Jan 17, 2017

The Asteroid 2012 TC4 is Making a Safe Close-Approach on October-12-2017 Please Stand By For a Media Storm

The First in a Series
This artist's concept shows a broken-up asteroid.
ImageCourtesy NASA/JPL-Caltech 
On October 12, 2017, the asteroid 2012 TC4 is projected to make an exceptionally close approach to Earth, and it is possible that the media (alternative, mainstream,  print, broadcast, and social) will go wild. Writeups will range from well written to poorly written, originally written to carbon copies, well research to poorly research, well intentioned to bad intentioned, and so forth. How is the consumer of media to make heads or tails of the hodgepodge of choices out there? The author plans a series of posts to give some background on 2012 TC4 in particular, some general knowledge about asteroids, their orbit, asteroid observing, asteroid risk list, and source information, to help the read navigate the mishmash of media out there.

What makes the Close-Approach on October 12, 2017, exceptional?

If we count 2008 TC3 and 2014 AA(both were small and impacted the Earth and would tie for first) 2012 TC4 could come in as the sixth closest known approach to date.  While there is some uncertainty about how close the close-approach will be, there is sufficient observational data to rule out an impact on October 12, 2017, When talking about astronomical distances it can be tough to wrap one's head around this can lead one to use of analogies such as close shave which is not aways helpful. If one uses a basketball to serve as a model for the Earth it may be easier to grasp.

The Model  (the Basketball Size Earth) 

  • Earth (Equatorial) radius: 4.2634965e-5 AU 3963.17 miles (6378.1 KM) - for the model 4.69507082121091 inches (11.93 CM)
  • Earth (Equatorial) Circumference(assuming around Earth): 0.000267883358316 AU 24,901.32 miles (40,074.78 KM) -for the model 29.5 inches (74.93 CM)
  • ISS(Perigee): 2.67383e-6 AU 248.55 miles (400.00 KM) -for the model 0.29 inches ( 0.75CM)
  • ISS(apogee): 2.7407e-6 AU 254.76 miles (400.00 KM) -for the model 0.3 inches ( 0.77CM)
  • Geosynchronous orbit: 0.00023921463 AU (0.093 Lunar Distance (LD)) or 22236.39 miles (35786.00 KM)  -for the model (after subtracting the radius)- 2.2 feet ( 0.67 M)
  • Lunar Distance (LD): 0.003 AU or 238606.54  22236.39 miles (35786.00 KM)  -for the model (after subtracting the radius)-  23.16 feet (7.06 M)
  • Astronomical Unit: 389.171 Lunar Distance (LD) or 9.296e+7 miles (1.496e+8 KM)   -for the model   1.7 miles  (2.7 KM)

(as of 2017-01-16 ) 

  • Object: 2012 TC4
  • Orbit Type: Apollo [NEO]
  • Approximate Diameter: 15 m - 33 m (  49.2126 feet to 108.268  feet)(Absolute Magnitude: H= 26.7)
  • On the Sentry Risk Table:  Yes 
    •  NOTE this is NOT a prediction of an impact but rather a statement there is insufficient observational data rule out an impact -- for information read  Understanding Risk Pages by Jon Giorgini
  • Torino Scale(NEODyS CLOMON2)0
    • "The likelihood of a collision is zero, or is so low as to be effectively zero. Also applies to small objects such as meteors and bodies that burn up in the atmosphere as well as infrequent meteorite falls that rarely cause damage.."
  • On the NEODyS CLOMON2 risk page: Yes
    • NEODyS Recovery Campaign: 2017-08-31t o 2017-10-24
  • Discovery observation was made: 2012 10 04.467661
  • Discovery observation was made by Pan-STARRS 1 (MPC Code F51) The Discovery M.P.E.C.: MPEC 2012-T18 : 2012 TC4
  • Last Observation (publish): 2012 10 11.74842   (by Volkssternwarte Drebach, Schoenbrunn(MPC code 113))
  • Data-Arc Span (publish): 7 days
  • Number of Optical Observations(published):301
  • Observatories Reporting (Published) Observations(MPC Code):
    • (089) Nikolaev,  Ukraine.
    • (104) San Marcello Pistoiese, Italy.
    • (113) Volkssternwarte Drebach, Schoenbrunn, Germany.
    • (204) Schiaparelli Observatory, Italy
    • (291) LPL/Spacewatch II, US/Arizona.
    • (300) Bisei Spaceguard Center-BATTeRS, Japan.
    • (461) University of Szeged, Piszkesteto Stn (Konkoly), Hungary.
    • (470) Ceccano, Italy.
    • (568) Mauna Kea, US/Hawaii.
    • (695) Kitt Peak, US/Arizona.
    • (703) Catalina Sky Survey, US/Arizona.
    • (716) Palmer Divide Observatory, Colorado Springs, US/Colorado.
    • (718) Tooele, US/Utah.  
    • (857) Iowa Robotic Observatory, Sonoita, US/Arizona.
    • (900) Moriyama, Japan.
    • (932) John J. McCarthy Obs., New Milford,  US/Connecticut.
    • (B04) OAVdA, Saint-Barthelemy, Italy. 
    • (B88) Bigmuskie Observatory, Mombercelli, Italy.
    • (C32) Ka-Dar Observatory, TAU Station, Nizhny Arkhyz, Russia.
    • (C77) Bernezzo Observatory, Italy.
    • (E10) Siding Spring-Faulkes Telescope South, Australia/NSW.
    • (F51) Pan-STARRS 1, Haleakala, US/Hawaii
    • (F65) Haleakala-Faulkes Telescope North, US/Hawaii.
    • (G40) Canary Islands Observatory, Canary Islands (Spain).
    • (G48) Doc Greiner Research Obs., Rancho Hildalgo,  US/New Mexico.
    • (H06) iTelescope Observatory, Mayhill, US/New Mexico.  
    • (H17) Angel Peaks Observatory, US/Colorado.
    • (H21) Astronomical Research Observatory, Westfield, US/Illinois.
    • (H36) Sandlot Observatory, Scranton, US/Kansas
    • (J16) An Carraig Observatory, Loughinisland, UK.
    • (J84) South Observatory, Clanfield, UK.
    • (J95) Great Shefford, UK.
  • Perihelion Distance: 0.9337184081730526(AU)
  • Aphelion Distance: 1.877515914032821
  • Goldstone Asteroid Schedule: Yes  2017 Oct ( Needs Astrometry: Yes Physical Ob
  • Near-Earth Object Human Space Flight Accessible Targets Study (NHATS): Yes
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