Page:Illustrated Astronomy.pdf/56

 • • • AT-HOME EXPERIMENT

How are craters formed?

You are going to see the differences between the impacts and recognize which ones were bigger meteors or where did they come from to create the many craters of the Moon.

Materials:

· 1 plastic bowl · 1 strainer · 3 kilos of flour · 1 cup of chocolate powder · You can find some other colored powder if you want

Step by step:

· Pour the 3 kg of powder into the bowl. Get at least 5 cm of thickness · Powder the chocolate over with a strainer · Throw different stones but in different sizes and with different speeds and angles. · Look at the results and compare them with real images of Moon’s craters. · You can try the experiment more times and add powders of different colors besides the chocolate.

This small rocky world, which tells us a story full of impacts, orbits the Earth in 27.32 days. It is called the sidereal period. As the Earth revolves around the Sun, the time between two identical lunar phases is known as the synodic period, and it lasts 29.53 days.

Perhaps, you may notice the shape or shapes of the Moon that we see are always the same way. That is because the Moon always shows the same face to Earth, so we always see the same half of it.

When a celestial object is showing the same face to another is called synchronous rotation, which means that its rotational and orbital periods are the same. In the case of the Earth with the Sun, it doesn’t happen because the Earth rotates 365.25 times per orbit.

The fact that we always see the same face of the Moon made us jump into the conclusion that it has a dark side. There is indeed a side we can’t see from Earth, but that doesn’t mean that it doesn’t get any light and it is always dark because of the Sun lights up every inch of the Moon in different moments of the lunar phase. For instance, during the New Moon phase, the Sun is entirely lightning up the side that we can’t see.



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