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

Today's issue status: done

• News briefs – surveillance, small object news & Sedna on the mind
  panel 2 – Queensland event & radar news
• Risk monitoring
  – NEODyS has posted 2004 FY31

Cover: Sixty 8-second exposures stacked on the fast motion of 2004 FK5 makes background stars appear as strings of beads in this imagery by Peter Birtwhistle from the night of March 24th, a day after FK5 came within 5.7 lunar distances of Earth. See his 2004 FK5 page to learn about the difficult pursuit of this object during the confirmation process, and see last week's small objects report for more about 2004 FK5.

Surveillance:  The Flushing (New York) Times Ledger reports today that Congressman Anthony Weiner has introduced a bill to "channel $4 million into NASA coffers next year to underwrite the cost of sharing four . . . 5-foot-11-inch Department of Defense telescopes, which are under development." This is "to help track and catalog dangerous, near-Earth asteroids" such as 2004 FH, which is described as 328-ft. wide and "could have created a crater the size of Central Park." As Marco Langbroek has reported here about 2004 FH's size and meteoric potential, the best guesstimate is around 55 ft. wide, and the outcome, if 2004 FH had entered Earth's atmosphere, is estimated as far less dire, and quite likely just a very impressive fireball. The article also has this "factoid,"

“ And by 2008, NASA should be able to spot 90 percent of near-Earth space bodies larger than one meter across. But that leaves a lot of smaller — but no less deadly — asteroids out there. ”

which appears to be related, not to April Fools Day, but to American familiarity with the metric system.

Small object news:  MPEC 2004-G01 today announces 2004 FM32 as discovered Tuesday morning and confirmed the next morning by LINEAR in New Mexico, and also confirmed this morning by Powell Observatory in Kansas and Table Mountain Observatory in southern California. The MPC Ephemeris Service (MPES) shows it to have been at about 1.8 lunar distances from Earth overnight 25-26 March UT. At absolute magnitude (brightness) H=27.2, the best rough estimate at its diameter is 12 meters/yards.

Sedna on the mind:  In a Royal Astronomical Society news release from yesterday, "Life Beneath the Ice in the Outer Solar System?" mostly about Jupiter's moon, Europa, David Rothery is quoted as saying, "Episodes of tidal heating in some of the Solar System's other icy bodies could equally well have given rise to life, even in such remote bodies as the newly discovered, remote planetoid Sedna [2003 VB12] if, as has been suggested, it has a satellite with which to interact tidally." And Astronomy.com has an article from yesterday, "Sedna: comet or KBO?"

more news briefs >>

<< continued from panel 1

Queensland event:  On day two of puzzling over what happened Wednesday evening, there are these reports dated April 2nd in Australia:

• Brisbane Courier-Mail, "Great ball of fire! No April Fool's joke"
• Townsville Bulletin, "Meteor fires up North"

  “ The second [aerial] sighting was by a chartered flight. . .  Leon Tengbom, a passenger [said he] was sure the fireball hit the ground, as the passengers on the flight watched a stationary red glow on the dark ground for about 10 minutes after impact. ”

See yesterday for the first reports.

Radar news:  JPL's Lance Benner recently reminded observers on the Minor Planet Mailing List (MPML) about three NEOs that have been on the Arecibo and/or Goldstone schedules for awhile as April-May radar targets, noting that "Astrometry would be very helpful for 2001 US16 and 2003 YT1 and physical observations of all three objects are desirable."

The 2003 YT1 planning page notes "Its absolute magnitude of 16.2 suggests that it is within a factor of two of about 1.8 kilometers in diameter [and] is

probably one of the larger near-Earth asteroids that we have observed in the last few years at Goldstone." From mid-December discovery it was observed steadily until January 10th, but has been reported only three times since then, and last on March 22nd.

2001 US16's planning page notes that it is a PHO perhaps 250 meters in diameter, gives photometric results new today from Petr Pravec (rotation and spin state), and says "Among all near-Earth asteroids, this object has one of the lowest delta-V values for a spacecraft rendezvous, making it a likely target for a future mission." It was picked up with the Spacewatch 1.8m telescope in Arizona on January 29th for the first time since November 2001, and has been closely followed since then by many observatories.

The other NEA, 1999 DJ4, is also a PHO and is between the other two in size, estimated at roughly 700 meters wide. It was recovered by the JATE Asteroid Survey in Hungary on December 27th and observers have stayed on top of it since. It hadn't been seen since December 2000, when it was observed only twice after having been out of view since 1 September 1999.

Risk monitoring 1 April

NEODyS today posted 2004 FY31, which JPL posted early today (before midnight in Pasadena). It was announced yesterday in MPEC 2004-F98 as discovered earlier in the day by LONEOS in Arizona and confirmed soon by Table Mountain, Powell, and Sabino Canyon observatories in southern California, Kansas, and Arizona, and last night by Consell Observatory in Spain.

At last check, at 0200 UTC Tuesday (9pm EST Monday), the Minor Planet Center hadn't posted a Daily Orbit Update MPEC for today or an explanation, and the risk monitors haven't updated their risk assessments. The MPC Last Observation page in the last 24 hours has shown new observations of 2004 FU4 with the Spacewatch 1.8m telescope in Arizona yesterday morning and Tenagra II Observatory in Arizona this morning, of 2004 FE31 by Desert Moon Observatory in New Mexico yesterday morning, and of 2004 FN18 by Tenagra II this morning, and there may be other data in the pipeline.