NASA’s Cassini spacecraft discovered that Saturn’s moon Enceladus is spraying water into space from fissures at its south pole. This plume of ice and vapor is sourced from a subsurface ocean that contains most of the ingredients needed for life, as well as signs of underwater heat sources, making Enceladus a top target for future missions searching for life beyond Earth.

One of Cassini’s instruments showed that the makeup of this icy ocean spray can be studied by analyzing how chemicals in the ice break apart when they hit the spacecraft at high speed. However, experiments on Earth haven't been able to precisely replicate and study this process yet. To solve this, we have developed a new laboratory method that mimics the conditions of flying through and sampling Enceladus’s plume at high speed. This method works even with salt-rich samples, which are similar to what’s expected from Enceladus’s ocean. Our results suggest that both the salt level and the speed of the spacecraft can affect the results, possibly making it harder to tell what the ice is made of. Analyzing data from future missions will need to take this into account to ensure accuracy in determining ice grain composition.