2000 SG344
{{short description|Small risk–listed near-Earth asteroid}}
{{DISPLAYTITLE:{{mp|2000 SG|344}}}}
{{Use dmy dates|date=September 2020}}
{{Infobox planet
|minorplanet = yes
|name = {{mp|2000 SG|344}}
|symbol =
|background = #FFC2E0
|image = Asteroid_2000_SG344.gif
|caption = {{mp|2000 SG|344}} seen on 29 September 2000, as a dim streak in the center of the image, moving against the background field of stars
|discoverer = D. J. Tholen
R. J. Whiteley
|discovery_site = Mauna Kea Obs.—UH88
|discovered = 29 September 2000
{{small|(first observation only)}}
|mpc_name =
|alt_names =
|epoch = 2020-May-31 (JD 2457400.5)
|observation_arc = 507 days (1.39 yr)
|uncertainty = 3
|aphelion = {{Convert|1.0429|AU|Gm|abbr=on|lk=on}}
|perihelion = {{Convert|0.91199|AU|Gm|abbr=on}}
|semimajor = {{Convert|0.97744|AU|Gm|abbr=on}}
|eccentricity = 0.06696
|inclination = 0.112202°
|asc_node = 191.91°
|mean_motion = 1.0198°/day
|mean_anomaly = 35.680°
|arg_peri = 275.35°
|moid = {{Convert|0.0008|AU|km|abbr=on}}
|mean_diameter = {{val|37|ul=m|}} (assumed)
15–70 meters
|satellites =
|mass = 7.1{{e|7}} kg (assumed)
|albedo =
|spectral_type =
}}
{{mp|2000 SG|344}} is a small Aten asteroid first observed in 2000. It is assumed to have a diameter of approximately {{convert|37|m|ft|abbr=off|sigfig=2|sp=us}} – or roughly twice that of the Chelyabinsk meteor – and an assumed mass of 1 E10 kg (71,000 tonnes), but the size is only known within about a factor 2. {{As of|2025|02}}, it is the largest object known to have a better than 1/1000 chance (0.1%) of impacting Earth and has the fifth highest cumulative Palermo scale rating at −2.77. The next good chance to observe the object will be in May 2028 when it passes {{convert|0.02|AU|km mi|abbr=on}} from Earth.
Because of its very Earth-like orbit and because it would have been near the Earth in 1971 (coinciding with the Apollo program), there was speculation that {{mp|2000 SG|344}} might not be an asteroid but a man-made object such as an S-IVB booster stage from a Saturn V rocket which would make it about 15 meters in diameter and much less massive. (cf. J002E3, the S-IVB booster of Apollo 12 which was mistaken for an asteroid.)
| class="wikitable" style="text-align:center; font-size: 0.9em;"
|+Upcoming Earth approaches ! Date & time ! Nominal distance ! uncertainty | ||
| 2028-May-07 03:32 ± 4 minutes | {{val|2931689|u=km}} | {{Nowrap|± {{val|46000}} km}} |
| 2030-Sep-22 22:36 ± 10 hours | {{val|5121080|u=km}} | {{Nowrap|± {{val|380000}} km}} |
Possible impacts with Earth
Until December 2004, it was considered to have the highest (though still very low) likelihood of any near-Earth object to impact Earth in the next 100 years. It is ranked a zero on the Torino scale of impact risk because of its small size (the scale is 0–10) and is listed on Sentry Risk Table. It was briefly surpassed in December 2004 by 99942 Apophis (which at the time was known only by its provisional designation {{mp|2004 MN|4}}). Smaller asteroids such as {{mpl|2006 JY|26}} and {{mpl|2006 RH|120}} have a greater chance of impacting Earth.
