Thursday29 January 200411:53pm MST2004-01-30 UTC 0653 back top next  

The Asteroid/Comet Connection's
daily news journal about
asteroids, comets, and meteors


Today's issue status: done
yesterdayJanuarytomorrowIndex
  • Small objects – for 19-25 January
  • News briefs – meteorite chemistry, Stardust, cover details, readings & Hubble reprieve?
  • Risk monitoring–NEODyS has posted 2004 BE68 & removed 2004 BU58 while JPL has removed 2004 BV1 & BO41 plus late news: JPL has added 2004 BA75 & removed 2004 BW58

Cover image: You probably didn't know that Polaris Industries makes asteroid sample return vehicles, but here's proof of it from Robert Verish, a photo from last October showing two meteorites recently found in northern Nevada (with coin and cubic centimeter scale). See "News briefs: Cover details" below for more about this picture from his Nevada Meteorite Picture site, which is used with permission.

Small objects – part 1/4 Major News for 29 Jan. 2004 back top next  
A fictitious 23-meter asteroid with a 2-meter astronaut stick figure for scale.

Small objects     Discoveries & follow-up during 19-25 January

Last week a Spacewatch and University of Arizona news release said:

Astronomers want to study small asteroids to know how many there are, their spin rates and surface properties. . .  Spin rate tells observers if the asteroid is a single solid piece or a loose aggregate of rocks. The distribution of asteroid sizes tells scientists about the effects of asteroid collisions during the lifetime of the solar system. The smallest asteroids are free of regoliths, the blanket of loose dust or dirt that obscures the bare rock surfaces of larger asteroids. And the smallest asteroids are useful for studying non-gravitational forces that work on very long time scales, such as the Yarkovsky Effect, a phenomenon where heat propels objects through space. 

Twenty new-found near-Earth asteroids (NEAs) were announced last week. Twelve have absolute absolute magnitude (H) around or greater than 22.0, and three others of like size were tracked. This summary report is in size order, smallest first. Magnitudes are from JPL DASTCOM, MOIDs (minimum orbital intersection distances) are from Lowell Observatory, diameters are best estimates from a standard but very inexact H-to-size formula, and data is from January 25th. Object attributes are subject (and likely) to change.

2004 BV18
Est. diameter: 23 meters
Abs. mag. H = 25.84 (JPL)
Earth MOID: 0.01188 AU

NEW:  2004 BV18 was both the smallest asteroid discovered last week and last week's biggest asteroid news. See A/CC's article, cover, and follow-up report. It was discovered on 19 Jan. with the Spacewatch 0.9m telescope with volunteer online help, was confirmed on 20 Jan. by Obs. Astronomico de Mallorca (OAM), Hope Obs., and Powell Obs., and was announced 20 Jan. in MPEC 2004-B23.

2004 BV18 was reported this last week as observed on 20 Jan. by Table Mountain Obs., Robert Hutsebaut/New Mexico Skies, and Sormano Obs., on 21 Jan. by the Spacewatch 0.9m telescope and Consell Obs., on 22 Jan. by LINEAR, on 23 Jan. by KLENOT, on 24 Jan. by LINEAR and Great Shefford Obs., and on 25 Jan. by Great Shefford.

2004 BV18's orbit would classify it as potentially hazardous if its physical size was larger. It also has a Mars MOID of 0.033 AU.

Small objects – part 2/4 Major News for 29 Jan. 2004 back top next  
2004 BN41
Est. diameter: 33 meters
Abs. mag. H = 25.08 (JPL)
Earth MOID: 0.01000 AU

NEW:  2004 BN41 was discovered on 23 Jan. by LINEAR, was confirmed on 24 Jan. by KLENOT and Table Mountain Obs., and was announced in MPEC 2004-B39 of 24 Jan. JPL posted it on the 24th with a single impact solution. It has a Mars MOID of 0.022 AU.

2004 BG41
Est. diameter: 36 meters
Abs. mag. H = 24.84 (JPL)
Earth MOID: 0.01354 AU

NEW:  2004 BG41 was discovered on 22 Jan. by LINEAR, was confirmed on 23 Jan. by Table Mountain Obs., Powell Obs., and KLENOT, and was announced in MPEC 2004-B36 of 23 Jan. It was reported this last week as observed on 24 Jan. by Great Shefford.

