Why are the lunar mountains smoothly rounded rather than having sharp, pointed peaks (as they were almost always depicted in science-fiction illustrations and films before the first lunar landings)?

The lunar mountains are smoothly rounded rather than having sharp, pointed peaks due to several reasons:

1. Lack of Atmosphere: Unlike Earth, the Moon doesn't have a significant atmosphere. On Earth, the weathering and erosion caused by wind and water can create sharp, pointed peaks. However, on the Moon, these processes do not occur, which results in the mountains having a more rounded appearance.

2. Impact Cratering: The Moon's surface is constantly bombarded by meteorites. These impacts create craters and can cause the lunar mountains to have a more rounded appearance. The force of these impacts can also cause the lunar rock to melt and then solidify again, which can also contribute to a smoother, more rounded appearance.

3. Lunar Regolith: The Moon's surface is covered by a layer of loose, fragmented material known as lunar regolith. This regolith is created by the constant meteorite impacts and can help to smooth out the lunar mountains.

4. Age: The Moon's surface is very old and has been exposed to space for billions of years. Over this time, the constant meteorite impacts have helped to smooth and round the lunar mountains.

So, the combination of these factors results in the lunar mountains having a smoother, more rounded appearance rather than sharp, pointed peaks.