October 2002 Asteroid/Comet News
9 October 2003
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2 October 2002
Reported as probably spacecraft debris, the Associated Press article,
"Sky fireball wows New Zealanders," on CNN 2 Oct. didn't give a date or time, and this event doesn't seem to have received coverage elsewhere.
4 October 2002
The Ondrejov Observatory's NEO Photometric Program News page posted a 4 Oct. note that a light curve has been determined for 1998 RO1 that indicates it is a binary.
6 October 2002
A fireball was observed across southern England just before 6am local time. See "'Meteor' lights up Midlands," 6 Oct. BBC article. In the southwestern U.S., a fireball was observed at 7:22pm local time. See Fireball fiesta below.
7 October 2002
In the southwestern U.S., separate fireballs were observed at 7:18pm local time and about ten minutes later. See Fireball fiesta below.
Precoveries by DANEOPS were announced on the 7th for two objects that only just recently had been listed on the JPL and NEODyS risk pages. 2002 QF15 and 2002 RS28 were discovered on 27 Aug. and 6 Sept. by LINEAR, and were on the risk pages during early Sept. MPEC 2002-T36 now reports a half-dozen observations for 2002 QF15 going back to 23 July 1955, including 1991 and 1993, all at Siding Spring in Australia. MPEC 2002-T37 reports observations of 2002 RS28 by sister 1.2m telescopes at Siding Spring on 10 May 1985 and at Mount Palomar in 1992. Another NEO, 2002 PO34, was also updated in MPEC 2002-T38 with observations going back to March of last year.
9 October 2002
The JPL NEO Program issued a 9 Oct. update on J002E3, saying that a 16 June 2002 precovery image has been found, and that the object has been showing slight orbital changes explained by solar radiation pressure on a spent rocket stage. It is now certain that J002E3 will depart the Earth-Moon system in June 2003 and that there is no possibility of an impact for several decades. In the years ahead J002E3 may be recaptured, but the first opportunity for this will not be until the mid-2040s. Space.com had a 11 Oct. report.
10 October 2002
An 8 Oct. University of Hawaii news release, "University of Hawaii astronomers to develop new telescopes for "killer asteroid" search," said, [The U.S. Air Force Pan-STARRS] is currently conceived of as an array of small telescopes, and sites on either the Big Island or on Maui are being considered [and planned] to become operational in 2006.
Spacewatch posted a 10 Oct. update to progress on its new 0.9m telescope, saying that they "expect to be observing with the complete system" this month.
11 October 2002
The Australian Mundrabilla metallic meteorite was being CT-scanned at NASA's Kennedy Space Center (KSC) to learn more about its unusual alloys according to a KSC 11 Oct. news release. Florida Today had a 17 Oct. report.
12 October 2002
On 11 Oct., NEAT's Palomar telescope picked up an object that was subsequently located in LINEAR images from the 4th and 9th. After further observations from other observatories early on the 12th, the object was announced later that day in MPEC 2002-T76 as P/2002 T4 (NEAT). Within a short time it became known that its orbit matches 54P/de Vico-Swift, a comet that was discovered by Francesco de Vico in Italy on 23 August 1844, and rediscovered by Edward Swift in California in 1894. Even though this comet spends all of its time between Mars and Jupiter, it had not been observed since 1965. It passed perihelion on 25 July this year. For more info, see Cometography's 54P/de Vico-Swift page, the JPL Orbit Viewer, and IAUCs 7991 and 7992.
18 October 2002
UPI's 18 Oct. item, "NASA studies lasers to divert asteroids," says that two scientists at NASA/Marshal and NASA/Langley Space Flight Centers are studying how to use space- or Moon-based lasers to divert asteroids from impact paths.
22 October 2002
First light for Spacewatch's new 0.9m telescope. Its first NEO, a known object, was spotted during testing the next night.
23 October 2002
On 23 October the IAU Minor Planet Center updated its asteroid Discovery Circumstances to include new namings for 74 asteroids, from 13258 Bej (1998 QT12) to 14588 Pharrams (1998 RH73). All are LINEAR discoveries, mostly from the second half of 1998. There were no other changes in the existing information and no new numberings in the update. (The total of numbered objects remained at 48380.)
An MIT news release of 22 October reports that the namings are for the 40 finalists in the 2002 Discovery Channel Young Scientist Challenge (DCYSC) and their teachers [DCYSC news release|student list]. This is the second year that MIT's Lincoln Lab has named asteroids for DCYSC finalists and teachers (MIT 31 October 2001 news release).
