Brussels, 04 Jul 2005
171 days into its 172-day journey towards comet Tempel 1, the impactor of the NASA's Deep Impact spacecraft successfully encountered the comet at 7:52 am Central European Time on 4 July.
At release, Deep Impact was about 880,000 kilometres away from its quarry. This is a historical mission, the first time a human creation has deliberately hit a comet. Scientists hope the collision - and what comes out of it - will unlock the inner workings of comets, and provide them with a better understanding of the origins of Earth.
The Deep Impact spacecraft was composed of two probes mated together: 'flyby' and 'impactor'. Flyby is about the size of a small car and monitored the impact with the comet. It carries two cameras, a high-resolution one, tightly focused on the crater, and a medium-resolution camera, which is taking wider views.
Impactor is a washing machine-sized 372kg copper-fortified probe designed to produce maximum wallop when it hits the comet. It also carried a medium-resolution camera that recorded the probe's final moments before the collision.
Deep Impact mission controllers have confirmed the impactor's S-band antenna is talking to the flyby spacecraft. All impactor data, including the expected remarkable images of its final dive into the comet's nucleus, will be transmitted to the flyby craft - which will then downlink them to Deep Space Network antennas that are listening 134 million kilometres away.
While all is going as expected on the Deep Impact spacecraft, the comet itself is putting on something of a show. The 14-kilometer-long comet Tempel 1 displayed another cometary outburst on 2 July when a massive, short-lived blast of ice or other particles escaped from inside the comet's nucleus and temporarily expanded the size and reflectivity of the cloud of dust and gas (coma) that surrounds it. The 2 July outburst is the fourth observed in the past three weeks.
Three of the outbursts appear to have originated from the same area on the surface of the nucleus, but they do not occur every time that that area faces the Sun.
'The comet is definitely full of surprises so far and probably has a few more in store for us,' said Deep Impact Project Manager Rick Grammier of NASA's Jet Propulsion Laboratory, Pasadena, California. 'None of this overly concerns us nor has it forced us to modify our nominal mission plan.'
For further information, please consult the following web address: http://deepimpact.jpl.nasa.gov
Images from a camera aboard Deep Impact's impactor and flyby spacecraft can be watched in near-real time at http://www.nasa.gov/deepimpact