Dec. 2002 Asteroid/Comet News

5 December 2002

2002 TB9, which was on the JPL and NEODyS risk pages during 4-8 Oct. 2002, was updated on 5 Dec. in MPEC 2002-X32 based on precovery observations found by DANEOPS on Mt. Palomar plates from 16-17 May 1991.

The Ondrejov NEO Photometric Program continues to update a very interesting page on 2002 TD60, "a tumbling monolith." Based on observations from several observatories during Nov. and Dec. 2002, TD60 is found to be large and elongated enough, and spinning fast enough, to make it "the second largest coherent asteroid known" after 2001 OE84. See also IAUC 8017.

MPEC 2002-X50 of 8 Dec. announced the recovery of 2001 PM9 from observations on the 7th and 8th with the Spacewatch 1.8m telescope. It hadn't been seen since 10 Sept. 2001, when it left behind an uproar big enough to merit a 5 Sept. 2001 special issue of Tumbling Stone, which included an article subtitled "the worst holiday of my life," by Andrea Milani of NEODyS.
      Following PM9's discovery with NEAT's Palomar telescope on 11 Aug. 2001 (MPEC 2001-P36), alarms were briefly raised over very preliminary possible impact solutions in the near term, from 2003 to 2007, by an object estimated at about a kilometer in size (600 to 1,300 meters/yards). In less than two weeks, however, follow-up observations let the "all clear" be sounded.
      For more about 2001 PM9, see Space.com's 23 Aug. 2001 report, "Asteroid No Threat, Despite Rumors of Earth Impact," the European Spaceguard observing campaign 4 Sept. 2001 report, and JPL's Orbit Viewer. The uproar over 2001 PM9 and how to better handle "virtual impactor" reporting was discussed at length in the 24 and 31 Aug. 2001 editions of Cambridge Conference Correspondence.

The NEAR mission reported on 12 Dec. [that page's "2001 Feb 23" date is erroneous–Ed.] that a 12-hour attempt on the 10th wasn't successful in waking up and communicating with the NEAR-Shoemaker spacecraft on the surface of 433 Eros. The problem isn't known, but the spacecraft has been in deep cold for almost two years, and the team doesn't plan to try again.

Space.com reported 14 Dec. about about looking in Clementine images for a candidate crater from what may have been a witnessed and photographed 1953 lunar impact, an idea that led to a January debate.

JPL's 18 Dec. news release, "Creepy Crawlers May Unravel Web of Planetary Mysteries," tells of work by JPL's Mobility Systems Concept Development Section toward miniature robots that can work together in self-reconfigurable networks to collectively explore the surface of a planet, moon, asteroid, or comet.

13-14 December Geminid meteor shower

The Geminids are associated with 3200 Phaethon, which may be an inactive or extinct comet nucleus.

• SpaceWeather.com's 2002 Geminids Meteor Gallery
• "Meteors from the Twilight Zone," 9 Dec. Science@NASA article
• "Geminid Meteor Shower Underway, Peaks Saturday Morning," 12 Dec. Space.com article, updated from a 6 Dec. article
• Gary Kronk's Geminid History page

(updated 6 Jan.) In IAUC 8034 of 17 Dec., the Minor Planet Center reports that 2001 QC298 has been found to be binary through observation with the Hubble Space Telescope. QC298 is a Cubewano discovered by Lowell Observatory's Deep Ecliptic Survey on 19 Aug. 2001 from Cerro Tololo in Chile, and has been subsequently found in Kitt Peak images from 19 Sept. 2000. For more info on QC298, see MPECs 2001-T40 and 2002-P49, the JPL Orbit Viewer, and Lowell's QC298 page.
      The 12 Dec. 2002 issue (420) of Nature has two items about EKBO binaries. One of these, "Formation of Kuiper-belt binaries by dynamical friction and three-body encounters," by Peter Goldreich, Yoram Lithwick, and Re'em Sari, employs some rough calculations to explore collisionless gravitational interactions to explain the evolution of widely separated binaries. The preprint is available from arxiv.org as a 274Kb PDF.

• "New Theory Accounts for Existence of Binaries in Kuiper Belt," 13 Dec. Caltech news release + animations
• "Asteroid moons pulled in by gravity," 13 Dec. UPI article (original posting 11 Dec.)

A/CC reported on 6 Dec. that the NASA Space Infrared Telescope Facility (SIRTF) launch has been moved again, from 9 Jan. to "no earlier than April 15, 2003." Once launched, it will require about two months to reach operating temperature and another month for testing, and then will perform a survey before being turned over to observing projects. As noted on the SIRTF Planets science page, SIRTF was planned to work in conjunction with Contour next November to study 2P/Encke as it passes Earth on the way to perihelion. With the loss of Contour, SIRTF's role would now seem to be even more important, if it can be on station and operational in time.
      This story resumed in March with SIRT's arrival at Kennedy Space Center and preparations for the April launch, but, on 18 April, it was decided to "de-stack" the SIRTF spacecraft from its launcher on its launch pad and reschedule for an August 2003 launch.
      For more information about SIRTF, visit the mission site and read Aviation Week & Space Technology's 4 Nov. mission preview, "Final 'Great Observatory' To Probe the Universe." Also see SIRTF scientist William Reach's page about 2P/Encke observations made with the old Infrared Space Observatory (ISO).

A NASA Johnson Space Center 11 Dec. news release reports that researchers working on samples from the Tagish Lake meteorites have "found numerous hollow, bubble-like hydrocarbon globules in the meteorite [that] 'would have been ready-made homes for early life forms'" when such materials landed on Earth and maybe elsewhere in the Solar System. This report references work at NASA Ames Research Center that predicted such globules, or vesicles, as told about in an Ames news release of 26 Jan. 2001 and the Vesicles from Space page. Related Ames work is reported in a news release of 18 Feb. 1999, and also see another from 19 Dec. 2001.

• "Primitive Housing: Potential Homes for Earth's First Life Found in Space Rock," 13 Dec. 2002 Space.com article
• "Meteorite 'ready-made home' for life," 25 Dec. 2002 CNN article
• "A Meteor's Protective Bubbles?" 2 March 2003 Astrobiology Magazine article

A joint news release of 18 Dec. 2002 from the Chandra X-ray Observatory's Harvard-Smithsonian and NASA/Marshall operation centers tells about observation of a young star cluster unexpectedly enveloped by extremely high-energy particles that "could cause dramatic changes in the chemistry of the disks that will eventually form planets around stars in the cluster."

“ If our solar system was immersed for a time in a sea of energetic particles, this could explain the rare nuclides present in meteorites found on the Earth today . . . (Aluminum 26 being the most well known). ”

Potentially hazardous asteroids removed from the NEODyS and/or JPL risk pages during December 2002 include: 2002 VY91, 2002 XA, 2002 XO14, and 2002 XR14. See A/CC News for details.