Update: In response to a query from A/CC about how it appeared that only 38 DCYSC finalists had been awarded new asteroid namings, Lincoln Laboratory Executive Officer Roger W. Sudbury confirmed on 24 October that "The Ceres Connection program does not make multiple asteroid honors available to repeating finalists or teachers." Brittany Anderson of New Mexico and Russell Burrows of Texas were finalists in 2001 and 2002, and had already had LINEAR-discovered objects named for them a year ago.
24 October 2002
Planetary Science Research Discoveries on 24 Oct. posted another very interesting article about the earliest meteor makings, "The First Rock in the Solar System." This work with the Murchison meteorite, a carbonaceous chondrite from Australia, came out of a high school mentoring program that won international honors, as told in a 21 Sept. 2000 news release from the University of Chicago. Student Rebecca Elsenheimer found an inclusion of corundum (Al2O3), thought to have been the first major mineral to form out of the solar nebula. The new article tells about her mentors, Lawrence Grossman and Steven Simon, finding an aggregate of corundum with the next minerals to form, hibonite (CaAl12O19) and perovskite (CaTiO3). See also a 6 Sept. report.
31 October 2002
Science@NASA marked Halloween by making fun of how 35396 1997 XF11 "briefly scared astronomers." Calling it the "Halloween Asteroid," the article notes that XF11 made an Earth flyby on 31 October at about 25 lunar distances, close enough for radar observation. Space.com repeated the story as "Halloween Asteroid: Familiar Space Rock Glides by Earth Again."
NASA Watch and SpaceRef.com reported 31 Oct. a new paper [142Kb PDF|from] by Keith S. Noll et al. on using the Hubble Space Telescope to observe the binary EKBOs 1997 CQ29 and 2000 CF105.
Satellite for Main Belt asteroid 121 Hermione
121 Hermione is in the outer Main Belt, a member of the Cybele family. It was discovered by James C. Watson at Ann Arbor, Michigan on 12 May 1872, and has been studied in recent years for its orbital characteristics and mass. It is estimated at 209 km. (130 miles) in diameter, and its satellite at about 13 km. (8 miles). See the JPL Orbit Viewer and AstDyS for more info.
Congressional hearing on national NEO policy
The headlines here are presented in newest-first order.
- Ed Grondine citizen's report, 8 Oct. Cambridge Conf. Corresp. (posted 10 Oct.)
Brian Marsden pointed out at the very end of the hearing, they had failed entirely to discuss comets. . . [Everything] had pertained only to asteroids. . . [Using] Hale-Bopp as an example, Marsden estimated that as it currently sits we would have about 2 years to save ourselves.
Fact check: About "2002 MT7," there may be an object with such a designation, but it hasn't appeared in the MPECs or "between the Earth and the Moon." There is a 2002 NT7 that got some attention recently, but it was 2002 MN that made a surprise inside passage.
- "Astronomers Warn Congress About Near-Earth Asteroid Risks," 9 Oct. Sky & Tel. article
- "US general fears asteroid explosion could trigger nuclear war," 4 Oct. Ananova article
Fact check: "He cited an example of an asteroid explosion in August, while Pakistan and India were at full alert over Kashmir." The atmospheric event was 6 June, and the Kashmir crisis subsided before August. See the link below to Worden's prepared text.
- "NASA Study On Asteroid-Searching Technology Due Next June," 4 Oct. Aerospace Daily article
- "Bill could help asteroid watch," UPI wire 4 Oct. (more on the bill)
- "Threat of asteroids worries lawmakers," 4 Oct. Orlando Sentinel article
[Tracking] smaller objects, developing a defense system and beefing up detection of interplanetary interlopers will cost money and neither NASA nor the military is clamoring to come up with the cash. . . Whether it's NASA, the Air Force or the National Science Foundation that finally takes the reins, Rep. Bart Gordon, D-Tenn., said, someone should step in.
- "Congress contemplates asteroid threat," Gannett wire on Fla. Today 4 Oct.
- "General: Asteroid could start nuke war," 3 Oct. CNN article
- "Could meteor touch off nuclear fear?, Reuters wire on MSNBC 3 Oct.
- "Earth playing cosmic roulette with asteroids," U.S. House Science Comm. 3 Oct. news release
- "Asteroid-Hunting Telescope Proposed at Congressional Hearing," 3 Oct. Space.com article
- Prepared statements from hearing witnesses, in the order given by the committee:
- David Morrison, NASA Ames Research Center
- Edward Weiler, NASA Assoc. Administrator for Space Science
NASA is a space agency. [We] do not feel that we should play a role in any follow-on search and cataloging effort unless that effort needs to be specifically space-based in nature. . . I feel that it is premature to consider an extension of our current national program to include a complete search for smaller-sized NEOs.
