Articles on Mistaken Identification of ESA Rosetta Spacecraft as Asteroid

Image description: Rosetta’s navigation camera (NAVCAM) took this shot of Earth right after Rosetta’s closest approach to our planet. The picture was taken at 22:56 CET on 13 November, as Rosetta’s second Earth swing-by concluded, while the spacecraft was flying at a height of about 6250 km from the surface. Credits: ESA.


Image description: An artist's rendition of Rosetta's second close approach to Earth on Nov. 13, 2007. The swing-by is Rosetta's third major step on its 10-year journey to comet 67/P-Churyumov-Gerasimenko. Credit: C. Carreau/ESA.

From one of the articles...

The Minor Planet Center, the world clearinghouse for information about newly discovered asteroids, raised the alarm last week. In an email to professional observatories, they announced that a previously unknown asteroid would miss the Earth by just 5,600 kilometers.

The newly discovered space rock was given an official label by the MPC, which is run by the Smithsonian Astrophysical Observatory, Massachusetts, for the International Astronomical Union. Observations for 2007 VN84 were collected from astronomers around the world, to track the threatening celestial body. This would be one of the closest approaches ever by a sizable asteroid – its distance away being less than half the diameter of the Earth.

Then Denis Denisenko, of Moscow's Space Research Institute (IKI), made an interesting discovery. He noticed that the incoming asteroid's track matched that of the European space probe Rosetta on a scheduled flyby of Earth.

The Rosetta craft was launched from Europe's Guiana Space Center in early March of 2004; the purpose of the space probe is to place itself in low orbit around the comet Churyumov-Gerasimenko at a distance of 675 million kilometers from the sun. To get there, the billion-dollar craft will spend ten years boosting its velocity (using the gravity assist technique) with no fewer than three flybys of Earth and one of Mars.

Denisenko's discovery came none too soon; Britain's Royal Astronomical Society was preparing a bulletin for the media that would have been released on Monday.

"Near-Miss Asteroid Found to be Artificial"
Bill Christensen
Space.com
12 November 2007

Link: Article

From another article...

But the incident raises questions about how well the warning system works. The Minor Planet Center complains that, "this incident highlights the deplorable state of availability of positional information on distant artificial objects". This lack of a centralised database makes checking incoming objects against known space probes difficult.

"Astronomers defend asteroid warning mix-up"
Justin Mullins
NewScientist.com
13 November 2007

Link: Article