Artist's impression of the Stardust spacecraft today, traveling with its Whipple Shields facing forward into the hypervelocity particle flow while closing in on comet 81P/Wild 2. Image courtesy of NASA/JPL.

daily news journal about
Asteroids, Comets & Meteors
Today's issue status: done

• Stardust at 81P/Wild 2
• News briefs
  – Iran meteor impact? & SOHO comets
• Risk monitoring

Stardust project manager Tom Duxbury told a news conference this afternoon in Pasadena that the mission had been planned on the assumption that cometary jets blend into a fairly uniform environment away from

Revised caption: JPL tells A/CC that both of these images are from the same navigation camera frame. The version at right has been enhanced to show the comet's jets. Early thinking is that the crater-like features in 81P/Wild 2's surface are sublimation "sink holes." Image courtesy of NASA/JPL.

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a comet, which was proven wrong with 81P/Wild 2 [link|alt]. "There were two significant jets that we barrelled right through." The spacecraft maintained communication throughout the flyby without interruption, however, and soon began downloading data and images, a process that will take until tomorrow night to complete.

The vehicle was closest to the comet at about 1940 UTC (2:40pm EST, 11:40am in Pasadena) today, a time during which Spaceflight Now had a running commentary. A NASA/JPL news release late today reports great satisfaction with the results, and all systems are reported to appear to have done their jobs to spec or better, including the navigation camera.

CNN had an Associated Press preview today in advance of the event. And local angles were taken at the Denver Post today, "Lockheed's year starts far away," and at the Fort Wayne News-Sentinel today, "Rocket science: Tom Duxbury's work on the Stardust project is expected to pay off today as it passes comet."

Comments were made on NASA TV during the flyby and in the news conference later about how much important help had been provided by several of the world's largest telescopes, including the 10m Keck and 200-inch Palomar, in the final navigation of Stardust to the comet. Those observations haven't been reported publicly through the Minor Planet Center yet, but an MPEC on December 25th carried 49 positions for 81P/Wild 2 contributed by amateur astronomers around the world with small telescopes: Ageo Observatory in Japan from December 12th and 22nd, Badlands Observatory in South Dakota from 16, 18-21 and 23-24 December, and Loomberah Observatory in Australia from the 24th, as well as JPL's Table Mountain Observatory in southern California from the 22nd.

Post-flyby coverage:

• Reuters UK "Out of this world snaps of comet" (3 Jan.)
• CNN "Spacecraft survives close encounter with comet"
• BBC "Stardust probe makes comet flyby"
• Bill Harwood of CBS, posted at Spaceflight Now, "Stardust intercepts comet to gather samples"
• Reuters "Spacecraft Survives Close Encounter with Comet"

Iran meteor impact?  Reuters UK has an article today, "Meteorite hits Iran":

“ A meteorite which hit Babol [Mazandaran province] on Friday morning caused only some minor damage to residential units," radio said. . .  [The] impact was felt up to one kilometre away. ”

SOHO comets:  As A/CC reported December 26th, the SOHO mission has resumed support for public discovery of comets from SOHO images over the Internet. Last night the Minor Planet Center issued MPEC 2004-A03, its first with SOHO comet discoveries since last August 1st. This new MPEC announces C/2002 W9 through C/2002 W14 (SOHO), discovered in late November 2002 with credits to five members of the public.

The Stardust spacecraft,
illustration courtesy of NASA/JPL.

Risk monitoring 2 Jan.

The Friday Daily Orbit Update MPEC (DOU) carries observations of 2003 YH136 from the Observatorio Astronomico de Mallorca (OAM) from this morning and of 2003 YK118 from Begues (Spain) and McCarthy (Connecticut) observatories from yesterday morning as well as one position reported by Guidestar Observatory in Germany the night of December 31st. Today both NEODyS and JPL slightly raised their risk ratings for 2003 YH136, and NEODyS raised its ratings for 2003 YH118 while cutting its count of impact solutions from 58 to two.

Today's DOU also carries new-found or restated observations of the small object (H=22.5) 2001 SB170 [link|alt] from NEAT's Mt. Palomar telescope from 23 September 2001 in mid-observing arc, and today JPL removed one of its three remaining impact solutions while very slightly raising its low risk ratings.

Update:  JPL has issued a new assessment for 2003 YK118, cutting from 108 impact solutions to just two, both within the NEODyS 2080 time horizon, and slightly lowering its risk ratings.