's Archive

|date = 9 October 2021

|accessdate = 11 November 2021}}

{{cite journal

|display-authors = etal

|first1 = Harrison F. |last1 = Agrusa

|first2 = Ioannis |last2 = Gkolias

|first3 = Kleomenis |last3 = Tsiganis

|first4 = Derek C. |last4 = Richardson

|first5 = Alex J. |last5 = Meyer

|first6 = Daniel J. |last6 = Scheeres

|title = The excited spin state of Dimorphos resulting from the DART impact

|journal = Icarus

|date = December 2021

|volume = 370

|id = 114624

|pages = 39

|doi = 10.1016/j.icarus.2021.114624

|arxiv = 2107.07996

|bibcode = 2021Icar..37014624A

|s2cid = 236033921}}

{{cite web

|title = See DART's final images before it smashed into an asteroid

|url = https://www.planetary.org/articles/nasa-dart-final-images-asteroid-crash

|first = Rae |last= Paoletta

|work = The Planetary Society

|date = 26 September 2022

|accessdate = 28 September 2022}}

{{cite journal

|title = Fresh images reveal fireworks when NASA spacecraft plowed into asteroid

|url = https://www.nature.com/articles/d41586-022-03067-y

|first = Alexandra |last= Witze

|journal = Nature

|doi = 10.1038/d41586-022-03067-y

|date = 27 September 2022

|pmid = 36167993

|s2cid = 252566403

|accessdate = 28 September 2022}}

{{cite web

|title = 'Holy $@*%!' Science captures behind-the-scenes reactions to asteroid-smashing mission

|url = https://www.science.org/content/article/holy-science-captures-behind-the-scenes-reactions-asteroid-smashing-mission

|first = Zack |last= Savitsky

|work = Science

|date = 27 September 2022

|accessdate = 28 September 2022}}

{{cite web

|title = Photos Show Drama of DART Asteroid Impact

|url = https://skyandtelescope.org/astronomy-news/photos-show-drama-of-dart-asteroid-impact/

|first = Emily |last= Lakdawalla

|work = Sky & Telescope

|date = 27 September 2022

|accessdate = 28 September 2022}}

{{cite journal

|first1 = Sabina D. |last1 = Raducan

|first2 = Jutzi |last2 = Martin

|title = Global-scale Reshaping and Resurfacing of Asteroids by Small-scale Impacts, with Applications to the DART and Hera Missions

|journal = The Planetary Science Journal

|date = July 2022

|volume = 3

|issue = 6

|id = 128

|pages = 15

|doi-access = free

|doi = 10.3847/PSJ/ac67a7

|bibcode = 2022PSJ.....3..128R

|s2cid = 249268810}}

{{cite journal

|display-authors = etal

|first1 = Ryota |last1 = Nakano

|first2 = Masatoshi |last2 = Hirabayashi

|first3 = M. |last3 = Brozovic

|first4 = M. C. |last4 = Nolan

|first5 = S. J. |last5 = Ostro

|first6 = J. L. |last6 = Margot

|title = NASA's Double Asteroid Redirection Test (DART): Mutual Orbital Period Change Due to Reshaping in the Near-Earth Binary Asteroid System (65803) Didymos

|journal = The Planetary Science Journal

|date = July 2022

|volume = 3

|issue = 7

|id = 148

|pages = 16

|doi-access = free

|doi = 10.3847/PSJ/ac7566

|bibcode = 2022PSJ.....3..148N

|s2cid = 250327233|hdl = 11311/1223308

|hdl-access = free

}}

{{cite journal

|display-authors = etal

|first1 = Derek C. |last1 = Richardson

|first2 = Harrison F. |last2 = Agrusa

|first3 = Brent |last3 = Barbee

|first4 = William F.|last4 = Bottke

|first5 = Andrew F. |last5 = Cheng

|first6 = Siegfried |last6 = Eggl

|title = Predictions for the Dynamical States of the Didymos System before and after the Planned DART Impact

|journal = The Planetary Science Journal

|date = July 2022

|volume = 3

|issue = 7

|id = 157

|pages = 23

|doi-access = free

|doi = 10.3847/PSJ/ac76c9

|arxiv = 2207.06998

|bibcode = 2022PSJ.....3..157R

|s2cid = 249268465}}

{{cite web

|title = SOAR Telescope Catches Dimorphos's Expanding Comet-like Tail After DART Impact

