2 May '04 Major News about Minor Objects

Major News for 2 May 2004

Small objects
Discovery & follow-up 26 April–2 May

Despite the brightening Moon, six new small object discoveries were announced last week, another nine were tracked from Sunday through yesterday (three with impact solutions), and observations were reported for two more from earlier in April. (A "small" object is defined here as having absolute magnitude H=22.0 or greater, which converts inexactly to a diameter of 135 meters/yards or less.)

Twenty-eight observing facilities participated in this work, with Powell Observatory in Kansas catching the most (seven). Four of the discoveries were made by LINEAR in New Mexico, and one each was made from Arizona with the Spacewatch 0.9m telescope and by the Catalina Sky Survey.

The smallest discovery, and smallest observed this week, is 2004 HT59, which is roughly estimated at a dozen meters/yards wide. And, according to the JPL Close Approaches page, the closest known flyby last week was made by that same object, on Monday at

2.7 lunar distances (LD). The next closest, by 2004 HS56, was yesterday at 14.1 LD, and 2004 HH20 came to 14.5 LD on Wednesday. The closest flyby predicted for a small object this next week will be 2004 HX53 at 12.5 LD on Friday.

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If an asteroid's orbit brings it to within 0.05 AU of Earth's orbit, it is categorized as "potentially hazardous" unless it has an absolute magnitude H greater than 22.0, which corresponds to a diameter on the order of 135 meters/yards. Larger H is dimmer, thus smaller. And 0.05 astronomical units (AU) is about 19.5 times the distance between Earth and Moon (0.00256 AU).

Notes: Diameters in the following observation summary table are rough best estimates from a standard but very inexact H-to-size formula using H (absolute magnitude) from the JPL NEO Orbital Elements page, source also for Earth MOID (minimum orbital intersection). Other planetary MOIDs are from Lowell Observatory. Current Minor Planet Center H is also given, along with the original H from each object's discovery MPEC. Priorities and visibilities are from the European Spaceguard Central Node (SCN).

Small objects – panel 2/2 (table)

Major News for 2 May 2004

Small object observation summary for 26 April–2 May

H = absolute magnitude (brightness), from which size is roughly estimated — m/yd = meters/yards — [cross index]
All objects had observations reported last week. Those on a light-blue background had observations from only before the week.

