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

Today's issue status: done, updated

• News briefs – aurora alert
• Risk monitoring – NEODyS & JPL have removed 2004 RJ9 & NEODyS has posted 2004 RU109 + update on 2004 RJ9 observation

Cover: Today 2004 RU109 came slightly inside the Earth-Moon system, coming to 0.957 lunar distance (LD) from Earth at 1536 UT (11:36am EDT) according to Pasquale Tricarico, and will pass 0.83 LD from the Moon tonight at 0010 UT (8:10pm EDT). Among those helping confirm the discovery of this object, which is estimated at 10 to 20 meters/yards wide, was Robert Hutsebaut. His composite image at left from yesterday morning consists of six 10-second frames (stacked for motion of 24.55"/min. toward 269.1°, to the right in this image, westward) made with a Rent-A-Scope 0.25m telescope at New Mexico Skies, run from his home in Belgium. See a report yesterday for more about 2004 RU109, and check its impact risk ratings below.

Aurora alert:  SpaceWeather.com earlier today reported that the Sun has thrown a coronal mass ejection toward Earth that “could spark a strong geomagnetic storm when it arrives on Sept. 14th. Sky watchers everywhere should be alert for auroras after nightfall tomorrow.”
Update:  The site subsequently reported that the storm hit Earth today at 2000 UT (4 pm EDT), earlier than expected and with “So far . . . little geomagnetic activity.”

Risk monitoring 13 Sept.

The Monday Daily Orbit Update MPEC (DOU) has two positions for 2004 RJ9 reported from Kitt Peak yesterday morning, and today both NEODyS and JPL removed their remaining impact solutions for this object, which is estimated to be on the order of 400 meters/yards wide.

The DOU has three positions reported for intruder 2004 RU109 from LINEAR in New Mexico, yesterday morning within the discovery arc. Today JPL very slightly lowered its risk assessment, and NEODyS posted this small object with a similar assessment. (See a confirmation image of 2004 RU109 and more info above.)

Also from LINEAR yesterday morning is observation of 2004 RF84, and both risk monitors lowered their risk ratings and cut the number of impact solution counts for this kilometer-size object.

Update:  The observing from Kitt Peak yesterday that got 2004 RJ9 removed from the risk lists today was done by Lynne Allen and J.J. Kavelaars. They are at the 4m Mayall Telescope following up Edgeworth-Kuiper Belt objects from the CFHT Legacy Survey “and had a short period where we needed a few extra targets.”