|url = https://noirlab.edu/public/news/noirlab2223/

|first = Charles |last= Blue

|publisher = NOIRLab

|date = 3 October 2022

|accessdate = 4 February 2023}}

{{cite web

|title = Early Results from NASA's DART Mission

|url = https://www.nasa.gov/feature/early-results-from-nasa-s-dart-mission

|first = Jessica |last= Merzdorf

|publisher = NASA

|date = 15 December 2022

|accessdate = 4 February 2023}}

{{cite conference

|display-authors = etal

|first1 = O. S. |last1 = Barnouin

|first2 = R. L. |last2 = Ballouz

|first3 = S. |last3 = Marchi

|first4 = J.-B. |last4 = Vincent

|first5 = M. |last5 = Pajola

|first6 = A. |last6 = Lucchetti

|title = The Geology of the Didymos System

|url = https://www.hou.usra.edu/meetings/lpsc2023/pdf/2605.pdf

|conference = 54th Lunar and Planetary Science Conference 2023

|publisher = Lunar and Planetary Institute

|date = March 2023

|issue = 2605

|accessdate = 4 February 2023}}

{{cite conference

|display-authors = etal

|first1 = S. D. |last1 = Raducan

|first2 = M. |last2 = Jutzi

|first3 = Y. |last3 = Zhang

|first4 = A. F. |last4 = Cheng

|first5 = G. S. |last5 = Collins

|first6 = T. M. |last6 = Davison

|title =Low Strength of Asteroid Dimorphos As Demonstrated by the Dart Impact

|url = https://www.hou.usra.edu/meetings/lpsc2023/pdf/2033.pdf

|conference = 54th Lunar and Planetary Science Conference 2023

|publisher = Lunar and Planetary Institute

|date = March 2023

|issue = 2033

|accessdate = 4 February 2023}}

{{cite conference

|display-authors = etal

|first1 = A. J. |last1 = Meyer

|first2 = G. |last2 = Noiset

|first3 = Ö. |last3 = Karatekin

|first4 = J. |last4 = McMahon

|first5 = H. F. |last5 = Agrusa

|first6 = R. |last6 = Nakano

|title = Tidal Dissipation in Didymos Following the DART Impact

|url = https://www.hou.usra.edu/meetings/lpsc2023/pdf/2105.pdf

|conference = 54th Lunar and Planetary Science Conference 2023

|publisher = Lunar and Planetary Institute

|date = March 2023

|issue = 2105

|accessdate = 4 February 2023}}

{{cite conference

|first1 = K. R. |last1 = Ramsley

|first2 = J. W. |last2 = Head

|title = DART Impact: Setting Constraints Using the Tsiolkovsky Rocket Equation

|url = https://www.hou.usra.edu/meetings/lpsc2023/pdf/1079.pdf

|conference = 54th Lunar and Planetary Science Conference 2023

|publisher = Lunar and Planetary Institute

|date = March 2023

|issue = 1709

|accessdate = 4 February 2023}}

{{cite conference

|display-authors = etal

|first1 = M. |last1 = Kanamaru

|first2 = G. |last2 = Tommei

|first3 = T. |last3 = Okada

|first4 = N. |last4 = Sakatani

|first5 = Y. |last5 = Shimaki

|first6 = S. |last6 = Tanaka

|title = Thermophysical Model Development To Simulate Non-Gravitational Acceleration on Binary Asteroid

|url = https://www.hou.usra.edu/meetings/lpsc2023/pdf/2949.pdf

|conference = 54th Lunar and Planetary Science Conference 2023

|publisher = Lunar and Planetary Institute

|date = March 2023

|issue = 2949

|accessdate = 4 February 2023}}

{{cite journal

|first1 = Gustavo |last1 = Madeira

|first2 = Sébastien |last2 = Charnoz

|first3 = Ryuki |last3 = Hyodo

|title = Dynamical origin of Dimorphos from fast spinning Didymos

|journal = Icarus

|date = April 2023

|volume = 394

|id = 115428

|pages = 16

|doi = 10.1016/j.icarus.2023.115428

|arxiv = 2301.02121

|bibcode = 2023Icar..39415428M

|s2cid = 255440287}}

{{cite journal

|display-authors = etal

|first1 = Andrew |last1 = Cheng

|first2 = Harrison |last2 = Agrusa

|first3 = Brent |last3 = Barbee

|first4 = Alex |last4 = Meyer

|first5 = Tony |last5 = Farnham

|first6 = Sabina |last6 = Raducan

|title = Momentum Transfer from the DART Mission Kinetic Impact on Asteroid Dimorphos

