Template:Short description Template:Use dmy dates {{#invoke:infobox|infoboxTemplate | class = vcard | titleclass = fn org | title = (29075) 1950 DA | image = {{#invoke:InfoboxImage|InfoboxImage|image=1950 DA.png|upright={{#if:||1.1}}|alt=}} | caption = Radar image of Template:Mp taken at Arecibo in March 2001, from a distance of 22 LD or 0.052 AU | headerstyle = {{#if:#FFC2E0|background-color:#FFC2E0|background-color:#E0CCFF}} | labelstyle = max-width:{{#if:||11em}}; | autoheaders = y
| header1 = Discovery<ref name="MPC-object" />
| label2 = Discovered by | data2 = Carl A. Wirtanen | label3 = Discovery site | data3 = Lick Obs. | label4 = Discovery date | data4 = 23 February 1950 | label5 = Template:Longitem | data5 =
| header10 = {{#if:|Designations|Designations}}
| label11 = Template:Longitem | data11 = (29075) 1950 DA | label12 = Pronunciation | data12 = | label13 = Template:Longitem | data13 = | label14 = Template:Longitem | data14 = 1950 DATemplate:·Template:MpTemplate:·Object Wirtanen<ref name="IAUCs_1950" /> | label15 = Template:Longitem | data15 = NEOTemplate:·ApolloTemplate:·PHA<ref name="MPC-object" /><ref name="jpldata" />Template:·risk listed | label16 = Adjectives | data16 = | label17 = Symbol | data17 =
| header20 = Orbital characteristics{{#ifeq:|yes| (barycentric)}}<ref name="jpldata" />
| data21 = | data22 = {{#if:17 October 2024 (JD 2460600.5) |Epoch 17 October 2024 (JD 2460600.5)}} | data23 = {{#if:0 | Uncertainty parameter 0}} | label24 = Observation arc | data24 = 74.87 yr (27,345 d) | label25 = Earliest precovery date | data25 = | label26 = {{#switch:{{{apsis}}} |apsis|gee|barion|center|centre|(apsis)=Apo{{{apsis}}} |Ap{{#if:|{{{apsis}}}|helion}}}} | data26 = 2.5614 AU | label27 = Peri{{#if:|{{{apsis}}}|helion}} | data27 = 0.8364 AU | label28 = Peri{{#if:|{{{apsis}}}|apsis}} | data28 = | label29 = {{#switch:{{{apsis}}} |helion|astron=Ap{{{apsis}}} |Apo{{#if:|{{{apsis}}}|apsis}}}} | data29 = | label30 = Periastron | data30 = | label31 = Apoastron | data31 = | label32 = Template:Longitem | data32 = 1.6989 AU | label33 = Template:Longitem | data33 = | label34 = Eccentricity | data34 = 0.5077 | label35 = Template:Longitem | data35 = 2.214 yr (809 d) | label36 = Template:Longitem | data36 = | label37 = Template:Longitem | data37 = | label38 = Template:Longitem | data38 = 223.31° | label39 = Template:Longitem | data39 = Template:Deg2DMS / day | label40 = Inclination | data40 = 12.16° | label41 = Template:Longitem | data41 = | label42 = Template:Longitem | data42 = 356.59° | label43 = Template:Longitem | data43 = | label44 = Template:Longitem | data44 = | label45 = Template:Longitem | data45 = 224.76° | label46 = Template:Nowrap | data46 = | label47 = Satellite of | data47 = | label48 = Group | data48 = | label49 = {{#switch: |yes|true=Satellites |Known satellites}} | data49 = | label50 = Star | data50 = | label51 = Earth MOID | data51 = 0.03853 AU (14.9948 LD) | label52 = Mercury MOID | data52 = | label53 = Venus MOID | data53 = | label54 = Mars MOID | data54 = | label55 = Jupiter MOID | data55 = | label56 = Saturn MOID | data56 = | label57 = Uranus MOID | data57 = | label58 = Neptune MOID | data58 = | label59 = TJupiter | data59 =
| header60 = Proper orbital elements<ref name="Proper" />
| label61 = Template:Longitem
| data61 = {{#if: |{{{p_semimajor}}} AU}}
| label62 = Template:Longitem
| data62 =
| label63 = Template:Longitem
| data63 =
| label64 = Template:Longitem
| data64 = {{#if: |{{{p_mean_motion}}} degTemplate:\yr}}
| label65 = Template:Longitem
| data65 = {{#if:|{{#expr:360/1 round 5}} yr
({{#expr:365.25*360/1 round 3}} d) }}
| label66 = Template:Longitem
