July 2002 Asteroid/Comet News

1 July 2002

The Smithsonian Astrophysical Observatory, of the Harvard-Smithsonian Center for Astrophysics, announced July 1st the seven recipients of the Edgar Wilson Award for the year ending June 2002, which involves plaques and checks in addition to some additional fame for Mssrs. Ikeya, Murakami, Petriew, Snyder, Utsunomiya, Yeung, and Zhang of Canada, China, Japan (3), and the U.S. (2). Five of their six comets were visual discoveries, using binoculars or small telescopes — the most since 1994 and quite an achievement in the age of automated NEO search programs. And one of these, Ikeya-Zhang, is the recovery of a comet seen in 1661, now the comet with the longest orbital period (341 years) that has been actually observed.

11 July 2002

The 11 July issue of Nature has an article about new information on nanodiamond distribution in micrometeorites and what it appears to mean for the formation of the Solar System. See the Lawrence Livermore National Lab 11 July news release and reports at Space.com 10 July, Astronomy.com 16 July, and Sky & Telescope 19 July 2002.

17 July 2002

A NASA headquarters news release (corrected 24 July from the 17 July original text and JPL's illustrated version) tells about a gravity assist-plus approach to designing planetary space missions, as refined and put into software by JPL's Martin Lo. The idea isn't just to pick up speed and course changes by looping around planets and moons, but to also pass through and use the planets' and moons' Lagrange points where the gravity influences of multiple bodies are canceled out. This is putting chaos theory to an orderly use, and Lo's new LTool software reportedly makes calculating these paths relatively quick and easy as compared with old gravity-assist trajectory planning.
      LTool was used on the Genesis mission launched last August. The mission site has posted a June interview with Martin Lo, in which he says, The halo orbits at [Earth's] L1 and L2 [points] are actually "portals" to a network of dynamical tunnels that connects the entire Solar System. By jumping into the "hole" in the halo orbit, you enter this vast and ancient labyrinth of tunnels and passageways that connects the Kuiper Belt beyond Pluto to all of the planets, all the way to the Sun.
      The down side is that minor objects can follow such paths toward the Earth, just as Genesis itself is on a complex Earth-collision path in order to return particle samples from the solar wind.
      CNN has a 19 July report.

18 July 2002

An 18 July Associated Press item (see CNN and Space.com) based on an Interfax Military report of 18 July tells about Russia coming online with a new "space control" system at the Okno facility near Dushanbe, Tajikistan. It apparently has optical tracking capabilities somewhat akin to the U.S. Air Force facilities of which MIT's LINEAR program is an outgrowth (GEODSS), and with which JPL's NEAT Hawaiin program is associated (MSSS). Asteroid-observing capabilities aren't mentioned, however.

19 July 2002

In the 19 July updating of Discovery Circumstances by the IAU Minor Planet Center, there were 177 new asteroid namings, largely for LINEAR and LONEOS discoveries. The highest-numbered asteroid now publicly named is 42191 Thurmann (2001 CJ37). Other new namings include 6962 Summerscience (1990 OT), 13358 Revelle (1998 TA34), 13752 Grantstokes (1998 SF58, a LONEOS discovery), 16157 Toastmasters (2000 AS50), 25399 Vonnegut (1999 VN20), and 38083 Rhadamanthus (1999 HX11). There was also a name change, to Gunnarsson from Undset for 10265 1978 RY6, and a name correction: 6533 Giuseppina instead of Guiseppina.
      No new numberings were issued for asteroids, but comet Ikeya-Zhang C/2002 C1 was numbered 153P.

21 July 2002

A meteor exploded over Boqate Ha Sofonia, Lesotho in Africa on 21 July. See the BBC's 22 April 2003 article, "Meteor caused Lesotho 'poltergeist'."

23 July 2002

Lockheed-Martin put a news release out 23 July about its participation in the coming ESA Rosetta comet-lander mission with an ion spectrometer, and also tells a little about Carl A. Wirtanen of Lick Observatory, who discovered the mission's destination, 46P/Wirtanen, in 1948.

27 July 2002

A bolide over Italy on 27 July has been reported.

