17-23 July '06 - A/CC Small Object Report

ACC's Small Object Report for 17-23 July 2006

A semi-automated report compiled on 23 July 2006 at 2359 UTC

Four* small asteroids were reported in the last 168 hours, during which three were newly discovered.

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Editor's note: As asteroids go, "small" is defined as having an absolute magnitude (brightness) calculated at greater than H=22.0, which converts very roughly to a diameter under 135 meters. No matter how close they come to the Earth, the astronomical community does not classify such objects as "potentially hazardous." However, as demonstrated by the mile wide (1.6 km.) Barringer Crater in Arizona, blasted out by a "small" asteroid some 50,000 years ago, there are asteroids too small to be labeled "potentially hazardous" that actually could cause severe local damage. These are sometimes called "Tunguska-class objects" (TCOs), after the 1908 event probably caused by a comet fragment or asteroid too small to be classified today as hazardous but packing enough wallop to flatten a Siberian forest area the size of a large city.
NEODyS in December 2005 changed its main Risk page to classify "Objects too small to result in heavy damage on the ground" as having "absolute magnitude > 25," which corresponds to perhaps 35 meters wide. And JPL two months earlier started flagging (with a blue background) risk-listed objects of "Estimated diameter 50 meters or less" as "not likely to cause significant damage in the event of an impact, although impact damage does depend heavily upon the specific (and usually unknown) physical properties of the object in question."
Small asteroids that come close enough to Earth to be seen have significant potential for scientific study today, and for exploration and exploitation in the future. They present a sampling of distant asteroid populations and a few may be remnants of the event that created the Earth-Moon system.
Some of these objects are discovered while close to Earth moving across the sky quite quickly, when they are called "FMOs" or "VFMOs" (very fast moving objects). The discovery and follow-up tracking of asteroids with H>22.0 represents some of the most difficult and very best observing work being done today by amateur and professional astronomers around the world, and the page you are reading is dedicated to recognizing their ongoing successes.

Object Listings -- smallest objects first [ Alpha Index | 48 Hours | top ]

Size estimate: 13 meters per JPL H=27.12, MPC H=27.1 This object was listed from 22 July 2006 until today (23 July) as an impact risk. JPL classifies 2006 OK3 as an Apollo and calculates an Earth MOID of 0.000834 AU (0.32 LD), and reports this object passes Earth at 0.7 lunar distances (LD) on 23 July 2006 at 1044 UT. Observations are reported from the following observatories in MPECs 2006-O22 and 2006-O26: Siding Spring Survey (SSS) [E12] 2006-07-22 1414-1545, 26 pos. in MPEC 2006-O22, discovery (*) 2006-07-22 1939-1940, 3 pos. in MPEC 2006-O22, confirmation CEAMIG-REA [I77] 2006-07-23 0048-0054, 6 pos. in MPEC 2006-O26, follow-up Great Shefford Obs. [J95] 2006-07-23 0149-0155, 3 pos. in MPEC 2006-O26, follow-up 2006 OY4 (K06O04Y) [ JPL Orbit Viewer | NEODyS object home | news | viewing | index | top ]

Size estimate: 67 meters per JPL H=23.53, MPC H=23.5 JPL classifies 2006 OY4 as an Amor and calculates an Earth MOID of 0.087408 AU (34.01 LD), and reports this object will pass Earth at 35.3 LD on 30 July 2006. Observations are reported from the following observatories in MPEC 2006-O28: Siding Spring Survey (SSS) [E12] 2006-07-20 1428-1525, 5 pos. in MPEC 2006-O28, discovery (*) 2006-07-20 1648-1756, 5 pos. in MPEC 2006-O28, confirmation 2006-07-22 1414-1436, 17 pos. in MPEC 2006-O28, confirmation CEAMIG-REA [I77] 2006-07-22 0349-0356, 3 pos. in MPEC 2006-O28, confirmation 2006 MB (K06M00B) [ JPL Orbit Viewer | NEODyS object home | news | viewing | index | top ]

Size estimate: 105 meters per JPL H=22.55, MPC H=22.5 JPL classifies 2006 MB as an Amor and calculates an Earth MOID of 0.061231 AU (23.83 LD), and reports this object passed Earth at 27.2 LD on 4 June 2006. Observations are reported from the following observatories in MPEC 2006-O02: Andrushivka Obs. [A50] 2006-07-04 2236-2243, 3 pos. in MPEC 2006-O02, follow-up See also information from the week ending 16 July 2006. 2006 OA1 (K06O01A) [ JPL Orbit Viewer | NEODyS object home | news | viewing | index | top ]

Size estimate: 118 meters per JPL H=22.29, MPC H=22.3 JPL classifies 2006 OA1 as an Apollo and calculates an Earth MOID of 0.099767 AU (38.82 LD). Observations are reported from the following observatories in MPEC 2006-O08: Siding Spring Survey (SSS) [E12] 2006-07-18 1317-1401, 4 pos. in MPEC 2006-O08, discovery (*) 2006-07-18 1517-1724, 8 pos. in MPEC 2006-O08, confirmation 2006-07-18 1907-1930, 6 pos. in MPEC 2006-O08, confirmation 2006-07-19 1624-1639, 3 pos. in MPEC 2006-O08, confirmation 2006-07-20 1536-1553, 4 pos. in MPEC 2006-O08, confirmation 2004 XP14 (K04X14P) [ JPL Orbit Viewer | NEODyS object home | news | viewing | index | top ]

