Nasa probe strikes Comet Tempel 1
US space agency (Nasa) scientists are celebrating after seeing a probe crash into the heart of a comet.
The washing machine-sized "impactor" collided with Comet Tempel 1 at a relative speed of 37,000km/h, throwing up a huge plume of icy debris.
The probe's mothership, the Deep Impact spacecraft, watched the event from a safe distance, sending images to Earth.
Dr Don Yeomans, a Nasa mission scientist, was ecstatic: "We hit it just exactly where we wanted to.
"The impact was bigger than I expected, and bigger than most of us expected. We've got all the data we could possibly ask for."
Comets - giant "dirty snowballs", as some have called them - are believed to contain materials that have remained largely unchanged since the formation of the Solar System 4.6 billion years ago.
Scientists hope that by getting "under the skin" of Comet Tempel 1, they can gain new information on the Solar System's original composition and perhaps even how life emerged in our corner of the Universe.