30 July 2002

The Planetary Society on 30 July announced its 2002 Shoemaker Near Earth Object Grants. Recipients include $8,140 to John Broughton of Reedy Creek, Queensland, Australia for the purchase of an Apogee AP6Ep CCD camera to be used on a new computer-controlled 0.46-m telescope [which] will immediately be put to work making follow-up position reports on fast moving NEOs and NEOs that cannot be seen by northern hemisphere observers.

The breakup of comet 57P/du Toit-Neujmin-Delporte

NEAT's 1.2m Palomar telescope on 12 July detected a companion to comet 57P/du Toit-Neujmin-Delporte. On 20 July, Yan Fernandez et al. reported 18 additional fragments, shown in a beautiful mosaic of images taken with the University of Hawaii 2.2m telescope (UH/IfA 24 July news release). He describes "a zoo of fragments strung out in a line extending almost 30 arcmin [the Moon's apparent width] away from the comet itself." The Arkansas Sky and Klenot observatories also have posted images, as has Campo Catino with this JPEG, and Michael Jaeger. See IAUCs 7934, 7935, 7936, 7937, and especially 7946 and 7957 with analyses of the breakup history.
      This breakup got widespread coverage, as might be expected with a spectacular visual, such as, for example, Astronomy.com 23 July, Sky & Telescope 24 July, CNN 25 July, and BBC 26 July. In comparing this breakup with those of C/Shoemaker-Levy 9 (1993e) and C/LINEAR (1999 S4), S&T says, "57/P's pieces will disappear more slowly [allowing scientists to] gain a better understanding of the structure and fragility of all comets."

Planetary defense advocates cited 2002 MN and other recent close calls and fireballs in two forums that were reported in Scientific American 8 July, Space.com 10 July, Astronomy.com 12 July, Sky & Telescope12 July, Spaceflight Now 12 July, and BBC 15 July. Also raised is the spectre of a meteor explosion being mistaken in these tense times for a first strike and setting off a nuclear conflagration. For more about that, see Space.com's 6 June report, and more below, especially about infrasound detection.
      The 12 July edition of Cambridge Conference Correspondence has reports from David Morrison and Brian Marsden about the 10 July meeting on Capitol Hill. On 16 July SpaceRef.com posted a statement of personal opinion about the meeting and the issues by USAF Gen. Simon P. Worden of the U.S. Space Command, followed with a critique by David Morrison. Worden details the military aspects of impact hazards, and, in an aside, mentions the possibility of capturing an NEO into an orbit around Earth, such as perhaps 2002 AA29.
      August update: Space.com reported 5 August that a $92,000 study, "Natural Impact Warning Clearinghouse Concept of Operations," was begun last Fall and delivered to the U.S. Space Command in June by Science Applications International Corp. (SAIC). Timothy K. Roberts is named as leader of the study, and is quoted as saying, "What is missing is a way to take technical information and put it into terms that decision makers can understand and use." And he notes, "The U.S. military ... snares loads of useful fireball information [that] never gets to command and control nodes."
      Sept. update: See also coverage of the 3-6 Sept. NOAO/NASA hazards mitigation workshop.
      This is good place to mention that Peter Brown at the University of Western Ontario has an archive of almost two dozen U.S. DoD and Air Force news releases from 1994 to 2001 about military satellite-detected meteor events.

More objects found = bigger load on MPC

A Spaceflight Now 12 July article about planetary defense brings up a crucial point that has not gotten enough attention or response: Brian Marsden, director of the Minor Planet Center [MPC] ... estimates that there are about one million NEOs 50 meters across or larger; only 2000 NEOs of any size have been discovered. However, the Minor Planet Center has only 2.5 full-time employees ... who work 16-hour days seven days a week just to keep up with the current rate of asteroid and comet discoveries. For explanation of the Center's financial situation, see the distress calls Marsden sent out in MPECs 2001-W73 and 2002-A03 of last November and January.
      Increased and new institutional funding is what's needed, but individuals can help, too. In his January editorial, Marsden wrote, While it seems unlikely that [donations] could be sufficiently extensive to fund fully even one staff member, all ... are very much appreciated. Instructions on how to contribute (tax deductible in the U.S.) are given in MPEC 2002-C06, and donations are publicly acknowledged in the Minor Planet Electronic Circulars.