- Brian Marsden (71Kb PDF), Dir., IAU Minor Planet Center
- Simon P. Worden, Deputy Dir. for Operations, U.S. Strategic Command (includes former U.S. Space Command, see AP wire on CNN 2 Oct.)
What is needed are in situ measurements across the many classes of NEOs, including asteroids and comets. . . [With] the emergence of so-called "microsatellites," which weigh between 50-200 kg and can be launched as almost "free" auxiliary payloads on large commercial and other flights to GEO orbit. . . missions can be prepared in one to two years for about $5-10M, and launched for a few million dollars as an auxiliary payload.
- Joseph A. Burns, NRC Solar System Exploration Survey Comm.
Systematically building an inventory of the Near-Earth Objects is crucial to an improved understanding of Earth's environment. . . It is also a necessary first step towards a rational program of NASA's exploration of these bodies with spacecraft.
- "Cornell astronomer tells Congress it should spend $125 million for new telescope to detect Earth-threatening asteroids," Cornell 3 Oct. news release
- "Threat from the heavens Who is responsible for protecting Earth from asteroids?" U.S. House Science Comm. news item (3 Oct.)
- "The Threat of Near-Earth Asteroids," U.S. House Science Comm. hearing charter (3 Oct.)
The Air Force is also developing the Panoramic Optical Imager (Pan Starrs) telescope facility in Hawaii that could be operational in four years and could potentially search the entire sky every few days, detecting objects nearly 100 times fainter than the best existing NEO search telescopes.
- Further resources
- U.S. House of Representatives Committee on Science
- Proposed Large-aperture Synoptic Survey Telescope (LSST)
- See a peripherally related news item below about a Congressional act that would reward U.S. amateur NEO efforts.
Charles "Pete" Conrad Astronomy Awards Act
If the Charles "Pete" Conrad Astronomy Awards Act becomes law, it will award prizes out of NASA funds to U.S. citizens in the areas of NEO discovery, follow-up, and cataloging, totalling $10,000 for each of the years 2003 and 2004. Because this bill just came out of the same House committee that held the NEO hearings on the 3rd (see report above), it received attention alongside major NEO issues.
Note: Four NEOs have been discovered by amateurs in the last nine months. Two in Europe, and two in the U.S. by William K. Yeung, who is a citizen of Canada. Congress could more effectively spend such tiny funding by including amateurs everywhere, including countries where a few dollars go a lot further, and especially Australia and elsewhere in the southern hemisphere where only a few lonely amateur efforts cover the half of the sky where NEOs roam mostly unwatched.Ed.
Update: Actually, six NEOs were discovered during 2002, as A/CC has tallied, including one after the above news report. Of the seven discoverers, at least five were not U.S. citizens.
23 EKBOs discovered 12-15 August
MPEC 2002-T26 of 6 Oct. debuted seven EKBOs discovered with the 4m Blanco telescope at Cerro Tololo by a team consisting of Holman, Kavelaars, Grav, and Fraser. The objects were discovered on 12 Aug. except for one on the 13th, and the last follow-up work reported was on Aug. 15th, all using the same instrument. They have semimajor axes initially calculated as between 43.16 and 45.66 AU. MPEC 2002-T43 of 8 Oct. announces nine more such objects discovered in this effort with semimajor axes running from 43.61 to 46.58 AU. All the observations were on 13 and 15 Aug., with the 15th given as the discovery date in every case. MPECs 2002-T60 and 2002-T62 of 10 Oct., and 2002-T68 of 11 Oct., announce another seven such objects discovered in the same effort during 13-15 Aug.
Reconstituting pulverized asteroids
An article in the 12 Oct. New Scientist, "Building in space using waves," reports Narayanan Komerath's proposal to NASA's Institute of Advanced Concepts (NIAC) to use focused radio waves as force fields to build large structures in space with minimal human labor. "Given a few months to do the job [electromagnetic radiation] should be able to assemble rocks, brick-sized or bigger, into any given shape. . .  As a demonstration, he suggests sending a squad of solar-powered radio transmitters to [near-Earth asteroids] and blasting one of the rocks into small pieces [to be shaped into a structure]. Individual parts could be fused together using focused sunlight or a more conventional adhesive, forming a space where astronauts could live and work shielded from radiation."