Object	Estimated diameter	JPL H	MPC H	Discovery H in MPEC	Earth MOID	European Spaceguard Central Node priority/visibility/campaign
2004 HT59 Aten	12 m/yd	27.33	27.2	27.0 2004-H86	0.00634 AU
2004 HT59 Aten	NEW: 2004 HT59 was discovered on 24 April by LINEAR, was confirmed on 25 April by the Southern Sky Survey (SSS), and was announced in MPEC 2004-H86 of 29 April. It was also observed 25 April by LINEAR. It passed Earth at 2.7 LD on the 26th and hasn't been reported since.
2004 HC33 Apollo	22 m/yd	25.94	26.0	25.8 2004-H60	0.01755 AU
2004 HC33 Apollo	2004 HC33 was observed on 24 April with the Spacewatch 1.8m telescope, on 25 April by Great Shefford Obs. (see "cover" image above), and on 27 April by Powell Obs.
2004 HH20 Amor	34 m/yd	24.98	25.1	24.7 2004-H51	0.03016 AU	Urgent, visibility ends 17 May
2004 HH20 Amor	2004 HH20, which passed Earth at 14.5 LD on 28 April, was observed on the 25th by Mt. John Obs.
2004 HD Amor	40 m/yd	24.65	24.8	24.5 2004-H19	0.03048 AU	Useful, visibility ends 6 Jun.
2004 HD Amor	2004 HD was observed on 25 April by the Catalina Sky Survey (CSS) and Hunters Hill Obs.
2004 GD2 Apollo	52 m/yd	24.08	24.3	24.2 2004-G28	0.02000 AU	Useful, visibility ends 7 Jun.
2004 GD2 Apollo	2004 GD2 was observed on 25 April by Hunters Hill Obs. It has an MOID of 0.001 AU with Mars.
2004 GC19 Apollo	52 m/yd	24.06	24.1	24.1 2004-H06	0.03505 AU
2004 GC19 Apollo	2004 GC19 was observed on 25 April by Great Shefford Obs. See "cover" image April 29th, and Peter Birtwhistle's 2004 GC19 page.
2004 EU22 Apollo	62 m/yd	23.68	23.7	23.7 2004-F22	0.00801 AU	Useful, visibility ends 25 May
2004 EU22 Apollo	2004 EU22 was reported this last week as observed on 2 April by Pulkovo Obs.
2004 HT38 Amor	71 m/yd	23.39	23.5	23.6 2004-H71	0.09863 AU	Necessary, visibility ends 31 May
2004 HT38 Amor	NEW: 2004 HT38 was discovered on 24 April by LINEAR, was confirmed on 24 April by Consell Obs., and on 25 April by Great Shefford Obs., Sabino Canyon Obs., Desert Moon Obs., and Mt. John Obs., and was announced in MPEC 2004-H71 of 25 April. This object was also observed on 25 April by Mt. John Obs., on 27 April by Powell Obs., on 28 April by NEAT/Haleakala, and on 30 April by Tenagra II Obs.
2004 HR56 Apollo	75 m/yd	23.28	23.3	23.3 2004-H82	0.06039 AU	Urgent, visibility ends 10 May
2004 HR56 Apollo	NEW: 2004 HR56 was discovered on 25 April with the Spacewatch 0.9m telescope, was confirmed on 27 April by Andrushivka Obs. and Obs. Astronomico de Mallorca (OAM), and on 28 April by Drebach Obs., Powell Obs., and Sabino Canyon Obs., and was announced in MPEC 2004-H82 of 28 April, but hasn't been reported since. It has an MOID of 0.024 AU with Mars.
2004 HQ1 Apollo has VI	78 m/yd	23.19	23.0	23.0 2004-H38	0.00230 AU	Necessary, visibility ends 3 Jun.
2004 HQ1 Apollo has VI	2004 HQ1 was observed on 25 April by Hunters Hill Obs. and Sormano Obs., on 27 April by Powell Obs., and on 28 April with the 2.5m Isaac Newton Telescope (INT) at La Palma and by David Tholen's team at the Univ. of Hawaii 2.2m Telescope.
2004 HM Apollo has VIs	83 m/yd	23.05	23.2	23.3 2004-H25	0.00338 AU	Necessary, visibility ends 22 May
2004 HM Apollo has VIs	2004 HM was observed on 25 April by Pla D'Arguines Obs. and Sandlot Obs., on 26 April by LINEAR, and on 27 April by Sandlot Obs.
2004 HX53 Apollo	87 m/yd	22.96	23.6	23.8 2004-H80	0.02080 AU
2004 HX53 Apollo	NEW: 2004 HX53 was discovered on 26 April by LINEAR, was confirmed on 26 April by OAM, and on 27 April by Powell Obs. and Sabino Canyon Obs., and was announced in MPEC 2004-H80 of 27 April. This object was also observed on 27 April by LINEAR and Consell Obs., on 30 April by Table Mountain Obs., and on 1 May by Tenagra II Obs. This object, which will pass Earth at 12.5 LD on 7 May, has an MOID of 0.050 AU with Mars.
2004 GB19 Apollo	90 m/yd	22.88	23.0	22.7 2004-H04	0.01060 AU	Necessary, visibility ends 25 May
2004 GB19 Apollo	2004 GB19 was reported this last week as observed on 24 April by Pla D'Arguines Obs. It has an MOID of 0.011 AU with Mars.
2004 HB39 Amor	103 m/yd	22.58	22.6	22.5 2004-H74	0.09266 AU	Useful, visibility ends 17 Aug.
2004 HB39 Amor	NEW: 2004 HB39 was discovered on 25 April by CSS, was confirmed 25 April by Starkenburg Obs. and 26 April by Table Mountain Obs., and was announced in MPEC 2004-H74 of 26 April. This object was also observed on 28 April by Powell Obs. and on 1 May by Tenagra II Obs.
2004 HZ Apollo has VIs	122 m/yd	22.21	22.7	22.8 2004-H34	0.00003 AU	Urgent, visibility ends 7 May
2004 HZ Apollo has VIs	2004 HZ was observed on 25 April by Jornada Obs. and Sormano Obs., on 29 April with the INT at La Palma, and on 1 May by Jornada Obs. and the Spacewatch 1.8m telescope.
2004 HS56 Amor	133 m/yd	22.03	22.2	22.0 2004-H83	0.03047 AU	Necessary, visibility ends 26 May
2004 HS56 Amor	NEW: 2004 HS56 was discovered on 27 April by LINEAR, was confirmed on 27 April by Andrushivka Obs. and OAM, and on 28 April by Drebach Obs., Powell Obs., and Sabino Canyon Obs., and was announced in MPEC 2004-H83 of 28 April. It was also observed on 28 April by LINEAR, Table Mountain Obs., Francisquito Obs., and University Hills Obs., on 30 April by Robert Hutsebaut via New Mexico Skies, and on 1 May, the day this object passed Earth at 14.1 LD, by Tenagra II Obs.
2004 HG12 Apollo	137 m/yd	21.97	22.4	22.9 2004-H47	0.02605 AU	Urgent, visibility ends 8 May
2004 HG12 Apollo	2004 HG12 was observed on 27 April by Table Mountain Obs.

