Comets and our journey to one
Paxi the alien tells us about comets and the Rosetta spacecraft that flew to a comet called 67P.
What is a comet?
- It is an icy rock which flies around the sun. Scientists think the ice is frozen water and frozen gases.
- Some of their journey is near the sun where it is hot but some is very far away where space is very very cold. When it goes near the sun, the sun heats up the ice and the ice melts.
- In space, when ice melts it turns into gas.
- When the ice turns into gas, the gas forms a cloud around the icy rock.
- A comet can grow a long tail of gas and dust, which we can see from Earth.
- The tail can be millions of miles long, but each bit of dust is only as big as a grain of sand.
- Tricky words: 'Nucleus' means the icy rock middle of a comet. 'Coma' means the gas cloud around the comet.
It has taken people hundreds of years to discover things about comets. For over 30 years we have sent spacecraft into space to find out about comets.
How we have learned about comets
Rosetta arrives at the comet
After Rosetta had travelled for ten years, Rosetta arrived near the comet. The comet was between Mars and Jupiter.
First, Rosetta took pictures of the comet and examined the gas in the coma. Then, Rosetta released its lander (called Philae).
When Philae landed on the comet, it used the screws in its feet to fix itself to the comet so it wouldn't fall off. Philae sent back the first pictures from a comet's surface. Philae did experiments to find out more about comets. It found out what materials are in the icy nucleus. The ice isn't just frozen water!
First, Rosetta took pictures of the comet and examined the gas in the coma. Then, Rosetta released its lander (called Philae).
When Philae landed on the comet, it used the screws in its feet to fix itself to the comet so it wouldn't fall off. Philae sent back the first pictures from a comet's surface. Philae did experiments to find out more about comets. It found out what materials are in the icy nucleus. The ice isn't just frozen water!
Can you remember?
- Rosetta is a ___________
- Philae is a _____________ and it is the first to _________ on a comet.
- A comet is an ___________ that flies around the sun.
- When the comet flies near the sun, the sun heats up the _____ and it turns into ________.
- Comet 67P is shaped like a rubber ____.
- Rosetta and Philae travelled in space for ___ years.
- Rosetta met the comet between the planets ____ and _______.
- Philae's job was to find out what materials are in ____________.