NIAC has an abstract of Komerath's NASA-funded Phase I study, "Tailored Force Fields for Space-Based Construction," which concludes 31 Oct. 2002. Using both electromagnetic and acoustic shaping, it says "a 2km diameter radiation shield can be built at the Earth-Moon L-2 Lagrangian point using lunar materials," and proposes "pulverizing carbonaceous asteroids and reconstituting a spaceship structure from pulverized material at the Earth-Sun L-5 point." (The Earth-Moon L2 point is opposite the far side of the Moon, and the Earth-Sun L5 point is in the Earth's orbit, trailing the Earth at 60°, a place where there may already be some asteroidal material waiting to work with see Club 1AU.)
Update #1: To get an idea of why creating structures from heavy materials away from Earth is of concrete importance and not just a matter of futuristic theorizing, see two 23 Oct. 2002 articles in New Scientist, "NASA prepares to boldly go" and "Space station radiation shields 'disappointing'." The first summarizes NASA thinking about placing a space station at the L1 Lagrangian point between Earth and Moon, near the Moon at a location that is gravitationally advantageous but far outside the protection of Earth's magnetosphere. The second article explains why it appears that the risks of radiation exposure on the current International Space Station may be higher than thought, despite special construction and being inside Earth's magnetosphere. Two possible solutions for the future are creating radiation barriers of rock, as proposed above, or using ice/water shields, which is the approach used in another NIAC proposal, for the AstroTel Mars transportation system.
Update #2: Professor Komerath told A/CC in a 28 Oct. message that he has created a new Tailored Force Fields site. It has his team's 24 Oct. presentation to NIAC in PowerPoint/XML or PDF form, additional information about force fields and the author's thinking about how they relate to a space-based economy, and an answer to "OK, so how realistic is any of this? He told A/CC,
[The] people who want to build lunar-based solar power plants, mine metals on the Moon, etc. have come a long way. And your community has systematically observed over a thousand NEOs, many of which require less energy to visit than the Moon. It's time we integrated the advances in all of these [areas] and developed a coherent plan for the next decade. . . I do hope that the NEO community will help me learn more about what orbits, objects and materials are the best ones to go after, as we refine the concept.
Small object "small risk"
A 7 Oct. news release, "Small Asteroid Impacts Less Than Expected," from the Space Science Institute, about simulations run by Allan Harris to determine risks from impacts by small asteroids, resulted in Sky & Telescope's 8 Oct. "Threatening Asteroids: Fewer Hits in our Future?" and Space.com's 9 Oct. "Risk of Small Asteroid Strikes Lowered" articles.
A/CC noted that, for a non-scientific comparison, one can examine the JPL Current Risks page. On 9 Oct. it had no objects listed of the kilometer-plus size that current surveys are tasked with finding, and only five were larger than half a kilometer. Of the objects listed, 35 out of 43 were in the under-200m size range addressed in the above study. In regard to the study's 50-75m "Tunguska size" range, six of the ten on the JPL page on the 9th were LINEAR discoveries, so about 20% of the ~30 LINEAR objects cited in the study were active risk concerns on the 9th, which seems disproportionate within LINEAR's overall discovery stats. Statistical factors at play here include: 1) A higher proportion of smaller objects is expected in the NEO population. Being harder to find, smaller objects should be individually 2) less likely to appear on the risk pages, but, once there, are 3) harder to track and eliminate.
(updated 4 Dec.)
Chris Peterson's Cloudbait Observatory Fireballs page has links to reports of what turned out to have been three southwestern fireballs seen in early October, at 7:22pm MDT 6 Oct. mainly over Colorado and 7:18pm MDT 7 Oct. over New Mexico. About ten minutes after the first sighting on the 7th, according to the latter page, Colorado observers reported a second "much less bright" fireball that Peterson says may get its own separate investigation. The two big fireballs flew in from very different directions, and both are predicted to have had pieces that reached the ground.
Chris Peterson is a high school science teacher and amateur astronomer who collects fireball witness reports on behalf of the Denver Museum of Nature & Science. The museum's team is still working on collecting and analyzing reports from the 6 Sept. 2002 fireball, about which Peterson also has a report and map.
- "Students scan skies for great balls of fire," 9 Oct. Rocky Mtn. News article
- "Another Meteor Spotted Monday Night
," 8 Oct. KMGH-TV Denver article
- "Colorado gets visit from another unearthly visitor," 8 Oct. Rocky Mtn. News article
- "Second meteor sighting in two days," 8 Oct. KUSA-TV Denver article
- "Fireball in sky likely a meteor," 7 Oct. Rocky Mtn. News article
- "Bright Meteor Seen Streaking Across Sky," 7 Oct. KMGH-TV Denver article
When news and advertising converge . . .|
Click to see enlarged.
- "Westerners report green, purple flaming meteor," AP wire on CNN 7 Oct. – about the 6 Oct. event, a "spokesman for the North American Aerospace Defense Command in Colorado Springs [said] 'We don't have a mission to track meteorites, but that's got to be what it is.'"
