The tension rose as the spacecraft approached its destination, in the NASA control room in Pasadena. But everything went according to plans. Complete success. The impactor has hit the comet exactly were it was supposed to, at 1:53 a.m. ET July 4, 2005.

The images sent down were amazing. The comet burst into light, emitting a shower of ice, containing the all important particles that are now analyzed by the flyby spacecraft's instruments. The impact was bigger than everybody would have expected, according to the people in mission control. The initial pictures of the collision from Flyby showed a cone-shaped plume of debris spraying into space. The resulting crater was expected to range anywhere from the size of a large house to a football stadium and be between two and 14 stories deep.

Upon approaching the comet, the impactor was able to transmit images of the celestial body. Tempel 1 had actually an avocado shape, rather than a pickle, as previously thought. And what the scientist saw was more than they would have ever expected. The comet's surface was full of craters, ridges and other forms of rough terrain. The images' resolution was awesome, of just a few meters, so they'll be able to provide very accurate information regarding the comet's structure, the best we've had so far.

Among the challenges workers in mission control were facing at NASA's Jet Propulsion Laboratory in Pasadena was the probe's switch to autopilot two hours before the encounter, relying on computer software and thrusters to steer itself into the path of the comet. After the switch, software engineer Anne Elson said ground controllers had to make only minor corrections to the automated flight paths.

But what is this device? The impactor was a battery-powered craft that operated independently of the Deep Impact mothership for one day. After its release, the impactor took over its own navigation and manoeuvres into the path of the comet. It is operated solely by batteries, because it had to be fitted with heavy shielding, in order to prevent any accidents due to the debris in the comet's coma.

And the images keep coming. We'll keep you posted throughout the day regarding what images the flyby spacecraft sent down.