For thousands of years comets had been a mystery toS1.______man. They travel across the sk

For thousands of years comets had been a mystery to S1.______

man. They travel across the sky very fast and have a

bright "tail" of burnt gas. The comet Tempel 1 has an S2.______

orbit far outside the orbit of the furthest planet in our

solar system, Pluto. It has had been there for 4.6 billion years, S3.______

133 million kilometres from Earth. Last week

a little American spacecraft crash into Tempel 1. S4.______

The spacecraft had a camera and it took a photograph

of the comet every minute after it finally crashed into S5.______

its surface. The space mission to Tempel 1 cost $335

million and was called Deep Impact. Spacecraft was S6.______

travelling at 37,000 kilometres per hour when it hit the comet

and the crash completely destroying the spacecraft. But before S7.______

it hit the comet, the spacecraft took some amazingly photographs. S8.______

The last one was a close-up picture the spacecraft spent S9.______

just 3 seconds time before it crashed into the comet. S10.______

【S1】