Size estimate: 467 meters per JPL H=19.30, MPC H=19.4 -- not small This object was listed from 11 Dec. 2004 until 17 March 2005 as an impact risk. JPL classifies 2004 XP14 as an Apollo and calculates an Earth MOID of 0.002495 AU (0.97 LD), and reports this object passed Earth at 1.1 LD on 3 July 2006 at 0426 UT. Observations are reported from the following observatories in MPEC 2006-O02: Crimean Astrophysical Obs. [095] 2006-07-03 1831-1854, 27 pos. in MPEC 2006-O04, follow-up 2006-07-03 2031-2058, 41 pos. in MPEC 2006-O04, follow-up 2006-07-03 2232-2254, 34 pos. in MPEC 2006-O04, follow-up 2006-07-04 0034-0106, 47 pos. in MPEC 2006-O04, follow-up 2006-07-04 2341-2355, 21 pos. in MPEC 2006-O04, follow-up Kiev comet station [585] 2006-07-03 2119-0002, 9 pos. in MPEC 2006-O04, follow-up See also information from the week ending 16 July 2006.

48+120 Hours [ Objects Listings (size order) | Object Index (alpha/xref) | top ]

Observations of four small objects were reported during the last 168 hours: 2006 MB, 2006 OA1, 2006 OK3 & 2006 OY4, plus 2004 XP14 in MPECs: 2006-O02 time-stamped 2006 July 17, 06:07 UT - Daily Orbit Update 2006-O04 time-stamped 2006 July 18, 06:06 UT - Daily Orbit Update 2006-O08 time-stamped 2006 July 20, 16:39 UT - 2006 OA1 2006-O22 time-stamped 2006 July 22, 20:08 UT - 2006 OK3 2006-O26 time-stamped 2006 July 23, 03:46 UT - 2006 OK3 2006-O28 time-stamped 2006 July 23, 03:51 UT - 2006 OY4 Date & times for other sources that were parsed to compile this page: JPL Close Approaches, downloaded at 2006 July 23, 1806 UTC JPL NEO Orbital Elements, downloaded at 2006 July 23, 1811 UTC Lowell Observatory Orbit intersections, time-stamped 2006 Jul 23 1730:51 UTC MPC NEA.DAT from MPC mirror, downloaded at 2006 July 23, 1806 UTC Risk monitoring sites, as of A/CC's check at 2006 July 23, 1512 UTC (see CRT page) Some observation sets have MPEC codes in parentheses, such as (*) denoting discovery.

Viewing Opportunities for Small Objects [ news | size order | alpha order | top ]

This compilation shows 11 small objects as being currently in view, including 7 not reported in the last seven days. Viewing by date order - see this list also by designation order Object View until MOID AU Dia H Arc Notes (calc date) ---------- ---------- -------- --- ----- --- - ----------------------- 2006 MY1 2006-07-24 0.147149 116 22.33 7 - past obs. - (27 June) 2006 OK3 2006-07-24 0.000834 13 27.12 0 - was risk listed - (23 July) 2006 KJ89 2006-07-28 0.092211 58 23.85 7 - past obs. - (1 July) 2006 MB 2006-07-31 0.061231 105 22.55 28 - (16 July) 2006 KM89 2006-08-01 0.146410 62 23.67 22 - past obs. - (21 June) 2006 OA1 2006-08-09 0.099767 118 22.29 2 - (20 July) 2006 MH10 2006-09-01 0.124765 122 22.22 23 - past obs. - (16 July) 2006 KK103 2006-09-01 0.139955 110 22.44 50 - past obs. - (16 July) 1999 LK1 2006-09-11 0.027549 128 22.11 14 - faint recov. poss. - (30 April) 2006 OY4 2006-10-03 0.087408 67 23.53 2 - (23 July) 1998 HG49 2006-12-21 0.076404 141 21.91 3op - "only 1 night" - past obs. - (16 July) Viewing by designation order - see also Viewing by date order Object View until MOID AU Dia H Arc Notes (calc date) ---------- ---------- -------- --- ----- --- - ----------------------- 2006 OY4 2006-10-03 0.087408 67 23.53 2 - (23 July) 2006 OK3 2006-07-24 0.000834 13 27.12 0 - was risk listed - (23 July) 2006 OA1 2006-08-09 0.099767 118 22.29 2 - (20 July) 2006 MH10 2006-09-01 0.124765 122 22.22 23 - past obs. - (16 July) 2006 MY1 2006-07-24 0.147149 116 22.33 7 - past obs. - (27 June) 2006 MB 2006-07-31 0.061231 105 22.55 28 - (16 July) 2006 KK103 2006-09-01 0.139955 110 22.44 50 - past obs. - (16 July) 2006 KM89 2006-08-01 0.146410 62 23.67 22 - past obs. - (21 June) 2006 KJ89 2006-07-28 0.092211 58 23.85 7 - past obs. - (1 July) 1999 LK1 2006-09-11 0.027549 128 22.11 14 - faint recov. poss. - (30 April) 1998 HG49 2006-12-21 0.076404 141 21.91 3op - "only 1 night" - past obs. - (16 July) Out-of-view date based on MPES solar elongation <40° and/or magnitude V>22.0 at 1200 UT geocentric. (Not factored in is any lunar interference with viewing.) Objects are linked in the left-most column only if observed in the last seven days, while objects with earlier small-object reporting are linked under "Notes." Diameter ("Dia") is in meters, a very rough estimate from brightness (H). Observing "Arc" is from MPES in days or number of oppositions. "In view" does not necessarily mean locatable for objects with short arcs in prior years and for which a large search or accidental rediscovery are the best hopes.

Small object observation cross index [ size order | 48 Hours | viewing | top ]

Object

Observed by MPC code

095, 585

A50

E12

E12, I77, J95