- For more about Chris Peterson's teaching and astronomy work, see Patrolling for fireballs, and also Astronomy.com's 21 September article about how the Contour Comet Challenge is going on despite the mission failure.
50000 Quaoar (2002 LM60)
50000 Quaoar (2002 LM60) was discovered on 4 June 2002 in images from the Palomar telescope that the JPL NEAT program uses to search for near-Earth objects. Precovery images have been found from that instrument and especially from NEAT's Air Force Hawaiian telescope, with the so far earliest image found on a 17 July 1982 archival plate from Siding Spring in Australia.
- "Major Minor Planet," 8 Oct. Astronomy.com article with locator chart
- "New object puts Pluto back in dock," 8 Oct. Nature article
- "Astronomers discover huge, icy object beyond Pluto," 8 Oct. Orlando Sentinel article (O.S. corrected)
"I think this is spectacular," said Alan Stern. . . "But I would not be surprised if we found objects substantially larger than Pluto the size of Mars or even Earth."
- "New Planet-Shaped Body Found in Our Solar System," 7 Oct. Natl. Geographic article
- "A Cold New World," 7 Oct. Science@NASA article
- "A New Kuiper Belt Kingpin," 7 Oct. Sky & Tel. article
- "Astronomers spot icy world beyond Pluto," 7 Oct. UPI article
- "New Solar System body revealed," 7 Oct. New Scientist article
- "Large world found beyond Pluto," 7 Oct. BBC article
- "Biggest object since Pluto found in solar system," 7 Oct. CNN article
- "Curious Quaoar blurs the line
between planets and mini-worlds," AP wire on MSNBC 7 Oct.
- "Discovery: Largest Solar System Object Since Pluto," 7 Oct. Space.com article
Fact check: Quaoar "is the most distant thing in the solar system photographed by an optical telescope." The STScI news release, without reference to spectrum, says, it "is the farthest object in the solar system ever to be resolved by a telescope." That is, the most distant to be observed as more than a dimensionless point of light.
- Chad Trujillo's Quaoar Precoveries & Quaoar FAQ pages
[A] small white object could reflect the same amount of light as a large dark object. However, a dark object absorbs much more light than a white object, so it will be hotter. By measuring the heat . . . coming from Quaoar and comparing it with the optical reflected light, we know that Quaoar has a diameter of 1250 km.
- "Beyond Pluto: Max-Planck radioastronomers measure the sizes of distant minor planets," 7 Oct. Max-Planck Inst. news release
- "Caltech planetary scientists find largest object in solar system since Pluto's 1930 discovery," 7 Oct. Caltech news release
[The] good news for the serious amateur astronomer is that he or she doesn't necessarily need a space telescope. . . Armed with precise coordinates and a 16-inch telescope fitted with a CCD camera the kind advertised in magazines . . . an amateur should be able to obtain images on successive nights that will show a faint dot of light in slightly different positions.
Fact check: Both the original and "corrected" versions of this news release have some erroneous dates and credits. The original said that "The researchers...soon found images taken in the years 1982, 1996, 2000, and 2001." It should have said 1983, not 1982, and that has been since corrected. The 2002 LM60 precovery from the 1982 Siding Spring plate is credited to Gareth Williams and C.L. Marsden, not Brown and Trujillo. Both the original and "corrected" news release say that "Quaoar apparently was first photographed in 1982 by then-Caltech astronomer Charlie Kowal." It should say, "Quaoar was apparently first photographed in 1982 at Siding Spring in Australia." The plates Kowal gets credit for taking, and from which Brown and Trujillo get credit for precovery, were taken at Mt. Palomar in 1983.
The original errors are still present in 7 Oct. verbatim postings of the news release at SpaceDaily as "Another Candidate For Planet X Found Beyond Pluto," and at Caltech Tech Today as "Caltech Astronomers Discover Quaoar, a Planet-Sized Object in the Solar System." One of the errors (1982 vs. 1983) is also perpetuated in the 12 Oct. Science News article, "Hefty Discovery: Finding a Kuiper belt king."
- "Hubble Spots an Icy World Far Beyond Pluto," 7 Oct. Space Telescope Science Inst. news release [images]
Approximately half the size of Pluto, the icy world 2002 LM60, dubbed "Quaoar" [a local native American creation god] (pronounced kwa-whar) by its discoverers, is the farthest object in the solar system ever to be resolved by a telescope. . . Although smaller than Pluto, Quaoar is greater in volume than all the asteroids combined (though probably only one-third the mass of the asteroid belt, because it's icy rather than rocky). . . Quaoar is about 800 miles (1300 kilometers) in diameter.
