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

Today's issue status: done

• News briefs – Deep Impact, comet news,
  FMOP discoveries & HST news
• Risk monitoring – JPL has removed 2004 HD2 & 2004 HK12 + NEODyS has posted 2004 HE12
  

Cover: Rafael Ferrando caught 2004 GE2 on the 19th at Pla D'Arguines Observatory in Spain. With an observing arc of more than nine days now, this object continues to linger on the JPL Current Impact Risk pages with a single low-rated impact solution at the beginning of the next Century (see below). Its diameter is estimated by JPL at roughly 180 meters/yards, and it will come to within about 12.9 lunar distances of Earth tomorrow.

Deep Impact:  The Deep Impact mission April newsletter has a photo of stacking the impactor and flyby vehicles, new paper models, and a teacher interview. Target 9P/Temple 1 is reported to have been observed by the Spitzer Space Telescope "just recently," and Hubble will observe it "in early May."

Comet news:  Jonathan Shanklin in England reports that this morning he spotted C/2004 F4 (Bradfield) with binoculars, noting that it "was nearly stellar with hints of a tail."

Terry Lovejoy has posted a photo of C/2001 Q4 (NEAT) with the Large Magellanic Cloud from yesterday and two versions of a C/2002 T7 (LINEAR) photo from the day before. He notes both comets can be seen now with the unaided eye in dark skies. John Bortle commented to the Comets Mailing List that C/2002 T7 appears to be a "classic dust-starved comet. Assuming images reasonably correspond to visual light, there seems to [be] no indication of any normal Type II dust tail, which should be very apparent at this r value."

Hubble news:  As Space.com noted yesterday, tomorrow, Saturday, is the 14th anniversary of the Hubble Space Telescope launch. A Sky & Telescope article today, "Hubble Study Gets Under Way," says, "With any luck, [a National Academy of Sciences blue-ribbon panel's] deliberations will bring an end to months of rancorous debate about Hubble's future." In an Aviation Week report yesterday, "Robotic Hubble Servicing Is Feasible, NASA Decides," NASA's chief space scientist, Ed Weiler, is quoted as saying that NASA has to put the proposal process in motion before the NAS panel report is received. "If we're going to do a robotic mission [in 2007-2008], we've got to get people under contract this fall." See also a BBC report and especially the Baltimore Sun's anecdotal "A glimmer of hope for Hubble" today.

Risk monitoring 23 April

The Friday Daily Orbit Update MPEC (DOU) has a set of 13 observations of 2004 HK12 from LINEAR in New Mexico yesterday morning. This set spans 62 minutes within the original 1.168-day observing arc with its ten discovery and confirmation positions. Today JPL removed all impact solutions for this object, which had originally totalled 220.

The DOU carries observations of 2004 HD2 from last night from KLENOT in the Czech Republic and Great Shefford Observatory in England. And today JPL removed the last three impact solutions for this object.

NEODyS today posted 2004 HE12, for which the DOU does not have new observations. (The MPC Last Observation page shows that the Spacewatch 1.8m telescope in Arizona caught it this morning.)

The DOU does have new data for 2004 HZ, reported from KLENOT Wednesday night and LINEAR yesterday morning. Today JPL cut its solution count for this small object from 132 to 61 (all but one within the NEODyS time horizon) and raised its overall risk

ratings. NEODyS also raised its ratings and went from 78 to 116 solutions. And both monitors now have their first solution in 2017 instead of 2008.

more risk monitoring >>

<< continued from panel 1

Two objects only listed by JPL, and each with only a single low-rated solution, are reported in the DOU — 2004 GE2 from KLENOT yesterday morning and Great Shefford early today, and 2004 HF12 from KLENOT Wednesday night, LINEAR yesterday morning, and Great Shefford last night. Today JPL made slight changes in the assessments, lowering 2004 GE2 and raising 2004 HF12.

2004 HM is a small object also only listed by JPL and is in the DOU, reported from yesterday morning by KLENOT and the Catalina Sky Survey (CSS) in Arizona and this morning by Great Shefford. Today's revised risk assessment is essentially unchanged.

Both monitors have 2004 HQ1 listed and it was caught by KLENOT and Great Shefford last night. NEODyS very slightly raised its low risk ratings and added a few impact solutions, while JPL slightly lowered its already low ratings.

So, besides 2004 HE12, the one other object in current view that has impact solutions but isn't

reported in today's DOU is 2004 HW, and, like HE12, it is reported by the Last Observation page as having been observed with the Spacewatch 1.8m telescope this morning.

Update:  JPL has revised its 2004 HW risk assessment based on the existing observation arc, cutting down to just one low-rated impact solution in 2074.
      JPL has just posted 2000 TU28 based on its 30.106-day observing arc from late 2000. This may seem a bit odd until one notes that the single low-rated impact solution is for 13 April 2104. This object, estimated by JPL at 280 meters wide, just came within Sentry's hundred-year time horizon.