Contents  on 20 February '17

Asteroid/Comet Connection (A/CC) Resources:

The latest A/CC news is available via framed access, RSS news feed RSS news feed, or redirection.

Navigation tips: Use the << and >> arrows on the menus for each regular section (Observers, Risks, etc.) to move to the previous and next day's news for that section. Use the Index menu item to access specific days through a calendar interface. To keep track of what's new each day, watch the Chronology section.

Traffic Report  on 20 February '17

Five objects reported inside ten LD

There are five transient natural objects reported traveling within ten lunar distances (LD) of our home world today. Within Earth's SOI (sphere of gravitational influence), 2017 DB comes its closest to Earth on this passage, reaching 1.82 LD at 1633 UTC, and 2017 DF exits the SOI, going from 2.21 to 2.84 LD. Both are NHATS targets.

Much further away, radar/NHATS target 2017 CF32 exits our ten-LD traffic reporting zone, moving from 9.15 to 10.03 LD. Tomorrow risk-listed radar target 2017 BY93 comes inside ten LD.

Earth passage I D ~Size Distance Today  Notes
1.82 LD today2017 DB 13 m  1.82 LD NHATS target, inside Earth SOI, Earth closest at 1633 UTC
2.09 LD yesterday2017 DF 16 m  2.21 to 2.84 LD exits Earth SOI, NHATS target
2.57 LD Feb. 102017 CF32 21 m  9.15 to 10.03 LD exits ten LD, radar/NHATS target - DOU
3.58 LD Feb. 242017 CP1 40 m  5.01 from 5.78 LD radar/NHATS target - DOU
4.63 LD Feb. 172017 BW 69 m  5.66 to 6.35 LD radar/NHATS target

This report was generated at 1941 UTC. Today's DOU MPEC announces the discovery of two already departed risk-listed objects: 2017 CY32, which passed us at 1.63 LD on February 2nd, and 2017 BF136, which went by at 7.86 LD on the same day. The DOU also reports follow-up for 2017 CF32, inbound NHATS target 2017 CP1, 2017 BY93, and, from late January, distant NHATS target 208023 1999 AQ10.

Approaching (sorted by 10-LD bubble entry date)
2.37 LD Feb. 232017 BY93 82 m  < 10 LD tomorrow, radar target, risk - DOU
2.7   LD March 22012 DR32 41 m  < 10 LD Feb. 28, uncertainty +/- 4.1333 hours
8.34 LD March 161998 SL36 309 m  < 10 LD March 14, radar target
7.63 LD March 262015 TC25 4 m  < 10 LD March 17, radar/NHATS target, risk
4.57 LD April 192014 JO25 812 m  < 10 LD April 18, radar target
7.9   LD May 292017 CS 451 m  < 10 LD May 26, uncertainty +/- 42 mins.

Notes: Ten times the distance to the Moon (ten LD) has no astronomical importance but is a useful boundary for reporting on transient natural objects that approach the actually significant gravitational sphere of influence (SOI), which has a radius of about 2.41 LD from Earth's center. This puts a focus on some of the most important and very best NEO observation work, representative of the much larger NEO discovery and tracking effort. "Distant" is used here to describe an object that has come within ten LD since A/CC began these traffic reports (2007) but is not now so close. Object distances are derived by A/CC from JPL Horizons data. See also current sky chart and object details (alt-details), ephemerides, and today's timeline.

NEOCP Activity  on 20 February '17

The MPC's NEO Confirmation Page has 40 listings

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had 40 objects listed. Of these, 21 were "one nighters." So far The Tracking News has counted a total of 41 listings on the NEOCP today.

To learn how observers use the NEOCP, see the Practical guide on how to observe NEOCP object at Suno Observatory by Birtwhistle et al.

New MPECs  on 20 February '17

Minor Planet Electronic Circulars

As of last check at 2358 UTC, there has been one MPEC posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.

