# Microscopic Extremophiles (DD-307)

> Tardigrades were first described in 1773 and named 'slow walkers' three years later; about 1,500 species are known. Researchers have exposed them to space on the FOTON-M3 mission, and a capsule of dried tardigrades crashed on the Moon with the Beresheet lander, while proteins such as Dsup help explain how they shield their DNA.

- Department: Nature (also Science)
- First published: 2024-08-24
- Last updated: 2024-08-24
- Permalink: https://detailenjoyer.com/case/microscopic-extremophiles/
- Author: Marcus Easterling (DetailEnjoyer), The Detail Department

## Quick facts

- **DD-307-F01**: They are called water bears. _(Write-up · Exhibit A (Little water bear))_
- **DD-307-F02**: Usually 0.3 to 0.5 mm long. _(Write-up · Exhibit A (Little water bear))_

## Write-up

Tardigrades have been studied since the 18th century, but the molecules that make them so hard to kill were only identified recently, and their toughness has since been tested on and off Earth.

1. **Little water bear**: German zoologist Johann August Ephraim Goeze first described them in 1773 as 'little water bears', and in 1776 Lazzaro Spallanzani named them Tardigrada, meaning slow walkers.
2. **Tested in orbit**: In 2007, dehydrated tardigrades and eggs on the FOTON-M3 mission were exposed to space vacuum and solar ultraviolet light for 10 days.
3. **Crashed on the Moon**: In 2019 a capsule of tardigrades in a cryptobiotic state was aboard the Israeli lunar lander Beresheet, which crashed on the Moon.
4. **A DNA shield**: A protein called Dsup ('damage suppressor') binds to nucleosomes and protects tardigrade DNA from radiation damage caused by hydroxyl radicals.
5. **Many species**: There are about 1,500 known tardigrade species, and the largest can reach 1.3 mm in length.

## Related case files

- [Argyroneta Aquatica (DD-670)](https://detailenjoyer.com/case/argyroneta-aquatica/): I linked another tiny survivor

## Reel vs. record

- **Note**: None needed.

## Video: Microscopic Extremophiles: Tardigrades Can Survive the Vacuum of Space

- Duration: 27.4 s · Published: 2024-08-24
- File: https://detailenjoyer.com/assets/videos/C_EPtoEpRgO.mp4

### Transcript

Tardigrades, often called water bears or moss piglets, are microscopic creatures known for their incredible resilience. Measuring only about 0.3 to 0.5 millimeters long, these tiny organisms can survive extreme conditions that would be fatal to most lifeforms, such as intense heat, freezing temperatures, radiation and even the vacuum of space. Tardigrades achieve this by entering a state called cryptobiosis, in which they lose almost all of their water content and slow down their metabolism to nearly undetectable levels! NOW YOU KNOW!

## Questions & answers

**Q: What are tardigrades called?**  
A: Also moss piglets. _(Source: Write-up · Exhibit B (Tested in orbit) · Wikipedia: Tardigrade)_

**Q: How long are they?**  
A: Microscopic. _(Source: Write-up · Exhibit E (Many species) · Wikipedia: Tardigrade)_

**Q: What can they survive?**  
A: When dried out. _(Source: Write-up · Exhibit E (Many species) · Wikipedia: Tardigrade)_

**Q: What is their survival state called?**  
A: Hidden life. _(Source: Write-up · Exhibit C (Crashed on the Moon) · Wikipedia: Tardigrade; Wikipedia: Cryptobiosis)_

**Q: What do they lose?**  
A: They dry out. _(Source: Write-up · Exhibit A (Little water bear) · Wikipedia: Cryptobiosis)_

## Sources

- [Wikipedia: Tardigrade](https://en.wikipedia.org/wiki/Tardigrade)
- [Wikipedia: Cryptobiosis](https://en.wikipedia.org/wiki/Cryptobiosis)

## Cite this case file

Easterling, Marcus. "Microscopic Extremophiles." The Detail Department (DetailEnjoyer), case file DD-307, last updated Aug 24, 2024. https://detailenjoyer.com/case/microscopic-extremophiles/