Based on 31 observations of {{mp|2000 SG|344}} made from May 1999 to October 2000, there is about a 1 in 360 chance that it will collide with Earth between 2069 and 2121. The greatest chance of impact is on 16 September 2071 with a 1 in 1000 chance of impact. Assuming the object is a rocky asteroid and that it reaches Earth's surface without exploding in the atmosphere, the impact energy released would be an estimated 1.0 megatons of TNT, comparable to the Tunguska and Chelyabinsk events, which could create an impact crater approximately {{convert|100|ft|m}} wide.
| class="wikitable sortable" style="font-size: 0.9em;"
! Date ! Impact ! JPL Horizons ! NEODyS ! uncertainty | ||||
| 2069-09-18 | 5 million | {{Convert|0.07|AU|e6km|abbr=unit|lk=on}} | {{Convert|0.08|AU|e6km|abbr=unit}} | {{Nowrap|± 32 million km}} |
| 2070-09-17 | 4300 | {{Convert|0.18|AU|e6km|abbr=unit}} | {{Convert|0.14|AU|e6km|abbr=unit}} | {{Nowrap|± 275 million km}} |
| 2071-09-10 | 7100 | {{Convert|0.43|AU|e6km|abbr=unit}} | {{Convert|0.35|AU|e6km|abbr=unit}} | {{Nowrap|± 462 million km}} |
| 2071-09-16 | 1000 | {{Convert|0.44|AU|e6km|abbr=unit}} | {{Convert|0.36|AU|e6km|abbr=unit}} | {{Nowrap|± 475 million km}} |
Proposed NASA mission
In 2008, NASA considered this asteroid as a possible target for a crewed mission (Artemis 2) using the Orion spacecraft, prior to a projected 2030 push to Mars.Into the Beyond: A Crewed Mission to a Near-Earth Object – [http://ti.arc.nasa.gov/m/project/neo/pdf/neo_crewed_mission.pdf text] [http://ti.arc.nasa.gov/m/project/neo/pdf/IAC-07-slides.pdf slides] Those plans were since abandoned. {{mp|2000 SG|344}} will be observable in May 2028 at an apparent magnitude of 19.
References
{{reflist|refs=
|title = JPL Small-Body Database Browser on 2000 SG344
|publisher = NASA
|url = https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=2000SG344&view=OPC
|accessdate = 18 May 2008 }}
|title = IAU Circular: MPEC 2000-U19
|date = 24 October 2000
|url = http://cfa-www.harvard.edu/mpec/K00/K00U19.html
|accessdate= 18 May 2008 }}
|title=Near-Earth Object Human Space Flight Accessible Targets Study (NHATS)
|publisher=NASA/JPL Near-Earth Object Program Office
|url=http://neo.jpl.nasa.gov/cgi-bin/nhats
|archive-url=https://web.archive.org/web/20130218125702/http://neo.jpl.nasa.gov/cgi-bin/nhats
|url-status=dead
|archive-date=18 February 2013
|accessdate=8 June 2012}}
|title={{mp|2000 SG|344}} Earth Impact Risk Summary
|date=7 April 2017
|url=https://cneos.jpl.nasa.gov/sentry/details.html#?des=2000%20SG344
|accessdate=12 November 2004
|archiveurl=https://web.archive.org/web/20041024225737/http://neo.jpl.nasa.gov/risk/2000sg344.html
|archivedate=24 October 2004 |url-status=live }}
|title=NASA Near Earth Object Program: Current Impact Risks
|url=http://neo.jpl.nasa.gov/risk/
|accessdate=12 November 2004
|url-status=dead |archiveurl=https://web.archive.org/web/20130529175100/http://neo.jpl.nasa.gov/risk/ |archivedate=29 May 2013 }}
|title = 2000 SG344: The Story of a Potential Earth Impactor
|last = Chodas |first = P. W. |author2= Chesley, S. R.
|date = November 2001
|journal = Bulletin of the American Astronomical Society
|volume = 33 | pages = 1196 |hdl = 2014/12396 |bibcode = 2001DDA....32.0803C }}
|title=Much Ado about 2000 SG344
|date=7 November 2000
|publisher=NASA
|url=https://science.nasa.gov/science-news/science-at-nasa/2000/ast06nov_2
|accessdate=19 May 2008
|url-status=live
|archiveurl=https://web.archive.org/web/20090117170401/https://science.nasa.gov/headlines/y2000/ast06nov_2.htm |archivedate=17 January 2009 }}
|title=Horizons Batch for 2069-09-18 11:46 Virtual Impactor Time
|publisher=JPL Horizons
|url=https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272000+SG344%27&START_TIME=%272069-09-18%2011:46%27&STOP_TIME=%272069-09-19%27&STEP_SIZE=%272%20days%27&QUANTITIES=%2720,39%27
|archive-url=https://web.archive.org/web/20220920021145/https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272000+SG344%27&START_TIME=%272069-09-18%2011:46%27&STOP_TIME=%272069-09-19%27&STEP_SIZE=%272%20days%27&QUANTITIES=%2720,39%27
|archive-date=2022-09-20
|url-status=live
|accessdate=2022-09-19}} RNG_3sigma = uncertainty range in km. (JPL#17/Soln.date: 2021-Apr-14 generates RNG_3sigma = {{val|32213496}} for 2069-09-18 11:46.)