- IAU MPEC 2002-T34, released overnight 6-7 Oct.
- "Something Wonderful," by Alan Stern of SwRI on SpaceDaily (6 Oct.?)
[The] Kuiper Belt is the largest single structure in our planetary system. [It] contains more water and more organic material than is present in the entire inner solar system. [Some Kuiper Belt Objects] may soon be revealed to have atmospheres.
1937 UB Hermes recovery?
Announced 4 Oct. in MPEC 2002-T14, 2002 SY50 is an Earth orbit-crosser of low inclination that will be receiving a lot of attention from now into 2003. It was announced with already 114 observations, a high count for a newly discovered asteroid. It was first noticed by LINEAR on 30 September, and there are also LONEOS observations from 18 September. Timothy B. Spahr notes in the MPEC that the orbital elements "bear a striking resemblance to those of 1937 UB," and "both the 1937 and the 2002 observations yield [chaotic] orbits that allow very close approaches to the earth, Venus and Mars."
The long-sought 1937 UB is unusual both for its close approach in 1937, at less than two lunar distances, and for having been noticed. It is also odd among unnumbered asteroids for having a name, Hermes (unofficial). For a history of the discovery and recovery efforts, see Lutz D. Schmadel and Joachim Schubart's page, "Efforts on 1937 UB 'Hermes', a lost Apollo Asteroid" (which predicted 2003 as favorable for recovery). Hermes has been associated with the October Cetids meteor shower (see Kronk), and with HED meteorites (see Wood, et al.), which are also attributed to 4 Vesta and its many splinters, some of which are NEOs.
It is interesting to bring up JPL Orbit Viewers side-by-side for 1937 UB and 2002 SY50 for rough comparison. Any orbit for 1937 UB is highly uncertain, of course, and SY50's orbit determination is a work in progress.
Sky & Telescope's 15 Oct. Astro Alert tells about 2002 SY50, the effort to identify it with the lost 1937 UB Hermes, and a light curve from Campo Catino.
A big NEAT discovery
One of the JPL NEAT program's latest discoveries is big but hardly threatening. EKBO/Plutino 2002 TX300 has a perihelion calculated at 38.012 AU and an inclination of 25.9°. It was announced in MPEC 2002-U17, issued overnight 21-22 Oct., as having been discovered on the 15th. Later on the 22nd, MPEC 2002-U19 reported DANEOPS precoveries going back to 27 August 1954 from plates taken with the same 1.2m Schmidt telescope on Mt. Palomar, as well as in the years 1990, 1991, and 1995. DANEOPS also found TX300 in NEAT images from October last year and this September, and in a 1982 plate from the 1.2m Schmidt telescope at Siding Spring.
NEAT estimates 2002 TX300's diameter at 900 km. (540 miles), making this "the fourth largest known" trans-Neptunian object (TNO). The largest, 2002 LM60 Quaoar, was discovered with the same telescope in July and announced earlier this month.
25 September Siberian fireball – possible impact
(updated 27 July 2003) The Russian tabloid Pravda reported on 3 Oct. that, "Residents of the town of Bodaibo in the Irkutsk region witnessed the fall . . . of a very large luminous body, which looked like a huge stone," and, although it fell "very far from any settlements, . . . locals felt a strong shock, which could be comparable to an earthquake." A date was not given in the report.
No tremor was mentioned in the late Friday, 4 Oct. article from the Russian news service, Interfax, headlined "Russian scientists unable to visit presumed meteorite site." It quotes a Russian academic official as saying there was "no doubt" that a meteorite "fell into the taiga on Thursday." The report doesn't say whether that was Thursday the previous day (the 3rd) or Thursday the previous week (the 26th). "He cited hunters as saying the supposed meteorite had left a large crater surrounded by burned forest." This brief article ends with, "scientists were fearing the meteorite was a lump of ice that would melt away before an expedition came."
Alan Boyle's "Cosmic Log" of 4 Oct. on MSNBC reported that an Anchorage, Alaska TV station had aired video of a fireball seen there early on 2 Oct., and speculated that it might have been part of the same event. However, unless there was a second Siberian fireball, the Siberian event actually took place during the night of 24-25 Sept.
Peter Brown has posted on his page of DoD satellite fireball observations a news release giving details of "a bolide near Bodiabo [sic] in Siberia at 16:48:56 UTC on 24 Sept." Duncan Steel's analysis of that report in the 14 Oct. edition of the Cambridge Conference Correspondence is that this would have been an atmospheric event of around 0.2 kilotons and not a significant ground impact. That seems to be affirmed in the same edition by Russian scientist Mikhail Nazarov, whose report of a 25 Sept. fireball at 1:50am local time is that seismic stations in the area did not register an event, with the possible exception of the station at Bodaibo.