| data66 = {{#if:13.655|13.655 arcsecTemplate:\yr }}
| label67 = Template:Longitem
| data67 = {{#if:−35.824|−35.824 arcsecTemplate:\yr}}
| header70 = Template:Anchor{{#if:yes| Physical characteristics|Physical characteristics}}
| label71 = Dimensions | data71 = Template:Val<ref name="Busch-2007b" /> | label72 = Template:Longitem | data72 = Template:Ubl | label73 = Template:Longitem | data73 = | label74 = Template:Longitem | data74 = | label75 = Template:Longitem | data75 = | label76 = Flattening | data76 = | label77 = Circumference | data77 = | label78 = Template:Longitem | data78 = | label79 = Volume | data79 = | label80 = Mass | data80 = >Template:ValTemplate:Efn | label81 = Template:Longitem | data81 = >Template:Val<ref name="Busch-2007b" /> | label82 = Template:Longitem | data82 = | label83 = Template:Longitem | data83 = | label84 = Template:Longitem | data84 = | label85 = Template:Longitem | data85 = Template:Val<ref name="Busch-2007b" /> | label86 = Template:Longitem | data86 = | label87 = Template:Longitem | data87 = | label88 = Template:Longitem | data88 = | label89 = Template:Longitem | data89 = | label90 = Template:Longitem | data90 = | label91 = Template:Longitem | data91 = | label92 = Template:Longitem | data92 = | label93 = {{#if:yes |Template:Longitem |Albedo}} | data93 = Template:Ubl | label94 = Temperature | data94 =
| data100 = {{#if:|
{{#if:|}}{{#if:|}}{{#if:|}}{{#if:|}}| Surface temp. | min | mean | max |
|---|---|---|---|
| {{{temp_name1}}} | |||
| {{{temp_name2}}} | |||
| {{{temp_name3}}} | |||
| {{{temp_name4}}} |
}}
| label101 = Surface absorbed dose rate | data101 = | label102 = Surface equivalent dose rate | data102 = | label103 = Template:Longitem | data103 = Template:Ubl | label104 = Template:Longitem | data104 = | label105 = Template:Longitem | data105 = | label106 = Template:Longitem | data106 = Template:Ubl | label107 = Template:Longitem | data107 =
| header110 = Atmosphere
| label111 = Template:Longitem | data111 = | label112 = Template:Longitem | data112 = | label113 = Composition by volume | data113 =
| below = {{#if:||Template:Reflist }}
}}{{#invoke:Check for unknown parameters|check|unknown=Template:Main other|preview=Page using Template:Infobox planet with unknown parameter "_VALUE_"|ignoreblank=y| abs_magnitude | adjective | adjectives | albedo | allsatellites | alt_names | angular_dist | angular_size | aphelion | apoapsis | apsis | apoastron | arg_peri | asc_node | atmosphere | atmosphere_composition | atmosphere_ref | avg_speed | axial_tilt | background | barycentric | bgcolour | caption | circumference | declination | density | dimensions | discovered | discoverer | discovery_method | discovery_ref | discovery_site | earliest_precovery_date | eccentricity | epoch | equatorial_radius | escape_velocity | exosolar planets | extrasolarplanet | family | flattening | group | image | image_alt | image_scale | inclination | jupiter_moid | label_width | long_periastron | magnitude | mars_moid | mass | max_temp_1 | max_temp_2 | max_temp_3 | max_temp_4 | mean_anomaly | mean_diameter | mean_motion | mean_orbit_radius | mean_radius | mean_temp_1 | mean_temp_2 | mean_temp_3 | mean_temp_4 | mercury_moid | min_temp_1 | min_temp_2 | min_temp_3 | min_temp_4 | minorplanet | moid | moment_of_inertia_factor | mp_category | mp_name | mpc_name | name | named_after | neptune_moid | node_rate | note | observation_arc | orbit_diagram | orbit_ref | p_eccentricity | p_inclination | p_mean_motion | p_orbit_ref | p_semimajor | periapsis | periastron | perihelion | perihelion_rate | period | physical_ref | polar_radius | pole_ecliptic_lat | pole_ecliptic_lon | pronounce | pronounced | right_asc_north_pole | rot_velocity | rotation | satellite_of | satellites | saturn_moid | scale_height | semi-amplitude | semimajor | sidereal_day | single_temperature | spectral_type | star | surface_area | surface_grav | surface_pressure | surface_absorbed_dose_rate | surface_equivalent_dose_rate | symbol | synodic_period | temp_name1 | temp_name2 | temp_name3 | temp_name4 | time_periastron | tisserand | uncertainty | uranus_moid | venus_moid | volume }} Template:Mp (provisional designation Template:Mp) is a risk-listed asteroid, classified as a near-Earth object and potentially hazardous asteroid of the Apollo group, approximately Template:Convert in diameter.<ref name="Busch-2007b" /> It once had the highest known probability of impacting Earth.<ref name="impact-risk-summary"/> In 2002, it had the highest Palermo scale rating with a value of 0.17 and a probability of 1 in 306 (0.33%) for a possible collision in 2880.<ref name="NEO-1950DA"/><ref name="Giorgini-2002"/> Since that time, the estimated risk has been updated several times. In December 2015, the odds of an Earth impact were revised to 1 in 8,300 (0.012%) with a Palermo scale rating of −1.42.<ref name="impact-risk-summary"/> Template:As of, it is listed on the Sentry Risk Table with the highest cumulative Palermo scale rating of −0.92.<ref name="risk-table" /><ref name="ESASSP_2022">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Template:Mp is not assigned a Torino scale rating, because the 2880 date is over 100 years in the future. As of 29 April 2025, the odds of an Earth impact are 1 in 2,600 (0.039%).<ref name="risk-table" /><ref name="impact-risk-summary"/>
Discovery and nomenclatureEdit
Template:Mp was first discovered on 23 February 1950 by Carl A. Wirtanen at Lick Observatory.<ref name=jpldata/> It was observed for seventeen days<ref name="Giorgini-2002" /> and then lost because this short observation arc resulted in large uncertainties in Wirtanen's orbital solution. On 31 December 2000, it was recovered at Lowell Observatory and was announced as Template:Mp on 4 January 2001.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Just two hours later it was recognized as Template:Mp.<ref name="Giorgini-2002" /><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
ObservationsEdit
On 5 March 2001, Template:Mp made a close approach to Earth at a distance of Template:Convert.<ref name=jpl-close/> It was studied by radar at the Goldstone and Arecibo observatories from March 3 to 7, 2001.<ref name="Giorgini-2002" />
The studies showed that the asteroid has a mean diameter of 1.1 km, assuming that Template:Mp is a retrograde rotator.<ref name="Farnocchia-2014" /> Optical lightcurve analysis by Lenka Šarounová and Petr Pravec shows that its rotation period is Template:Val hours. Due to its short rotation period and high radar albedo, Template:Mp is thought to be fairly dense (more than 3.5 g/cm3, assuming that it has no internal strength) and likely composed of nickel–iron.<ref name="Busch-2007b" /> In August 2014, scientists from the University of Tennessee determined that Template:Mp is a rubble pile rotating faster than the breakup limit for its density, implying the asteroid is held together by van der Waals forces rather than gravity.<ref name="Rozitis-2014" /><ref name="tntoday" />
