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Activity 3: Trip to the Sun - Journey to the Sun Page 2 of 3  
 
Getting to the Sun
Some people think that the Sun is only a short journey from the Earth. But distances, even within the solar system, are very large. If the Earth were represented by a ball a foot in diameter, the center of the Sun would be over two miles away. Getting to the Sun takes time. With today’s rocket technology, the journey will take several years.


 
 
Protection from the Sun's Energy
Now suppose you're on course for the Sun. How can you avoid damage caused by the Sun’s intense light? The designers of the Solar Probe have decided to use a large shield to protect the spacecraft from damage. This shield places the spacecraft in the shade. The diagram to the left shows what the Solar Probe spacecraft will look like.

The large black oval is the shield. The front of this shield casts a large shadow which protects the spacecraft from the intense sunlight. The back of the shield doubles as a large antenna for radioing the information back to Earth! Most of the instruments on board are located in the retractable tail. The materials which make up the shield need to be tested to be sure that they can withstand the intense light (which creates heat) of the Sun without melting or even boiling off into space. The boiling off process would weaken the shield. It would also produce a material called plasma that would confuse the instruments aboard the spacecraft which are trying to measure plasma material boiled off from the Sun’s outer layers.

  An artists rendering of the Solar Probe space craft approaching the active Sun
An artists rendering of the Solar Probe space craft approaching the active Sun
 
Plasma, in the astronomical sense of the term, consists of electrically charged material at very high temperatures. The temperature is so hot that atoms cease to exist and become free charged nuclei and electrons. It it completely different from blood plasma, the liquid part of our blood.





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