|title=2000SG344 Ephemerides for 18 September 2069
|publisher=NEODyS (Near Earth Objects{{Snd}} Dynamic Site)
|url=https://newton.spacedys.com/neodys/index.php?pc=1.1.3.1&n=2000SG344&oc=500&y0=2069&m0=09&d0=18&h0=0&mi0=0&y1=2069&m1=09&d1=19&h1=0&mi1=0&ti=1.0&tiu=days
|archive-url=https://web.archive.org/web/20201209154241/https://newton.spacedys.com/neodys/index.php?pc=1.1.3.1&n=2000SG344&oc=500&y0=2069&m0=09&d0=18&h0=0&mi0=0&y1=2069&m1=09&d1=19&h1=0&mi1=0&ti=1.0&tiu=days
|archive-date=2020-12-09 |url-status=live
|accessdate=2020-12-09}}
|title=JPL Horizons: 2000 SG344 geocentric distance and uncertainty on 2028-May-07
|publisher=JPL Horizons
|url=https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272000+SG344%27&START_TIME=%272028-05-07%2003:32%27&STOP_TIME=%272028-05-08%27&STEP_SIZE=%272%20day%27&QUANTITIES=%2720,39%27
|accessdate=2023-06-10}}
|title=JPL Horizons: 2000 SG344 geocentric distance and uncertainty on 2030-Sep-22
|publisher=JPL Horizons
|url=https://ssd.jpl.nasa.gov/horizons_batch.cgi?batch=1&COMMAND=%272000+SG344%27&START_TIME=%272030-09-22%2022:36%27&STOP_TIME=%272030-09-23%27&STEP_SIZE=%272%20day%27&QUANTITIES=%2720,39%27
|accessdate=2023-06-10}}
{{Cite news|title=Closer encounter: Nasa plans landing on 40m-wide asteroid travelling at 28,000mph |last=Sample |first=Ian |date=7 May 2008 |work=The Guardian |url=https://www.theguardian.com/science/2008/may/07/starsgalaxiesandplanets.spaceexploration |access-date=9 May 2008 |archiveurl=https://web.archive.org/web/20080509181202/http://www.guardian.co.uk/science/2008/may/07/starsgalaxiesandplanets.spaceexploration |archivedate=9 May 2008 |url-status=live }}
}}
Further reading
- {{Cite journal | title = IAU Circular: MPEC 2000-U19 | date = 24 October 2000 | url = http://cfa-www.harvard.edu/mpec/K00/K00U19.html| accessdate= 18 May 2008 }}
- {{Cite journal | title = IAU Circular: MPEC 2000-U24 | date = 25 October 2000 | url = http://www.cfa.harvard.edu/mpec/K00/K00U24.html| accessdate= 9 May 2008 }}
- {{Cite journal | title = IAU Circular: MPEC 2000-V26 | date = 8 November 2000 | url = http://www.cfa.harvard.edu/mpec/K00/K00V26.html| accessdate= 9 May 2008 }}
External links
- NASA NEO Study [http://ti.arc.nasa.gov/project/neo/ home page]
- [http://ti.arc.nasa.gov/m/project/neo/pdf/NEO_feasibility.pdf Piloted Orion Flight Feasibility Study]
- {{NeoDys|2000+SG344}}
- {{ESA-SSA|2000SG344}}
- {{JPL small body}}
{{Small Solar System bodies}}
{{Authority control}}
{{DEFAULTSORT:2000 SG344}}
Category:Minor planet object articles (unnumbered)
Category:Potential impact events caused by near-Earth objects