Tanpopo mission
Japanese astrobiology mission testing interplanetary life transfer.
The Tanpopo mission is a Japanese orbital astrobiology experiment that studies whether life, organic compounds, and particles from Earth can travel between planets while in low Earth orbit. It tests the panspermia hypothesis, which suggests microbial life and prebiotic organic compounds might naturally move through space. The mission’s name comes from the dandelion plant, whose seeds resemble lifeforms spreading across the cosmos.
From May 2015 to February 2018, the mission used the Exposed Facility on the outside of Kibo, the Japanese Experimental Module on the International Space Station. Researchers collected cosmic dust and exposed dehydrated microorganisms at an altitude of 400 kilometers. They used ultra-low density silica gel (aerogel) to capture particles, with a density of 0.01 g/cc for the top layer and about 0.03 g/cc for the base layer. Some aerogel collectors were replaced every one to two years until February 2018, when the last samples were retrieved. The official ISS experiment code is JAXA-EPO-Tanpopo, also referred to as JAXA Tanpopo or simply Tanpopo.
The principal investigator is Akihiko Yamagishi, leading a team from 26 universities and institutions in Japan, including JAXA. The mission aims to confirm whether extraterrestrial organic compounds helped generate the first life on Earth and to examine panspermia. If microbes are found at 400 kilometers, it would support the idea that terrestrial life could migrate between planets. The experiments also test if terrestrial microbes, such as those in aerosols, might temporarily exist in freeze-dried form at that altitude.
Three key microorganisms studied are *Deinococcus radiodurans*, *D. aerius*, and *D. aetherius*. Containers with yeast and other microbes were placed outside Kibo to see if they survive the harsh cold of space. By analyzing returned samples of exposed microbes and organic analogs, researchers investigate survival and changes during interplanetary transport. They also aim to capture organic compounds, including amino acids, drifting in space.
The mission’s objectives cover six topics: sources of organic compounds reaching Earth’s surface; how organic compounds on micrometeorites are exposed to space before returning; detecting terrestrial microbes at ISS altitude from volcanic eruptions, thunderstorms, meteorite impacts, and electromagnetic fields; survival of certain micr
- field
- Astrobiology
- nationality
- Japan
- principal_investigator
- Akihiko Yamagishi
- institution
- JAXA and 26 universities and institutions in Japan
- mission_duration
- May 2015 through February 2018
- location
- Exposed Facility on Kibo module, International Space Station
- known_for
- Testing panspermia hypothesis and survival of microbes in space
Lore & Background
The Tanpopo mission collected cosmic dust and exposed dehydrated microorganisms outside the International Space Station at an altitude of 400 km from May 2015 through February 2018. It used ultra-low density silica gel (aerogel) with two densities—0.01 g/cc for the upper layer and ~0.03 g/cc for the base layer—to capture particles. The aerogel collectors were replaced every one to two years, with the last samples retrieved in February 2018 and returned to Earth for analysis.
Reader's Guide
The Tanpopo mission is significant for providing direct experimental data on the panspermia hypothesis, which proposes that life can spread between planets via meteoroids, comets, or cosmic dust. By exposing Deinococcus species (including D. radiodurans, D. aerius, and D. aetherius) and other microbes to the harsh environment of low Earth orbit, the mission demonstrated that some clumps of microorganisms can survive for at least one year in space, and specifically that Deinococcus radiodurans survived three years in outer space. These findings support the notion that life could be transported interplanetarily. Additionally, the mission captured organic compounds such as amino acids and analyzed mineralogy of micrometeoroids, contributing to understanding the sources of prebiotic organic compounds on early Earth. The ongoing analyses of captured particles, including PCR amplification and DNA sequencing, continue to inform astrobiology and the search for life beyond Earth.
Did You Know?
- The mission was named after the dandelion plant because its seeds evoke the image of seeds of life spreading through space.
- Tanpopo exposed Deinococcus radiodurans to outer space for up to three years (2015–2018), with survival results published later, such as in 2020.
Frequently Asked Questions
What is the Tanpopo mission?
It is a Japanese astrobiology experiment that flew on the International Space Station to examine whether microorganisms, organic molecules, and tiny particles could survive in low-Earth-orbit vacuum and potentially travel between planets naturally.
Who leads the Tanpopo mission and who is behind it?
Akihiko Yamagishi serves as principal investigator, and the project is a joint effort between JAXA and 26 Japanese universities and research institutions.
Where was the Tanpopo experiment mounted and how long did it run?
It was installed on the Exposed Facility on the exterior of Kibo, Japan's module on the ISS, and operated from May 2015 through February 2018.
What hypothesis does the Tanpopo mission test?
It probes the panspermia concept, asking whether microbial life or prebiotic organic compounds could be carried through space from one planetary body to another without any human-made spacecraft.
Why is the mission named "Tanpopo"?
The name is drawn from the dandelion, whose light seeds scatter on the wind — a fitting metaphor for life or organic material drifting across the cosmos from one world to another.
More in Astrobiology space missions 1-24
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