# Mercury (DD-133)

> Mercury, the closest planet to the Sun, has almost no atmosphere (only a thin exosphere) to trap heat. Its daytime surface reaches about 430 °C (800 °F), hot enough to melt lead, while nights fall to about -180 °C (-290 °F). That is the largest day-night swing of any planet. Its slow rotation also stretches each day: a solar day lasts about 176 Earth days. Despite the heat, radar and the MESSENGER spacecraft found water ice in permanently shadowed craters near the poles. The footage shows images of Mercury and the Sun, with the presenter.

- Department: Space
- First published: 2023-12-21
- Last updated: 2023-12-21
- Permalink: https://detailenjoyer.com/case/mercury/
- Author: Marcus Easterling (DetailEnjoyer), The Detail Department

## Quick facts

- **DD-133-F01**: Mercury has only a thin exosphere. _(Write-up · Exhibit A (No atmosphere))_
- **DD-133-F02**: Days reach about 430 °C. _(Write-up · Exhibit B (430 °C days))_

## Write-up

Mercury swings by about 600 °C between day and night. With almost no atmosphere, it can't hold heat.

1. **No atmosphere**: Mercury has only a thin exosphere.
2. **430 °C days**: Days reach about 430 °C.
3. **-180 °C nights**: Nights fall to about -180 °C.
4. **Long solar day**: A solar day lasts about 176 Earth days.
5. **Polar ice**: Shadowed polar craters hold water ice.

## Related case files

- [Cosmic Freezer (DD-752)](https://detailenjoyer.com/case/coldest-place-universe-v2/): I linked more extreme cold
- [Venus (DD-132)](https://detailenjoyer.com/case/venus/): I paired the two inner planets with extreme days
- [Oxidized Aluminum (DD-271)](https://detailenjoyer.com/case/oxidized-aluminum/): I linked more on the element

## Reel vs. record

- **Note**: 'Temperatures plummet to approximately 290 degrees Fahrenheit': it should be -290 °F; the caption drops the minus sign but the voiceover says 'negative'.

## Video: Mercury: Mercury Swings by About 600 °C Between Day and Night

- Duration: 25.7 s · Published: 2023-12-21
- File: https://detailenjoyer.com/assets/videos/C1Hre8KOUfh.mp4

### Transcript

Mercury the closest planet to the sun has extreme temperature variations due to its lack of a substantial atmosphere to retain heat. DID YOU KNOW? During its daytime temperatures can soar up to around 800 degrees Fahrenheit or 430 degrees Celsius, hot enough to melt lead. However, during its nighttime temperatures plummet to approximately 290 degrees Fahrenheit or negative 180 degrees Celsius, making it one of the most extreme temperature differences in our solar system. NOW YOU KNOW!

## Questions & answers

**Q: Why can't Mercury hold heat?**  
A: Only a thin exosphere. _(Source: Write-up · Exhibit A (No atmosphere) · Wikipedia: Mercury (planet))_

**Q: How hot do days get?**  
A: Hot enough to melt lead. _(Source: Write-up · Exhibit B (430 °C days) · Wikipedia: Mercury (planet))_

**Q: How cold do nights get?**  
A: About -290 °F. _(Source: Write-up · Exhibit C (-180 °C nights) · Wikipedia: Mercury (planet))_

**Q: How long is a solar day?**  
A: Slow rotation. _(Source: Write-up · Exhibit D (Long solar day) · Wikipedia: Mercury (planet))_

**Q: Where is there ice on Mercury?**  
A: Found by radar and MESSENGER. _(Source: Write-up · Exhibit E (Polar ice) · Wikipedia: Mercury (planet))_

## Sources

- [Wikipedia: Mercury (planet)](https://en.wikipedia.org/wiki/Mercury_%28planet%29)

## Cite this case file

Easterling, Marcus. "Mercury." The Detail Department (DetailEnjoyer), case file DD-133, last updated Dec 21, 2023. https://detailenjoyer.com/case/mercury/