New laboratory experiments reveal that salt-enriched water could flow long enough on airless worlds to carve the distinctive channels observed on the giant asteroid Vesta, challenging previous assumptions about liquid behavior in space.
Published in Planetary Science Journal | Estimated reading time: 4 minutes
When NASA’s Dawn spacecraft captured images of deep channels carved into asteroid Vesta’s crater-pocked surface, scientists faced a puzzle: How could liquid flow long enough to create these features on a body exposed to the vacuum of space? A new NASA-funded study provides a surprisingly simple answer – table salt.
“Not only do impacts trigger a flow of liquid on the surface, the liquids are active long enough to create specific surface features,” says Jennifer Scully, planetary scientist at NASA’s Jet Propulsion Laboratory (JPL) and project leader of the study. The key question driving their research was determining how long such flows could persist before freezing in the harsh space environment.
Using JPL’s specialized vacuum chamber called DUSTIE (Dirty Under-vacuum Simulation Testbed for Icy Environments), researchers recreated Vesta-like conditions that would occur after meteoroid impacts. While pure water froze almost instantly under vacuum conditions, briny solutions remained liquid for at least an hour – more than enough time to form the gullies observed on Vesta, which scientists estimate required about 30 minutes to develop.
The research team, including lead author Michael J. Poston of the Southwest Research Institute, discovered that these salty liquids could form protective “lids” – frozen top layers that shield the flowing liquid underneath from space’s vacuum. This process mirrors how Earth’s lava travels farther in tubes than when exposed to cool surface temperatures.
These findings don’t just illuminate Vesta’s geological history. They contribute to our broader understanding of how liquids behave across the solar system, from potential mud volcanoes on Mars to ice volcanoes on Jupiter’s moon Europa. The Dawn mission, which studied Vesta for 14 months between 2011-2012, continues to yield insights about the complex processes shaping our cosmic neighborhood.
Glossary
- Brine
- A solution of water containing high concentrations of salt, capable of remaining liquid under conditions where pure water would freeze.
- DUSTIE
- The Dirty Under-vacuum Simulation Testbed for Icy Environments – a specialized chamber used to recreate space-like conditions for scientific experiments.
- Flow Formations
- Channels or gullies carved into a celestial body’s surface by flowing material, whether liquid or dry debris.
Test Your Knowledge
How long did briny liquids remain fluid in the DUSTIE experiments?
The salty solutions stayed fluid for at least an hour under vacuum conditions.
What is the estimated time required to form the gullies observed on Vesta?
Scientists estimate the gullies required up to a half-hour to form.
What is the protective mechanism that allows briny liquids to flow longer on airless bodies?
The brines form “lids” – frozen top layers that protect the flowing liquid underneath from the vacuum of space.
How does the brine flow mechanism on Vesta compare to geological processes on Earth?
The process is similar to how lava flows farther in lava tubes than when exposed to cool surface temperatures on Earth.
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