|url = https://assets.researchsquare.com/files/rs-2339073/v1_covered.pdf?c=1670565284

|journal = Nature

|date = March 2023

|volume = 616 |issue = 7957 |pages = 457–460 |doi = 10.1038/s41586-023-05878-z

|pmid = 36858075 |pmc = 10115652 |arxiv = 2303.03464

|bibcode = 2023Natur.616..457C}}

{{cite journal

|display-authors = etal

|first1 = R. Terik |last1 = Daly

|first2 = Carolyn M. |last2 = Ernst

|first3 = Olivier S. |last3 = Barnouin

|first4 = Nancy L. |last4 = Chabot

|first5 = Andrew S. |last5 = Rivkin

|first6 = Andrew F. |last6 = Cheng

|title = Successful Kinetic Impact into an Asteroid for Planetary Defense

|url = https://www.nature.com/articles/s41586-023-05810-5.epdf?sharing_token=jXTdHVlr11N2aOxA24DQBNRgN0jAjWel9jnR3ZoTv0NHE9hcFPwYuoQWDVTaVa0x4GyKs5Owh-6-nPe432v_6KQRKJOCfnGVhme0HLffSgL3Y4QVPuAFf4BXuGPBDV2W114tRBHiXdraz_ZBBmDUEs5-_v7OYz5yMWrK_qElp2xf3UQmYtOkfuB_QsbDFbFt21kVRwCvLCx1MO4n1oK7N2OYDHsJVEQ6POGiA3FiMrD_eHe0KqNxxFwwogC3MnDqAQ66V9YB8R-v2iunQ9cd9Q%3D%3D&tracking_referrer=www.space.com

|journal = Nature

|date = March 2023

|volume = 616 |issue = 7957 |pages = 443–447 |doi = 10.1038/s41586-023-05810-5

|pmid = 36858073 |pmc = 10115643 |arxiv = 2303.02248

|bibcode = 2023Natur.616..443D }}

{{cite journal

|display-authors = etal

|first1 = Jian-Yang

|last1 = Li

|first2 = Masatoshi

|last2 = Hirabayashi

|first3 = Tony

|last3 = Farnham

|first4 = Matthew

|last4 = Knight

|first5 = Gonzalo

|last5 = Tancredi

|first6 = Fernando

|last6 = Moreno

|title = Ejecta from the DART-produced active asteroid Dimorphos

|url = https://assets.researchsquare.com/files/rs-2292349/v1/34562254-db7b-4289-a7ff-238159687528.pdf?c=1669139626

|journal = Nature

|date = March 2023

|volume = 616

|issue = 7957

|pages = 452–456

|doi = 10.1038/s41586-023-05811-4

|pmid = 36858074

|pmc = 10115637

|arxiv = 2303.01700

|bibcode = 2023Natur.616..452L

|access-date = 4 February 2023

|archive-date = 7 March 2023

|archive-url = https://web.archive.org/web/20230307161053/https://assets.researchsquare.com/files/rs-2292349/v1/34562254-db7b-4289-a7ff-238159687528.pdf?c=1669139626

|url-status = dead

}}

{{cite journal

|display-authors = etal

|first1 = Cristina A. |last1 = Thomas

|first2 = Shantanu P. |last2 = Naidu

|first3 = Peter |last3 = Scheirich

|first4 = Nicholas A. |last4 = Moskovitz

|first5 = Petr |last5 = Pravec

|first6 = Steven R. |last6 = Chesley

|title = Orbital Period Change of Dimorphos Due to the DART Kinetic Impact

|url = https://www.nature.com/articles/s41586-023-05805-2.epdf?sharing_token=YRh4Eyy6C_2rY32dpDWMvNRgN0jAjWel9jnR3ZoTv0OS4WTElJ09_qri44_z5vPAUIL35_x93QgSDpbGEI6I_LlAizV8gHKjsImCQvUx_50In4IPkBHazpDPqxuNXD9WyXWinLOOxBZC5G8JwgQfps4vO2hNNkv759PcDRrAPBRopiwNeXeZ7XJI-ROdYjsUimVD-CGdugWclBklYFE7i1qL5SHhTjNywsuBNmZk0DeQv3-zIOCOfCCnmxTq29F4yJEBe_3fWCBg3_2rJxqGCw%3D%3D&tracking_referrer=www.space.com