Template:Mp made distant approaches to Earth on 20 May 2012, 5 February 2021 and 5 February 2023.<ref name=jpl-close/> However, at these times it was a quarter to half an AU away from Earth, preventing more useful astrometrics and timing that occurs when an object is closer to Earth. The next close approach that presents a good opportunity to observe the asteroid will be on 2 March 2032, when it will be Template:Convert from Earth. The following table lists the approaches closer than 0.1 AU until the year 2500.<ref name="jpl-close-hor"/> By 2136 the close approach solutions are becoming notably more divergent.Template:Citation needed
| CitationClass=web
}} Soln.date: 2024-Dec-05 05:58:05</ref> |
Date | JPL SBDB nominal geocentric distance (AU) |
uncertainty region (1-sigma) |
|---|---|---|---|
| 2 March 2032 | Template:Convert | ±10 km | |
| 19 March 2074 | Template:Convert | ±30 km | |
| 10 March 2105 | Template:Convert | ±43 km | |
| 11 March 2136 | Template:Convert | ±387 km | |
| 8 March 2187 | Template:Convert | ±1717 km | |
| 20 March 2218 | Template:Convert | ±8712 km | |
| 18 March 2373 | Template:Convert | ±2508 km | |
| 6 March 2455 | Template:Convert | ±1650 km |
| Date | JPL Solution | Impact probability |
|---|---|---|
| 5 April 2002 | <ref name="Giorgini-2002"/> | 1/306 |
| 7 December 2015 | <ref>Template:Cite journal</ref> | 1/8300 |
| 29 March 2022 | citation | CitationClass=web
}}</ref> || 1/34000 |
| 18 June 2024 | <ref>Template:Cite journal</ref> | 1/2600 |
| 23 January 2025 | JPL276 | 1/2600 |
Possible Earth impactEdit
Template:Mp has one of the best-determined asteroid orbital solutions. This is due to a combination of:<ref name="Giorgini-2002" />
- an orbit moderately inclined (12 degrees)<ref name=jpldata/> to the ecliptic plane (reducing in-plane perturbations);
- high-precision radar astrometry, which provides its distance and is complementary to the measurements of angular positions;
- a 74-year observation arc;<ref name=jpldata/>
- an uncertainty region controlled by resonance.<ref name="Giorgini-2002" />
Main-belt asteroid 78 Diana (~125 km in diameter) will pass about Template:Convert from Template:Mp on 5 August 2150.<ref name="Giorgini-2002" /> At that distance and size, Diana will perturb Template:Mp enough so that the change in trajectory is notable by 2880 (730 years later). In addition, over the intervening time, Template:Mp's rotation will cause its orbit to slightly change as a result of the Yarkovsky effect. If Template:Mp continues on its present orbit, it may approach Earth on 16 March 2880, though the mean trajectory passes many millions of kilometres from Earth, so Template:Mp does not have a significant chance of impacting Earth. Template:As of, according to the latest solution dated 2 February 2025, the probability of an impact in 2880 is 1 in 2,600 (0.039%).<ref name=impact-risk-summary/>
The energy released by a collision with an object the size of Template:Mp would cause major effects on the climate and biosphere, which would be devastating to human civilization. The discovery of the potential impact heightened interest in asteroid deflection strategies.Template:Citation needed
See alsoEdit
- Template:Section link
- Asteroid impact prediction
- Earth-grazing fireball
- List of asteroid close approaches to Earth
NotesEdit
ReferencesEdit
External linksEdit
- MPEC 2001-A26 : 1950 DA = 2000 YK66 (K00Y66K). MPC 4 January 2001
- 3D model Rotating model of the asteroid (preferred rotation model is retrograde, NeoDys)
- Asteroid Lightcurve Database (LCDB), query form (info Template:Webarchive)
- Asteroids and comets rotation curves, CdRTemplate:Snd Observatoire de Genève, Raoul Behrend
- Discovery Circumstances: Numbered Minor Planets (25001)-(30000)Template:Snd Minor Planet Center
- Template:NeoDys
- Template:JPL small body
Template:Minor planets navigator Template:Planetary defense Template:Portal bar Template:Authority control