The Russian news agency Novosti said in a brief 21 Oct. update that there is seismological data from the 25 Sept. event, and that it has helped better determine the most likely location of any object remnants, which an expedition is preparing to go look for.
According to . . . data obtained by Irkutsk seismologists and an American satellite . . . the meteorite fell on September 25th about 30km from the Mama village, not in the Bodai district as was previously believed.
Novosti next reported on 28 Oct. that Sergey Yazev, director of the observatory at Irkutsk State University, had reported that there was indeed a 25 Sept. meteor impact, found 37 km. (23 miles) from the settlement of Mama in the northern Irkutsk region. The indication was damaged trees, and any search for fragments will have to await Spring, since the area is now covered in deep snow.
The story picked up in the Spring with Novosti reports on 9 March of a scientific team preparing to visit the site, and on 6 April of its departure: "six men from three institutes of the Irkutsk Research Center of the Russian Academy of Sciences' Siberian Division" have left on an expedition to where they believe they can collect dust, if not pieces.
Interfax reported June 6th that an expedition had "found an area of about 100 square kilometers covered with burnt trees and pieces of the meteorite" near Mama in the Irkutsk region from last September's fireball. RIA Novosti also had a 6 June report.
CNN posted a brief AP wire story 20 June 2003, also carried by many other mainstream news sites, about Russian scientists studying the reportedly devastated impact area, who said on Rossiya TV that this is "a colossal historic event" involving maybe two meteors exploding with "the force of a medium atomic bomb." The credibility of such reports is reviewed in the Cambridge Conference Correspondence for July 10th.
RIA Novosti had a July 25th report that what is now being called the "Vitim" meteorite "was probably a comet," while Gateway to Russia had an item on July 27th that "Russian scientists claim Vitim meteorite to be ice boulder," and News24.com of South Africa had a July 28th item, "Giant meteorite wrecked forest": "Over an area of 100 square kilometres trees were smashed in a pattern characteristic of very powerful blast effects," expedition leader Vadim Chernobrov told a news conference.
Headlines (newest first)
- "Giant meteorite wrecked forest," 28 July article at News24.com
- "Russian scientists claim Vitim meteorite to be ice boulder," 27 July item at Gateway to Russia
- See Cambridge Conference Correspondence for 10 July 2003 (posted July 14th) for an interesting review of available info
- "Meteorite crash site located in Siberia," AP story on CNN 20 June 2003
- "DoD Satellite Tracked Siberian Fireball that Might have Hit Earth," 14 Oct. Space.com article (see next CCC item for details)
- Cambridge Conf. Corresp. of 14 Oct., has several related items
- "Cash plea for Russian meteor chasers," 8 Oct. BBC
- Alan Boyle's "Cosmic Log" of 4 Oct. on MSNBC
- "Russian scientists unable to visit presumed meteorite site," 4 Oct. Interfax article
- "Asteroid 'hit northern Russia'," 4 Oct. Ananova article
- "Shooting star crashes in Siberia," 4 Oct. Independent of South Africa article
- "Large Meteorite Falls on the Irkutsk Region," 3 Oct. Pravda article
Comet 19P/Borrelly surface description
- "Comet's Features Look a Lot Like Some on Earth," 21 Oct. Space.com article, includes composite image & a great map
- "Comets: Complex Worlds," 9 Oct. U.Tenn. news release from Daniel Britt
What we see on Borrelly are a series of flat-topped, steep-sided hills. . . We call these mesas and they are probably formed much like the terrestrial mesas. . . What we do not see . . . are any impact craters. [Borrelly] seems to be broken into two pieces [that] appear to 'chaff' [sic] against each other, raising what look like compressional ridges.
2002 AA29's co-orbit with Earth
(updated 3 Feb. 2002) There are several small asteroids known or suspected to travel in orbits synchronized in a 1:1 mean resonance with Earth, such that they sometimes are in Earth's own orbit, but never in the same place at the same time as the Earth. These orbits, which tightly loop within a larger horseshoe pattern when illustrated relative to Earth's path, are described as having. The most famous of these is the first described to have such a bizarre orbit, 3753 Cruithne. That 2002 AA29 is another such "co-orbital" object made headlines in October 2002, and again in January 2003.
Headlines (newest first)
Two of the paper's authors, Paul Wiegert and Kimmo Innanen, are showing that the large outer planets could have stable populations of similarly co-orbital objects, especially Uranus and Neptune. See their Quasi-satellites page.
