# Lunar Topography (DD-385)

> The Moon's craters were made by impacts of asteroids, comets and meteoroids over billions of years. Many large basins date to an early period of heavy bombardment, sometimes called the Late Heavy Bombardment, often placed about 4.1 to 3.8 billion years ago. The South Pole-Aitken Basin, about 2,500 kilometers across, is the largest. Without air or water, there is little erosion to wear them away. The footage shows close-up views of the lunar surface.

- Department: Space
- First published: 2024-11-22
- Last updated: 2024-11-22
- Permalink: https://detailenjoyer.com/case/lunar-topography/
- Author: Marcus Easterling (DetailEnjoyer), The Detail Department

## Quick facts

- **DD-385-F01**: Asteroids and comets. _(Write-up · Exhibit A (Impacts))_
- **DD-385-F02**: About 4.1 to 3.8 billion years ago. _(Write-up · Exhibit B (Bombardment))_

## Write-up

With no air or water, the Moon's craters barely erode. Its largest basin is about 2,500 kilometers wide.

1. **Impacts**: Asteroids and comets.
2. **Bombardment**: About 4.1 to 3.8 billion years ago.
3. **Largest**: South Pole-Aitken Basin.
4. **Size**: About 2,500 km.
5. **Erosion**: No wind or water.

## Related case files

- [Lunar Roving (DD-609)](https://detailenjoyer.com/case/lunar-roving/): I linked more on the Moon

## Reel vs. record

- **Note**: The Reel dates the Late Heavy Bombardment to about 4.5 billion years ago; it is usually placed about 4.1 to 3.8 billion years ago.

## Video: Lunar Topography: With No Air or Water, the Moon's Craters Barely Erode

- Duration: 29.9 s · Published: 2024-11-22
- File: https://detailenjoyer.com/assets/videos/DCrlTwwJnnu.mp4

### Transcript

Did you know? The moon's craters were formed primarily by impacts from asteroids, comets, and meteorites over billions of years. During the early history of the solar system, around 4.5 billion years ago, a period known as the Late Heavy Bombardment saw intense collisions between celestial bodies. These impacts created the moon's characteristic craters, ranging in size from small pits to massive basins, like the South Pole-Aitken Basin. Since the moon lacks an atmosphere, there is no erosion from wind or water to smooth out these features, allowing the craters to remain relatively unchanged over time. NOW YOU KNOW!

## Questions & answers

**Q: What made the craters?**  
A: Collisions. _(Source: Write-up · Exhibit A (Impacts) · Wikipedia: Lunar craters)_

**Q: Largest basin?**  
A: Far side. _(Source: Write-up · Exhibit B (Bombardment) · Wikipedia: Lunar craters)_

**Q: Why do craters last?**  
A: No atmosphere. _(Source: Write-up · Exhibit C (Largest) · Wikipedia: South Pole–Aitken basin)_

**Q: When was the Late Heavy Bombardment?**  
A: Early. _(Source: Write-up · Exhibit D (Size) · Wikipedia: South Pole–Aitken basin)_

**Q: About how wide is South Pole-Aitken?**  
A: Huge. _(Source: Write-up · Exhibit E (Erosion) · Wikipedia: Lunar craters)_

## Sources

- [Wikipedia: Lunar craters](https://en.wikipedia.org/wiki/Lunar_craters)
- [Wikipedia: South Pole–Aitken basin](https://en.wikipedia.org/wiki/South_Pole%E2%80%93Aitken_basin)

## Cite this case file

Easterling, Marcus. "Lunar Topography." The Detail Department (DetailEnjoyer), case file DD-385, last updated Nov 22, 2024. https://detailenjoyer.com/case/lunar-topography/