Abstract

The Rosetta space probe launched 10 years ago by the European Space Agency (ESA) arrived recently (November 12, 2014) at the site of the comet known as 67P/Churyumov-Gerasimenco after a trip of 4 billions miles from Earth. After circling the comet, Rosetta released its precious load : the lander Philae  packed with 21 different scientific instruments for the study of the comet with the main purpose : the origin of our solar system and possibly the origin of life on our planet.

Our plan is rather a modest one since all we want is to get , by calculations, specific data concerning the comet and its lander.
We shall take a simplified model and consider the comet as a perfect solid sphere to which we can apply Newton's laws.

We want to find:

I- the acceleration on the comet surface ,
II- its radius,
III- its density,
IV- the velocity of Philae just after the 1st bounce off the comet (it has bounced twice),
V- the time for Philae to reach altitude of 1000 m above the comet .

We shall compare our findings with the already known data to see how close our simplified mathematical model findings are to the duck-shaped comet already known results.
It turned out that our calculations for a sphere shaped comet are very close to the already known data.

Conclusion

Even with a shape that defies the application of any mechanical laws we can always get very close to reality by adopting a simplified mathematical model in any preliminary study of a complicated problem.