2004 AE6
Est. diameter: 41 meters
Abs. mag. H = 24.61 (JPL)
Earth MOID:

2004 AE6 was reported this last week as observed on 19 Jan. by Jornada Obs. and on 23 Jan. by KLENOT. 2004 AE6 was discovered on 15 Jan. with the Spacewatch 0.9m telescope and announced in MPEC 2004-B04 of 17 Jan. It has a Mars MOID of 0.028 AU.

2004 AD
Est. diameter: 43 meters
Abs. mag. H = 24.48 (JPL)
Earth MOID: 0.02489 AU

2004 AD was reported this last week as observed on 19 Jan. by LINEAR. It was discovered on 4 Jan. by LONEOS and announced in MPEC 2004-A23 of 5 Jan. It was an A/CC "cover" subject on January 8th and 11th.

2004 BY1
Est. diameter: 43 meters
Abs. mag. H = 24.46 (JPL)
Earth MOID: 0.02084 AU

NEW:  2004 BY1 was discovered on 17 Jan. with NEAT's Haleakala telescope, was confirmed on 17 Jan. by Ondrejov Obs. and on 18 Jan. by Great Shefford Obs. and Grasslands Obs., and was announced in MPEC 2004-B10 of 18 Jan. It was reported this last week as observed on 19, 22, and 23 Jan. by Powell Obs., and on 24 Jan. by KLENOT. It was listed by JPL with impact solutions from the 18th until the 20th, and has a Venus MOID of 0.006 AU. See also the January 19th cover

2004 BF11
Est. diameter: 49 meters
Abs. mag. H = 24.19 (JPL)
Earth MOID:

NEW:  2004 BF11 was discovered on 18 Jan. with the Spacewatch 0.9m telescope, was confirmed on 19 Jan. by Powell Obs., the Spacewatch 0.9m telescope, Desert Moon Obs., the Vatican Advanced Technology Telescope (VATT), and Grasslands Obs., and was announced in MPEC 2004-B15 of 19 Jan. It was reported this last week as observed on 24 Jan. by KLENOT. It has a Mars MOID of 0.047 AU.

Small objects – part 3/4 Major News for 29 Jan. 2004 back top next  
2004 BH11
Est. diameter: 51 meters
Abs. mag. H = 24.13 (JPL)
Earth MOID: 0.01736 AU

NEW:  2004 BH11 was discovered on 18 Jan. with the Spacewatch 0.9m telescope, was confirmed on 19 Jan. with the same telescope and by Powell, Desert Moon, and Grasslands observatories, and was announced in MPEC 2004-B17 of 19 Jan. It was reported this last week as observed on 23 Jan. by KLENOT.

2004 BK11
Est. diameter: 106 meters
Abs. mag. H = 22.52 (JPL)
Earth MOID:

NEW:  2004 BK11 was discovered on 18 Jan. with the Spacewatch 0.9m telescope, was confirmed on 19 Jan. with the same telescope and by VATT and Grasslands Obs., and was announced in MPEC 2004-B19 of 19 Jan. It was reported this last week as observed on 19 Jan. by Tenagra II Obs., on 23 Jan. by Linz Obs., and on 24 Jan. by KLENOT.

2004 AD1
Est. diameter: 113 meters
Abs. mag. H = 22.38 (JPL)
Earth MOID: 0.02859 AU

2004 AD1 was reported this last week as observed on 18 Jan. by Begues Obs., on 21 Jan. by LINEAR and Consell Obs., and on 24 Jan. by LINEAR. 2004 AD1 was discovered on 13 Jan. by LONEOS and announced in MPEC 2004-A53 of 14 Jan.

1999 AJ39
Est. diameter: 122 meters
Abs. mag. H = 22.21 (JPL)
Earth MOID:

NEW:  1999 AJ39 was caught on 19 Jan. by the Spacewatch 0.9m telescope and quickly confirmed by Grasslands Obs., following which this object was linked with an object observed with the same 0.9m telescope on 15, 16, and 19 Jan. 1999. This was announced on 19 Jan. 2004 in MPEC 2004-B22.