|journal = Nature

|date = March 2023

|volume = 616 |issue = 7957 |pages = 448–451 |doi = 10.1038/s41586-023-05805-2

|pmid = 36858072 |pmc = 10115635 |arxiv = 2303.02077

|bibcode = 2023Natur.616..448T}}

{{cite conference

|display-authors = etal

|first1 = Shantanu P. |last1 = Naidu

|first2 = Steven R. |last2 = Chesley

|first3 = Nick |last3 = Moskovitz

|first4 = Lance A. M. |last4 = Benner

|first5 = Marina |last5 = Brozovic

|first6 = Petr |last6 = Pravec

|title = Change in the mutual orbit of Dimorphos due to the DART impact

|url = https://az659834.vo.msecnd.net/eventsairwesteuprod/production-atpi-public/fa5dcb20a6424c088ae2cc7b89a60964

|conference = 8th IAA Planetary Defense Conference

|location = Vienna, Austria

|date = 2 April 2023

|pages = 17

|archive-url = https://web.archive.org/web/20230404230925/https://az659834.vo.msecnd.net/eventsairwesteuprod/production-atpi-public/fa5dcb20a6424c088ae2cc7b89a60964

|archive-date = 4 April 2023

|url-status= live}}

{{cite web

|title = Horizons Batch showing Dimorphos orbital elements on epochs 2022-Sep-26 23:15 (pre-impact) to 2022-Sep-26 23:16 (post-impact)

|url = https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%27Dimorphos%27&TABLE_TYPE=%27ELEMENTS%27&START_TIME=%272022-09-26%2023:15%27&STOP_TIME=%272022-09-26%2023:16%27&STEP_SIZE=%271%20minute%27&CENTER=%27@20065803%27&OUT_UNITS=%27KM-D%27

|work = JPL Horizons

|publisher = Jet Propulsion Laboratory

|accessdate = 24 March 2023}}

{{cite conference

|first1 = P. |last1 = Scheirich

|first2 = P. |last2 = Pravec

|title = Post-Impact Mutual Orbit of the Didymos Binary System Derived from Photometry

|url = https://www.hou.usra.edu/meetings/acm2023/pdf/2050.pdf

|conference = Asteroids, Comets, Meteors Conference 2023

|publisher = Lunar and Planetary Institute

|issue = 2851

|date = June 2023}}

{{cite conference

|display-authors = etal

|first1 = P. |last1 = Pravec

|first2 = P. |last2 = Scheirich

|first3 = A. J. |last3 = Meyer

|first4 = H. F. |last4 = Agrusa

|first5 = R. |last5 = Nakano

|first6 = M. |last6 = Hirabayashi

|title = Dimorphos's Post-Impact Lightcurves and Constraints on Its Post-Impact Spin State and Shape

|url = https://www.hou.usra.edu/meetings/acm2023/pdf/2052.pdf

|conference = Asteroids, Comets, Meteors Conference 2023

|publisher = Lunar and Planetary Institute

|issue = 2851

|date = June 2023}}

{{cite arXiv

|display-authors = etal

|first1 = Iosto |last1 = Fodde

|first2 = Jinglang |last2 = Feng

|first3 = Massimiliano |last3 = Vasile

|first4 = Jesús |last4 = Gil-Fernández

|title = Design and Analysis of Robust Ballistic Landings on the Secondary of a Binary Asteroid

|class = astro-ph.IM

|date = October 2023

|eprint = 2310.19844}}

}}

External links

{{commonscatinline}}

Category:Asteroid satellites

Category:Named minor planets

Category:Radar-imaged asteroids

Category:Active asteroids

Category:Astronomical objects discovered in 2003

Category:Minor planets visited by spacecraft

Dimorphos

Discovery

Etymology

Exploration

Size and shape

Surface

Orbit and rotation

See also

Footnotes

References

External links