the hollow moon

we can see the moon basically every night, because of the bright colour, the moon is thought to be a sign of sullen and, somehow, romantic. people think all the time that we know awful a lot of it; well in some sense, we do know quite a lot, but do we really understand it? not really..... here are the reasons

1. Is moon our natural satellite?

We may think that moon is our natural satellite, if it is, it would be a pretty unordinary one. Check out the data below and you'll find out

· The diameter of the earth is 12756 km; the diameter of the moon is 3467 km which is 27% of the earth.

· The diameter of the Saturn is 120000 km; the diameter of the biggest satellite is 4500 km which is 3.75% of the Saturn.

· The diameter of the Jupiter is 142800 km; the diameter of the biggest satellite is 5000 km which is 3.5% of the Jupiter.

· The diameter of the Mars is 6787 km; the diameter of the biggest satellite is 23 km which is 0.34% of the Mars.

As you have probably noticed that the size proportion is no more than 5%, but the size of the moon is actually 27% of the earth, which I would conclude EXTRAORDINARY. If this cannot convincing, well, you’d better keep reading.

2. Moonquake experiments

· When Apollo No.11 got to the moon, it put a very sensible Moonquake detector on the surface; its sensitivity was so high that it can even detect the steps of the astronauts. At 4:15 American time on 20th of November, 1969. Apollo No. 12 hit the moon surface and hence caused a Moonquake. It lasted for 55min and it took 8min to reach the climax. It was like ringing a bell.

· The passengers of Apollo No. 13 did the same experiment again by using a remote control craft. This time, the Moonquake lasted for 3h 20min.

· According to a great amount of measurement, the scientists have finally concluded that there is a hard formation inside the moon which is approximately 40 miles thick. The sound can reach a speed of 6 miles per second in the material, if you’ve done GCSE physics, it is not hard to tell that the sound speed in rock definitely cannot be this high. But the spreading speed can easily reach 6miles per second if it is travelling in metals. Scientist speculated that there is a metal shell inside the moon and it is covered by 10 to 20 miles of rock.

3. Moon’s density argument.

· The average density of the moon is 3.33g/cm3, whereas the average density of the earth is 5.5 g/cm3, so the hypothesis is that the moon may be hollow.

· The rock density of the moon is 3.2 g/cm3; the rock density of the earth is 2.7 g/cm3, but the mass of the moon is only the half of the earth. Therefore the only possible explanation is that it is hollow.

In conclusion, the moon that we are familiar with is not familiar to us anymore. It is the time to discover a brand new moon.