2004 BW18
Est. diameter: 129 meters
Abs. mag. H = 22.10 (JPL)
Earth MOID: 0.04553 AU

NEW:  2004 BW18 was discovered on 19 Jan. by LINEAR and confirmed 20 Jan. by McCarthy Obs., OAM, Powell Obs., Hope Obs., Table Mtn. Obs., and Sabino Canyon Obs., and was linked with LINEAR 30 Dec. observations, then announced 20 Jan. in MPEC 2004-B24. It was observed on 20 Jan. by LINEAR and Sormano Obs., on 21 Jan. by LINEAR, on 22 Jan. by Rodeno Obs. and LINEAR, on 23 Jan. by KLENOT and Rezman Obs., and on 24 Jan. by Begues Obs. The MPC had H=22.5.

NEW:  2004 BM11
Est. diameter: 150 meters
Abs. mag. H = 21.77 (JPL)
Earth MOID:

NEW:  2004 BM11 was discovered on 18 Jan. by NEAT/Palomar and was confirmed on 18 Jan. by Gnosca Obs. and on 19 Jan. by Powell Obs. and Grasslands Obs., and was announced in MPEC 2004-B21 of 19 Jan. 2004 BM11 was reported this last week as observed on 19 Jan. by LINEAR, on 22 Jan. by Powell Obs. and Crni Vrh Obs., and on 25 Jan. by Great Shefford Obs. It has MOIDs of 0.014 AU with Venus and 0.037 AU with Mars. On 25 Jan., the MPC had H=22.2.

Small objects – part 4/4 Major News for 29 Jan. 2004 back top next  
2004 BJ11
Est. diameter: 153 meters
Abs. mag. H = 21.73 (JPL)
Earth MOID:

NEW:  2004 BJ11 was discovered 18 Jan. with the Spacewatch 0.9m telescope and confirmed on 19 Jan. with that telescope and by Powell Obs. and Grasslands Obs., and was announced in MPEC 2004-B18 of 19 Jan. with H=22.1. Powell Obs. also caught it 22 Jan.

2004 BT58
Est. diameter: 156 meters
Abs mag H = 21.69 (JPL)
Earth MOID:

NEW:  2004 BT58 was discovered 23 Jan. by LINEAR, was confirmed on 23 Jan. by Starkenburg Obs., Modra Obs., and KLENOT, and on 24 Jan. by Table Mountain Obs., LINEAR, and KLENOT, and was announced in MPEC 2004-B44 of 25 Jan. with H=22.1.

EasySky screen grabs of known H>22.0 asteroids on 25 Jan. Those observed last week are circled with ID and orbit.

Known small asteroids (green dots) on 25 Jan. 2004
Ecliptic grid set at 20 lunar distances
News briefs – part 1/1 Major News for 29 Jan. 2004 back top next  
News briefs

Hubble reprieve?  Sky & Telescope has a report today, "Hubble Gets a Reprieve":

[Sean] O'Keefe has now agreed to reconsider his decision to abandon Hubble. In a letter sent to [Sen. (D-MD) Barbara] Mikulski yesterday, the NASA administrator wrote, "I have asked Admiral Hal Gehman, Chair of the Columbia Accident Investigation Board, to review the matter and offer his unique perspective." 

See also Space.com and AP reports.

Meteorite chemistry:  Argonne National Laboratory (ANL) has a news release today that tells briefly about how scientists "examined stardust from a meteorite and found remnants of now-extinct technetium atoms made in stars long ago." The "signature of live technetium — an element that has no stable isotopes — [is observed] in the starlight from certain types of stars."

Stardust:  JPL has posted a video of mission navigator Dr. Shyam Bhaskaran giving a preview of the navigation know-how involved in Stardust's successful comet 81P/Wild 2 encounter.

