Read this news article and pay particular attention to the orange words.
Ten years ago the European Space Agency launched a robot probe called Philae. Its mission was to travel six billion kilometres and land on a four kilometre wide comet that travels 130,000 kilometres an hour.
Amazingly, the Philae probe successfully landed on the surface of the comet seven hours after descending from its mother ship Rosetta.
Comets, which scientists think are older than the Earth, may contain materials that will help us understand how life started. It's likely that icy comets brought most of the water in today’s oceans to Earth and the organisms that evolved into all life forms.
The comet is called 67/Churyumov-Gerasimenko, named after its discoverers who first spotted it in 1969.
It was chosen as a landing target from the hundreds of comets flying around the Solar System because it would be in the right place at the right time, and it has the best conditions for research. As the comet approaches the Sun its icy surface starts to evaporate. The instruments on Philae will study the water, dust and gas that are released over the period of one year.
The only glitch in the process has been the apparent failure of the probe’s two harpoons to fasten the craft down.
The £1bn ($1.58bn) Rosetta mission is the biggest and most ambitious project in the history of the European Space Agency.
Now choose the correct definitions of the key words:
