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3

"Protection" isn't the only effect of Earth. Here is a different POV: Earth may have accelerated impactors by gravity assist. A different approch is the thinner crust, as suggested for the near side, which may have allowed asteroids to penetrate Moon's crust, such that lava could flow into the basins, or which may have favoured volcanism on the near side ...

3

The two hemispheres have distinctly different appearances, with the near side covered in multiple, large maria (Latin for 'seas,' since the earliest astronomers incorrectly thought that these plains were seas of lunar water). The far side has a battered, densely cratered appearance with few maria. Only 1% of the surface of the far side is covered by maria, ...

3

This experiment is still done frequently, but you need a powerful pulsed laser, precise pointing (error below about 20 arc seconds) and a sensitive detector. Amateurs will fail most likely, because they won't get access to an appropriate equipment. Here is a youtube video, which may give an impression of how difficult it is to perform the experiment.

5

The velocity of the impactor of tens of kilometers per second provides enough energy to heat the impactor and parts of the target to several thousands of Kelvins, so that parts are converted to plasma or to vapor, at least. According to Planck's law the color at these temperatures is white or bluish. According to the Stefan Boltzman law the total emitted ...

4

If we take 6371.0 km as the mean radius of Earth, an apogee of Moon of 405503 km, and a perigee of 363295 km, we get ratios of 6371.0 km / 405503 km = 0.01571 = sin 0.9002° resp. 6371.0 km / 363295 km = 0.01754 = sin 1.005°. So on both sides of Earth between $$40030\mbox{ km}\cdot 0.9002°/360°=100\mbox{ km}$$ and 40030\mbox{ km}\cdot 1.005°/360° =112\mbox{ ...

8

On any given day, you see the moon rise in the east and (apparently) travel across the sky from your left to the right; therefore, you would assume (incorrectly) that the leading edge of the moon's movement must be to the right. That is not correct. The apparent motion you are seeing is predominantly from the Earth's ~24 hour rotation. But the orbit of ...

1

A little further research, and I found out that the basic principle, from which several variations derive, is to take the sum of the squares of the difference between adjacent pixels, to get a score. The principle is that a higher quality picture has a higher probability that there will be significant differences in adjacent pixel values, i.e. that there ...

1

In 28 days the moon travels 1,499,070 miles so that is 53,430 miles in a day, and 2,267 miles per hour. The Moon is fast at 2,267 miles per hour. Guess we only get there in our dreams. Most of us think the moon goes around us every 24 hours because the Earth is spinning. Wait! the earth is spinning? Yes, and makes the fast moving Moon seem like it and ...

1

February 3, 2014 has been short (three days) after new moon. The moon is then about 40 degrees or about 3 hours behind the sun. Hence, what you observed is quite normal, in Europe, too. The only difference is, that the moon looks to the other side when seen from the southern hemisphere. Here, for 2014, a moon phase calendar of the northern hemisphere.

2

@adrianmcmenamin Has the right idea here. These objects he is referring to are called Trojans, and are defined to be: a minor planet or natural satellite (moon) that shares an orbit with a planet or larger moon, but does not collide with it because it orbits around one of the two Lagrangian points of stability (trojan points), L4 and L5, which lie ...

6

The strength of the Earth's gravitational field compared to the Moon and the Sun is not enough to capture and hold satellites - there are too many disruptive forces that would rip them away over time. However there are some objects at the Lagrangian points - the points where the gravitational fields of the Earth and other objects are equal and so it is ...

2

I created the spreadsheet. It's a bit complicated, to say the least. Initially I was inputting the formulas by hand from the book I cited in the video, but the process was rather error-prone so I ditched those tables and simply scanned the pages electronically and used the numbers from the scans to construct the tables of the Fourier series used to compute ...

1

It appears that way because there is more land reflecting sun light to your retina at the edges. This is because the Moon is a sphere. As you move your eye from the center of the moon towards the edges, you are scanning over increasingly more amounts of reflective rock. Hence, the edges appear very bright relative to the center. It's all about surface ...

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