<< DOU on 20 Feb. '17 >>  MPEC 2017-D23 - "13:04 UT" - Daily Orbit Update

Observers  on 20 February '17

A total of 27 observers appear in today's MPEC.

CodeObserver / observatory
705"Kristie Nault via Apache Point Obs. in New Mexico, 1 in MPEC 2017-D23 -- 2017 CA33
H21Astronomical Research Obs. Westfield in Illinois, 7 in MPEC 2017-D23 -- 2017 BS6, 2017 BP91, 2016 YR8, 2016 WU3, 2016 AU8, 2014 YN44, 311321
T05ATLAS Haleakala in Hawaii, 14 in MPEC 2017-D23 -- 2016 CA138, 2008 CA6, 2002 LS32, 90075, 413002, 248083, 153951, 144861, 138846, 138155, 10636, 4954, 3199, 1036
T08ATLAS Mauna Loa in Hawaii, 5 in MPEC 2017-D23 -- 2017 CP1, 2011 WO41, 40267, 11398, 5693
160Castelmartini Obs. in Italy, 3 in MPEC 2017-D23 -- 2013 YE38, 137170, 7888
807|Robert Holmes in Illinois via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 7 in MPEC 2017-D23 -- 2017 CO5, 2017 CN32, 2017 CM1, 2017 BX6, 2017 BF29, 2017 BC30, 2017 AO13
I17Cupillari Obs. in Pennsylvania, 1 in MPEC 2017-D23 -- 136635
Q62`Steven M. Tilley in Louisiana via iTelescope Obs. Siding Spring in New South Wales, 1 in MPEC 2017-D23 -- 2017 BL30
K93LCOGT Sutherland C in South Africa, 1 in MPEC 2017-D23 -- 2017 BC136
Z21LCOGT Tenerife Aqawan A#1 in the Canary Islands, 1 in MPEC 2017-D23 -- 2017 CF32
H01Magdalena Ridge Obs. (MRO) in New Mexico, 3 in MPEC 2017-D23 -- 2017 CY32, 2017 BG136, 2017 BD136
Z22MASTER IAC Obs. in the Canary Islands, 1 in MPEC 2017-D23 -- 2011 WO41
K95MASTER-II Sutherland in South Africa, 2 in MPEC 2017-D23 -- 481918, 310842
C94MASTER-II Tunka in Russia, 2 in MPEC 2017-D23 -- 40267, 11398
568_Marco Micheli on Mauna Kea in Hawaii, 1 in MPEC 2017-D23 -- 2017 BE136
474Mt. John Obs. in New Zealand, 9 in MPEC 2017-D23 -- 2017 CO5, 2017 CO1, 2017 BL6, 2017 BG32, 2017 BF29, 2017 BC30, 2016 YX7, 2008 EE68, 2003 FR6
G96Mt. Lemmon Survey (MLS) in Arizona, 3 in MPEC 2017-D23 -- 2017 CY32, 2017 BG136, 2017 BF136
Z80Northolt Branch Obs. in England, 1 in MPEC 2017-D23 -- 2017 CF32
F51Pan-STARRS 1 (PS1) in Hawaii, 7 in MPEC 2017-D23 -- 2017 CF32, 2017 CA33, 2017 BG136, 2017 BE136, 2017 BD136, 2017 BC136, 2005 YV55
H45Petit Jean Mtn. South Obs. (PJMSO) in Arkansas, 12 in MPEC 2017-D23 -- 2017 BL30, 2017 BK92, 2002 LS32, 2001 QE34, 96590, 54789, 443103, 349507, 347813, 152931, 138846, 12538
W25RMS Obs., 1 in MPEC 2017-D23 -- 2017 CF32
G40!M. Kumrucu-Lohmiller in Massachusetts via Canary Islands Obs. in the Canary Islands, 1 in MPEC 2017-D23 -- 2017 BY93
Y00SONEAR in Brazil, 2 in MPEC 2017-D23 -- 480934, 1864
W34Squirrel Valley Obs. in North Carolina, 1 in MPEC 2017-D23 -- 5828
I52Steward Obs. Mt. Lemmon Station in Arizona, 1 in MPEC 2017-D23 -- 2017 BF136
T12UH/Tholen NEO Follow-Up 2.24m Telescope in Hawaii, 1 in MPEC 2017-D23 -- 208023
I15Wishing Star Obs. in Rhode Island, 2 in MPEC 2017-D23 -- 2001 QE34, 443103
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 20 February '17

