NASA-Funded Study Unveils Water Flow Mystery on Giant Asteroid Vesta.

 

NASA’s Dawn spacecraft captured this image of Vesta as it left the giant asteroid’s orbit in 2012, with the north pole centered in the frame.

In a groundbreaking study published in the Planetary Science Journal, scientists have shed light on the mysterious gullies observed on the asteroid Vesta, suggesting that these formations could be the result of ancient water flows in the vacuum of space. Known as “flow formations,” these channels challenge our understanding of how liquids can behave under extreme conditions.

Vesta, explored by NASA’s Dawn spacecraft, showcases numerous geological features, including deep gullies and sediment fans. Previously, these were thought to result from dry debris flows. However, the new research posits that meteoroid impacts might have melted subsurface ice, leading to short-lived but impactful water flows.

The Experiment:

At NASA’s Jet Propulsion Laboratory (JPL), researchers used a specialized test chamber, dubbed DUSTIE (Dirty Under-vacuum Simulation Testbed for Icy Environments), to simulate Vesta’s harsh conditions. They discovered that while pure water freezes almost immediately in a vacuum, water with sodium chloride (common table salt) can remain liquid for up to an hour or more. 

“These findings suggest that on Vesta, the presence of salt in the water could have allowed it to flow long enough to carve the gullies we observe,” said Jennifer Scully, the project leader from JPL. This time frame is significant because estimates suggest that the geological features on Vesta would require around half an hour to form.

Impact on Understanding:

The study not only provides insight into Vesta’s past but also extends our knowledge to other celestial bodies like Ceres, where Dawn also found evidence of subsurface brines. The experiments demonstrated that briny liquids could form “lids” of frozen material on top, which could insulate the underlying liquid, allowing it to flow further, much like lava in tubes on Earth.

Implications for Space Science:

This research adds to the growing compendium of work where laboratory experiments are used to mimic conditions on other worlds, helping scientists understand how long liquids can persist in environments where they would typically be expected to instantly evaporate or freeze. 

Michael J. Poston of the Southwest Research Institute, the study’s lead author, remarked, “This not only deepens our knowledge of Vesta but also aids in interpreting similar features on other planetary bodies, potentially including Mars and Europa.”

Looking Forward:

As space exploration continues to push the boundaries of our understanding, studies like these are crucial. They not only explain existing phenomena but also guide future missions and research. The Dawn mission, which concluded in 2018, has left a legacy of questions and discoveries, and this study is a testament to the ongoing scientific inquiry sparked by its findings.