- "If the Horseshoe Fits...," Astronomy.com 1 Dec. 2002 article
- "Asteroid follows Earth around orbit," 22 Oct. New Scientist article
- "Earth's New Travelling Companion: Quasi-Satellite Discovered, 21 Oct. Space.com article, repeated on MSNBC 21 Oct. as "Quasi-satellite of Earth discovered"
- "Earth's little brother found," 21 Oct. BBC article
But astronomers classify 2002 AA29 as the first real co-orbital body found associated with the Earth because it more completely shares the Earth's path around the Sun [than does earlier discovery] 3753 Cruithne.
- Oct. 2002 Meteoritics & Planetary Sciences article (abstract) by Martin Connors with Chodas, Mikkola, Wiegert, Veillet, and Innanen. The article preprint (1.33Mb PDF) is available from Paul Wiegert's Earth coorbital asteroid 2002 AA29 page, which itself has a lot of information with images and animations.
MPC workload milestone
With Minor Planet Electronic Circular 2002-U40 of 28 Oct., the IAU Minor Planet Center (MPC) issued its 1304th MPEC of 2002, which is equal to the total number of MPECs issued last year, while a sixth of 2002 is yet ahead. By A/CC's count, this was the 6350th MPEC issued since these electronic circulars were begun on 19 Sept. 1993. During the first three full years, no more than 207 MPECs were issued per year. That was before the advent of almost-daily Daily Orbit Update MPECs (the first was issued on 16 December 1997), and, of course, was before the automated NEO surveys kicked into high gear.
The MPC is colocated with the Central Bureau for Astronomical Telegrams (CBAT), which just two days earlier issued its 8000th International Astronomical Union Circular. IAUC numbering is cumulative rather than annual, going back long before the Internet and the Minor Planet Center, but some older IAUCs are available online going back to IAUC 1 of 22 Oct. 1922, which was issued from Copenhagen Observatory in French about a new comet discovery.
The Minor Planet Center is on overload with today's rapidly growing number of discoveries, and is badly in need of better institutional funding. Contributions from concerned individuals is good way everyone can help advance the science of minor objects (learn more).
SWAT spots a dozen TNOs
Daisuke Kinoshita and Kyoko Muroi of the Solar System WAtching Team (SWAT) put Japan's 8.2m Subaru optical/infrared telescope to work discovering twelve trans-Neptunian objects and a Centaur on 6 Oct. They followed up on the 7th, taking a couple dozen positions per night for each object. The announcements were made in MPECs 2002-U37, 2002-U38, and 2002-U39 of 28 Oct. Most of these objects have semimajor axes initially calculated in the range of 43.21 to 45.78 AU, a couple at just over 39 AU, and one at 16.1 AU. Some do not yet have their orbital eccentricity determined.
Micrometeorite classroom project
A University of Rhode Island (URI) news release of 10 Oct. (picked up by space news sites 28 Oct.), "URI geologist tracking 'cosmic dust' with help of local teachers," says that URI professor Daniel Murray and retired teacher/education innovator Jim Sammons "hope to recruit hundreds of teachers around the country" to work with students to collect meteorite and other atmospheric dust as an "opportunity to conduct real science in the classroom." This is something that Rhode Islanders have been doing for more than a year now following two workshops on this activity. Murray, who chairs the URI Geosciences department, is quoted as saying, "every night you're likely to find [a meteorite particle] on the hood of your car and on every other surface the size of the hood of your car."
A 30 Oct. Geophysical Research Letters news release posted on SpaceRef.com and EurekAlert reported that a Southwest Research Institute-led team has not only identified the mysterious source of "anomalous cosmic rays," but also found a new medium by which to perform remote sensing of the Edgeworth-Kuiper Belt. (The Institute later posted its own news release, dated 30 Oct.) The reported source is dust from collisions between belt objects. As these particles drift sunward, ions are "sputtered off" by the solar wind, which then accelerates the ions, but they are slower and of a different composition than cosmic rays of the interstellar variety. Sky & Telescope has a 1 November report, as does Space.com on 5 November ("Kuiper Belt Objects . . . slam together and generate dust that drifts inward, polluting the entire solar system").
Risk concerns removed during October 2002
Potentially hazardous asteroids removed from the NEODyS and/or JPL risk pages during October 2002 include: 2002 QW47, 2002 SQ41, 2002 TB9,2002 TB70, 2002 TA67, 2002 TC9, 2002 TD66, 2002 TX55, 2002 TW55, 2002 TZ59 & the on- and off-again 2002 RW25
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