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS and JPL at 2358 UTC)
See the CRT page for a list of all objects rated recently as risks and our ephemerides page for a list of risk-listed objects under current observation.
The time horizon for JPL is 100 years from today and for NEODyS is usually the year 2090. Both also post impact solutions beyond 100 years for a few special objects.
For the latest official risk assessments, and for explanations of the terminology, see the JPL NEO Program Sentry and NEODyS CLOMON2 risk pages.





Notes for Today's Latest Risk Assessments
2017 CA33JPL Sentry16392034-2116165.6e-09-7.74-8.440JPL: "Analysis based on 6 observations spanning 1.7670 days (2017-Feb-04.51994 to 2017-Feb-06.28698)." Diameter approximately 0.046 km. from mean, weighted H=24.4.
2017 CY32JPL Sentry16392047-210754.0e-09-9.86-10.00JPL: "Analysis based on 18 observations spanning .12763 days (2017-Feb-01.39999 to 2017-Feb-01.52762)." Diameter approximately 0.007 km. from mean, weighted H=28.5.
2017 BF136JPL Sentry16392050-208181.2e-08-8.12-8.550JPL: "Analysis based on 13 observations spanning 1.0354 days (2017-Jan-31.33373 to 2017-Feb-01.36918)." Diameter approximately 0.021 km. from mean, weighted H=26.1.
2017 BY93NEODyS1639206811.03e-08-6.87-6.870NEODyS: "Based on 96 optical observations (of which 1 are rejected as outliers) from 2017-01-26.500 to 2017-02-18.976."
2017 BL30NEODyS19002029-2116131.55e-04-2.55-2.550NEODyS: "Based on 196 optical observations (of which 0 are rejected as outliers) from 2017-01-28.379 to 2017-02-20.182."
JPL Sentry16392029-205251.9e-05-3.47-3.470JPL: "Analysis based on 196 observations spanning 22.803 days (2017-Jan-28.37792 to 2017-Feb-20.18096)." Diameter approximately 0.072 km. from mean, weighted H=23.4.

Legend: VI# = VI count, Prob Cum = cumulative probability, PS Cum/Max = cumulative/maximum Palermo Scale, TS = Torino Scale (next 100 years)

An impact solution, also known as a "virtual impactor" (VI), is not a prediction but rather a possibility derived from a variant orbit calculation that cannot be eliminated yet based on the existing data. Elimination can come quickly with just a little further observation or may take weeks or months, sometimes years. Once superceded or eliminated, a former impact solution has zero relevance to an object's risk. See Jon Giorgini's "Understanding Risk Pages" to learn more.

Chronology  on 20 February '17

Times are UTC for when items were noted or added by The Tracking News.

1941Generated Traffic Report
1900Noted that NEODyS has updated its 2017 BL30 risk assessment - see above
1639Noted that JPL Sentry has posted 2017 BF136 as an impact risk - see above
Noted that JPL Sentry has updated its 2017 BL30 risk assessment - see above
Noted that NEODyS has updated its 2017 BY93 risk assessment - see above
Noted that JPL Sentry has posted 2017 CA33 as an impact risk - see above
Noted that JPL Sentry has posted 2017 CY32 as an impact risk - see above
Grabbed MPEC 2017-D23 - Daily Orbit Update - see above