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Jan 30, 2017

The Near-Earth Object 2016 WF9 , the Flyby, the Hullabaloo, and the Facts

The Discovery

An artist’s rendition of 2016 WF9 as it passes Jupiter’s orbit inbound
toward the Sun. Image: Courtesy NASA/JPL-Caltech
On 2016 November 27 at 6:27:07.77(UTC) the NEOWISE project took the first of a series of images of a "new object." A report for this new object was submitted to the Minor Planet Center(MPC) The "object"(with its observations) was posted to the NEO Confirmation Page. Observers from four other observatories submitted follow-up observations, and on 2016 November 30, 04:19 (UTC) the MPC issued a Minor Planet Electronic Circular (MPEC 2016-W125: 2016 WF9) announcing the discovery. This object was given the provisional designation 2016 WF9. This designation tells the world that this asteroid was discovered in the year 2016 during the half-month of November 16-30(W) and it was the 231st(F9) discovery of that half-month.

Follow-up After Discovery 

After the MPC had issued The Minor Planet Electronic Circular announcing the discovery, follow-up observations were made, and prediscovery observations were found adding up to a total of 61 observations spanning 111 days. Each observations records were in the sky 2016 WF9 was seen from the given location at the given time. Given that asteroid and comets follow the laws of planetary motion and move through the solar system in elliptical orbits each observation eliminates many  possibilities of where in the solar system the asteroid can be in the future. Near-Earth Object observational data is generally made available within 24 hours after it is submitted to the MPC.  Anyone who has the knowledge and the software can do their own orbit determination. The available observational data for 2016 WF9 rules out any impact for the foreseeable future.  It should also be noted that observations from other observatories serve as a cross check.

What set 2016 WF9 apart from other Near-Earth Objects is first it has a Tisserand Parameter of 2.893. Most asteroids have a Tisserand Parameter greater than 3, and most Jupiter Family Comets have a Tisserand Parameter between 2 and 3. In other words, it has a "comet-like" orbit.  The second thing about 2016 WF9 is it is rather dark. Given that  2016 WF9 has a "comet-like" orbit and is rather dark lends astronomers to believe it may have cometary origins; however, no cometary activity has been observed yet. 

2016 WF9 Comes to the  Attention of the General Public

On December 29, 2016, NASA call 2016 WF9 to the attention of the public at large by issuing the press release titled "NASA's NEOWISE Mission Spies One Comet, Maybe Two." The press release reported information about the comet C/2016 U1 NEOWISE and 2016 WF9 including information on an unremarkable close-approach and stated: "The trajectory of 2016 WF9 is well understood, and the object is not a threat to Earth for the foreseeable future." In the days that follow this story was picked up by other news outlets, some which blurred the line between journalism and creative writing.

Keep in mind as a story moves through the blogosphere it changes like the "telephone game." The original story is misread, poorly translated, misunderstood, etc. then rewritten by other writers with the wrong information. Then other writers then use the revised story as a source for new stories adding to the madness. One should seek out the original story(and see if it is reliable).
Background
(as of 2017-01-29 ) 
  • Object: 2016 WF9
  • Orbit Type:  Apollo [NEO] Potentially Hazardous Asteroid (NOTE: this is over hundreds if not  thousands of years) 
  • Approximate Diameter:   270 m - 590 m( 885.827 feet to  1935.696 feet)(Absolute Magnitude: H= 20.2)
  • On the Sentry Risk Table: No (Removed ) 2016-12-20 16:00
  • On the NEODyS CLOMON2 risk page: No (Removed )
  • First(Precovery) Observation was made: 2016 10 10.42213
  • First(Precovery) Observed by: Pan-STARRS 1, Haleakala (MPC Code F51) The Precovery  M.P.E.C.: MPEC 2017-A66 : DAILY ORBIT UPDATE (2017 JAN. 9 UT)
  • Discovery (First) observation was made: 2016 11 27.26884
  • Discovery (First )observation by: NEOWISE (MPC Code C51)The Discovery M.P.E.C.: MPEC 2016-W125: 2016 WF9
  • Last Observation (publish): 2017 01 29.18221  (by  LPL/Spacewatch II (MPC Code 291 )  )
  • Data-Arc Span (publish): 111 days
  • Number of Optical Observations(published): 61
  • Observatories Reporting (Published) Observations(MPC Code):
    • (291) LPL/Spacewatch II, US/Arizona. 
    • (474) Mount John Observatory, Lake Tekapo, New Zealand.
    • (807) Cerro Tololo Observatory, La Serena, Chile. 
    • (C51) NEOWISE
    • (F51) Pan-STARRS 1, Haleakala, US/Hawaii.
    • (Q64) Siding Spring-LCOGT B, Australia/NSW.
    • (T12) Mauna Kea-UH/Tholen NEO Follow-Up (2.24-m), US/Hawaii.
  • Perihelion Distance: 0.9817420310009939(AU)
  • Aphelion Distance:  4.759885397693941
  • Earth MOID: 0.0145594 AU ( 5.666 (LD)) or 1,353,380.78  miles (2,178,055.239 (KM))
  • Next Close-Approach to Earth:  Will safely pass Earth on 2017-Feb-25 at a Nominal Distance of  0.340740651006311 (AU) (132.607 (LD)) or  31,673,822.283 miles (50,974,075.848 (KM)) - to put things in perspective "If" the Earth Was the Size of a Basketball this would be  ~ 3,126.54 feet (952.97meters) away) 
Correction


This past has been corrected to show that 2016 WF9 was at one listed on the JPL Sentry and NEODyS risk list. see The Tracking News 30 November 2016 #2016 WF9 The author thanks the reader for the correction,
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