Small object observation cross index [table top]

Object	Observed by MPC code
2004 EU22	084
2004 GB19	941
2004 GC19	J95
2004 GD2	E14
2004 HB39	611, 649, 673, 703 & 926
2004 HC33	291, 649 & J95
2004 HD	703 & E14
2004 HG12	673
2004 HH20	474
2004 HM	704, 941 & H36
2004 HQ1	568, 587, 649, 950 & E14
2004 HR56	113, 620, 649, 691, 854 & A50
2004 HS56	113, 620, 649, 673, 704, 854, 926, A50, G70, G72 & H06
2004 HT38	448, 474, 608, 649, 854, 926 & J95
2004 HT59	704 & E12
2004 HX53	176, 620, 649, 673, 704, 854 & 926
2004 HZ	291, 587, 715 & 950

Code	Observatory	Objects observed (days)
084	Pulkovo Obs.	2004 EU22
113	Drebach Obs.	2004 HR56 & 2004 HS56
176	Consell Obs.	2004 HX53
291	Spacewatch 1.8m telescope	2004 HC33 & 2004 HZ
448	Desert Moon Obs.	2004 HT38
474	Mt. John Obs.	2004 HH20 & 2004 HT38(2)
568	U. Hawaii 2.2m Tel./Tholen team	2004 HQ1
587	Sormano Obs.	2004 HQ1 & 2004 HZ
608	NEAT/Haleakala	2004 HT38
611	Starkenburg Obs.	2004 HB39
620	Obs. Astron. de Mallorca	2004 HR56, 2004 HS56 & 2004 HX53
649	Powell Obs.	2004 HB39, 2004 HC33, 2004 HQ1, 2004 HR56, 2004 HS56, 2004 HT38 & 2004 HX53
673	Table Mountain Obs.	2004 HB39, 2004 HG12, 2004 HS56 & 2004 HX53
691	Spacewatch 0.9m telescope	2004 HR56
703	Catalina Sky Survey (CSS)	2004 HB39 & 2004 HD
704	LINEAR	2004 HM, 2004 HS56(2), 2004 HT59 & 2004 HX53(2)
715	Jornada Obs.	2004 HZ(2)
854	Sabino Canyon Obs.	2004 HR56, 2004 HS56, 2004 HT38 & 2004 HX53
926	Tenagra II Obs.	2004 HB39, 2004 HS56, 2004 HT38 & 2004 HX53
941	Pla D'Arguines Obs.	2004 GB19 & 2004 HM
950	2.5m I.N. Telescope, La Palma	2004 HQ1 & 2004 HZ
A50	Andrushivka Obs.	2004 HR56 & 2004 HS56
E12	Southern Sky Survey (SSS)	2004 HT59
E14	Hunters Hill Obs.	2004 GD2, 2004 HD & 2004 HQ1
G70	Francisquito Obs.	2004 HS56
G72	University Hills Obs.	2004 HS56
H06	N.M. Skies/R. Hutsebaut	2004 HS56
H36	Sandlot Obs.	2004 HM(2)
J95	Great Shefford Obs.	2004 GC19, 2004 HC33 & 2004 HT38

Risk monitoring - panel 1/1

Major News for 2 May 2004

Risk monitoring

2 May

The Sunday Daily Orbit Update MPEC (DOU) has observation of 2004 HZ from early yesterday from Jornada Observatory in New Mexico and from the Spacewatch 1.8m telescope in Arizona. Today NEODyS and JPL very slightly raised their overall risk ratings for this small object, which goes out of view in a few days.

The DOU also has positions reported for 2004 HK33 from NEAT's Hawaiian telescope yesterday. Today both risk monitors slightly lowered their risk assessments for this kilometer-size object.

The only other object with impact solutions that is reported in today's DOU is 2004 GA1, which was followed up Friday by Reedy Creek Observatory in Australia, discoverer of this kilometer-size object. Today JPL removed its only impact solution for 2004 GA1.

Summary Risk Table - sources checked at 2159 UTC, 2 May
Object	Assessment	Years	VI	PS cum	PS max	T S	Arc days

2004 HZ	NEODyS 5/2	2023-2045	4	-2.39	-2.39	0	11.973
2004 HZ	JPL 5/2	2023-2033	3	-2.44	-2.44	0	11.973

2004 HW	NEODyS 4/29	2016-2045	3	-4.82	-5.13	0	6.891
2004 HW	JPL 4/29	2092-2092	1	-3.50	-3.50	0	6.891

2004 HQ1	NEODyS 4/30	2065-2065	1	-7.57	-7.57	0	9.741
2004 HQ1	JPL 4/30	2065-2065	1	-7.73	-7.73	0	9.741

2004 HM	JPL 4/29	2101-2104	2	-5.05	-5.05	0	10.990

2004 HK33	NEODyS 5/2	2041-2068	6	-2.87	-3.07	0	10.165
2004 HK33	JPL 5/2	2019-2068	7	-2.64	-2.88	0	10.165

2004 HE62	JPL 5/1	2064-2087	2	-5.22	-5.33	0	4.164

2004 GE2	JPL 4/24	2100-2100	1	-6.02	-6.02	0	11.811

2004 GA1	JPL 5/2	R E M O V E D
2004 GA1	NEODyS 4/19	R E M O V E D
VI = count of "virtual impactors" (impact solutions) See A/CC's Consolidated Risk Tables for more and maybe newer details, and check the monitors' links for latest info. Note that only objects recently in view are shown here.