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

Today's issue status: done

• Small objects – report for 29 March-4 April
  Observation summary
• News briefs – Rosetta status & meteor news
• Risk monitoring

Cover: Two of the fast-moving small objects caught by Peter Birtwhistle at Great Shefford Observatory in England the week before last, 2004 FA5 at right and 2004 FN8, the smallest object observed for two weeks (see below). Stacking several dozen frames on object motion causes stars to appear as strings of beads.

Small objects
Discovery & follow-up 29 March – 4 April

This past week, as the Moon brightened, six discoveries of small objects were announced. These asteroids have absolute magnitude (brightness) H calculated at greater than 22.0, roughly estimated at 135 meters/yards wide or less. This compares with seven discovery announcements the previous week, and 13 the week before that. Four of this week's were discovered by LINEAR in New Mexico. One, 2004 FH29, was found with the Siding Spring Survey 0.5m Uppsala Schmidt telescope in Australia, which may have been this program's first discovery with that telescope [it was]. And the other, 2004 FC18, was discovered by FMO Project online volunteer Michael C. Begam while reviewing images from the Spacewatch 0.9m telescope in Arizona (see A/CC's report). Another nine small asteroids were tracked, and observations of four more were reported from the previous week. Two of these four, 1998 XN17 and 2002 FT6, were one-night recoveries by Tim Spahr working with the Whipple Observatory 1.2m telescope in Arizona.

Twenty-three observatories (see below) participated in this work, including the USAF Academy Observatory, and several carried much of the load.

For close flybys by small objects last week, the Sormano Observatory SAEL has just one within ten lunar distances (LD), 2004 FG29 at 0.0155 AU (a bit over 6 LD). And this week the only one predicted happens today, 2004 FH29 at 0.020 AU (7.8 LD).

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Notes: Diameters in the following observation summary table are rough best estimates from a standard but very inexact H-to-size formula using H (absolute magnitude) from the JPL NEO Orbital Elements page, source also for Earth MOID (minimum orbital intersection). Other planetary MOIDs are from Lowell Observatory. Current Minor Planet Center H is also given, along with the original H from each object's discovery MPEC. Priorities and visibilities are from the European Spaceguard Central Node (SCN). NEO orbital elements, H values, and MOIDs are from today, Monday the 5th.

Rosetta status:  The Rosetta mission has posted its sixth status report, dated April 3rd, "Ongoing Commissioing Activities," when the spacecraft was about 27.5 lunar distances from Earth. The NASA/JPL Microwave Instrument for the Rosetta Orbiter (MIRO) was activated and practiced a "a very complex pointing profile resulting in a triple-spiral scanning of the planet Venus." JPL has a MIRO site for this far-infrared sub/millimeter instrument, but with outdated info about which comet and asteroids will be visited.

Meteor news:  The Australian Townsville Bulletin reports tomorrow that "James Cook University astronomy centre director Associate Professor Graeme White said eye witness accounts put one impact site about 60 nautical miles north-northeast of Mount Isa" and is "Keen to hear from anyone who may be able to fly by the area." This continues a news thread from April 2nd ("Meteor news").

The Georgia Savannah Morning News has an article today telling about "Bulloch County farmer holding out for big bucks for not-so-big rock," having refused an offer of $25,000 for the meteorite (photo) found while bean picking. See also A/CC's brief report about the meteorite find.

Risk monitoring 5 April

The Monday Daily Orbit Update MPEC (DOU) carries no observations of objects with impact solutions. The Sunday DOU had observation of 2004 FE31 from the 2.5m Isaac Newton Telescope at La Palma in the Canary Islands early on the 3rd. Yesterday NEODyS cut its impact solution count and slightly lowered its overall risk ratings for this object, while JPL added many solutions and raised its ratings for 2004 FE31 over a period extending 23 years beyond the NEODyS time horizon.