Cover details:  Robert Verish tells A/CC today that "I just received the classification back from the lab for the chondrite on the right [above]: H4. It is my experienced opinion that the chondrite on the left is paired to the one on the right, based on a number of factors (their proximity being the least significant). The names of the finders and the location will be made public when the Meteoritical Bulletin is published this year or next."

Readings:  An Associated Press wire story appears on many news sites today, including CNN and USA Today, about last week's Spacewatch FMO Project volunteer news. See A/CC's reports of the 20th and 21st.

National Geographic has an article today, "Scientists Plan 'Deep Impact' Crash With Comet," about the NASA/JHU-APL Deep Impact mission.

The Haddon, Penn. Herald has an article telling about "The Bizarre Baobab." A truly enormous tree in the wild, its seeds can be grown into an unusual bonsai project (see here and here, for instance). Great for the NEO observer, minor object scientist, or future asteroid occupant who has everything.

Risk monitoring - part 1/2 Major News for 29 Jan. 2004 back top next  
Risk monitoring 29 Jan.

NEODyS has posted 2004 BE68, which was announced yesterday in MPEC 2004-B59 as discovered by LINEAR early Tuesday UT in New Mexico and confirmed yesterday morning by Sandlot Observatory in Kansas and by Three Buttes, Tenagra II, and Sabino Canyon observatories in Arizona. And there are addititional observations from LINEAR in today's Daily Orbit Update MPEC (DOU). The European Spaceguard Central Node (SCN) today posted an observing campaign for this object, estimated at "700-800 meters in size," noting "observations should not be difficult" and that "all the VIs" might be removed easily.

Today's DOU has 2004 BV1 observations from the Spacewatch 1.8m telescope in Arizona early yesterday, and today JPL removed its last impact solutions for this object and SCN retired its observing campaign. 2004 BV1 previously had been noted by SCN to go out of view for most observers on the 23rd. It was caught on the morning of the 25th by Jornada Observatory and that night by the 2.5m Isaac Newton Telescope (INT) at La Palma in the Canary Islands.

Summary Risk Table - sources checked at 0631 UTC, 30 Jan

Object

Assessment

Years

VI
PS
cum
PS
max
T
S
Arc 
days
 2004 BW58JPL 1/30R E M O V E D
 2004 BV1JPL 1/29R E M O V E D
NEODyS 1/27R E M O V E D
 2004 BU58NEODyS 1/29R E M O V E D
 2004 BO41JPL 1/29R E M O V E D
 2004 BN41JPL 1/292098-20981-6.64-6.6405.036
 2004 BE68 NEODyS 1/292005-2080174-3.64-4.4501.129
 2004 BA75JPL 1/302008-206610-7.23-7.5902.217
 2003 YG118JPL 1/252087-20871-4.02-4.02037.665
NEODyS 12/31R 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.

The DOU has observations of 2004 BO41 from early yesterday from Tenagra II and the Spacewatch 1.8m telescope, and today JPL removed its single impact solution for this kilometer-plus object.

2004 BU58 is in the DOU from Tuesday morning from Kingsnake Observatory in Texas, from yesterday morning from the INT on La Palma and Tenagra II,

more Risk monitoring >>

Risk monitoring - part 2/2 Major News for 29 Jan. 2004 back top next  

<< continued from part 1

and from last night from Great Shefford Observatory. Today NEODyS removed its impact solutions for this object and SCN retired its observing campaign.

The DOU has observations of 2004 BN41 from yesterday morning from the Spacewatch 1.8m telescope, and today JPL very slightly lowered its low-rated assessment for this small object.

2004 BW58 is reported in today's DOU from yesterday morning from the Spacewatch 1.8m and Tenagra II.

SCN today pulled 2003 YG118 from its Priority List. It hasn't been reported seen since the 23rd, but was last noted as being in view until May 1st.

Late update:  Thursday evening in Pasadena, JPL has removed 2004 BW58 and has posted 2004 BA75, a small object that was announced late on Thursday UT in MPEC 2004-B64. The JPL risk assessment is quite low overall, and it is too small to be categorized as "potentially hazardous," but it's interesting to note that the first of JPL's highly preliminary impact solutions for this Spacewatch discovery is only four years away.

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