Meteor or missile?

Over Dnipropetrovsk in the Ukraine on the night of July 4th, an Israeli El-Al pilot reported what looked to him like a mid-air missile explosion at some distance from his aircraft. A Russian Urals Airline pilot and one other pilot also were reported to have seen the explosion. Benny Peiser wrapped this story up in his Cambridge Conference Correspondence 8 July edition. See also CNN 6 July and BBC 5 July and 6 July reports.
      Two other 2002 European fireball incidents bracket the Ukraine incident. One occurred over Italy 27 July, the other happened 6 June over the Mediterranean, observed by U.S. military satellites as explained by USAF Gen. Simon P. Worden of the U.S. Space Command in a SpaceRef.com 16 July posting. See also 12 July reports at Astronomy.com and Spaceflight Now.

Infrasound detection of large meteor events

Nature has a 17 July article about how atmospheric meteor explosions can be distinguished from nuclear explosions using the infrasound network being put together as a part of the worldwide monitoring system underlying the Comprehensive Test Ban Treaty (CTBT). The article is based on a paper, "Multi-station infrasonic observations of two large bolides," by U.S. infrasound researchers in the 9 July edition of Geophysical Research Letters.
      Infrasound stations in the U.S. monitoring for nuclear explosions are operated by the DOE National Nuclear Security Administration [NMR&E|info], led by Los Alamos National Lab (LANL). News releases 22 May 2001 from LANL and 22 Aug. 2001 from the UC San Diego Scripps Institution of Oceanography tell how infrasound picked up large explosions over the Pacific Ocean west of Mexico on 25 Aug. 2000 and 23 April 2001, confirmed by U.S. military satellites. The two objects were respectively about two and three meters/yards in diameter, yielding two to three and six to eight kilotons of energy high in the atmosphere. See reports by Space.com 24 May and BBC 23 Sept. 2001.
      The Deelen Infrasound Array in the Netherlands (not part of the CTBT network), helped analyze the 6 April 2002 Bavarian bolide, and was in the news earlier about how it picked up a 1.5 kiloton explosion over northern Germany on 8 Nov. 1999 at an altitude of 15-20 km (above 10 miles). See 5 Jan. Nature and 19 Jan. BBC 2001 reports based on a scientific paper by Laslo Evers and Hein Haak published in Geophysical Research Letters of 1 Jan. 2001. You can read that paper as a 1.5Mb PDF available from the lead author's home page. Evers also has a detailed report on a 27 Oct. 2001 bolide infrasound event over the northern end of the English Channel.
      For a number of earlier ultrasound events going back to the 1960s, see a 21 April 1998 Newsday article on the LANL site about the new and earlier infrasound detection systems. It also talks about the half-kiloton explosion almost above El Paso, Texas on 9 Oct. 1997 (see a CNN 10 Oct. 1997 report and Meteorite! map – that blue is Mexico, not the ocean). This came almost exactly a year after 3-4 Oct. 1996, when two meteor events, or possibly the same meteor event (a skip and an entry?), happened north of El Paso and, 104 minutes later, on a line to the west near Bakersfield, Calif. Infrasound monitors picked up more than 60 objects, and researchers want to find meteorites that can be connected with infrasound events, as Sandia National Lab announced on 3 Oct. 1997 with a reward offer. See 14-15 Oct. 1996 AP stories archived in shorter and longer versions at NASA/Ames and Florida Today.

• Rate estimate lowered for atmospheric events (Nov. 2002)

• News 4 June 2003 with a link to a PDF scientific report
• An Associated Press wire story about using infrasound for the Shuttle Columbia investigation appeared on Space.com 16 Feb. & CNN 17 Feb. 2003
• Southern Methodist Univ. Geology Dept. Shuttle Columbia infrasound event page

• "Meteor Trackers Called in to Predict Trajectory of Columbia Debris," 18 Feb. Space.com article
• Shuttle meteor risk assessment