Water plumes over Europa Options

[stevesliva]

vertical ice-pipes

You mean like penitentes? Wikipedia calls them "almost a black body"
https://en.wikipedia.org/wiki/Penitente_(snow_formation)

[HSchirmer]

You mean like penitentes? Wikipedia calls them "almost a black body"

Well, conceptually similar -
ice structures grow due to "phase change" as water forms ice and accumulates in areas with higher heat loss.
But penitenties are sublimation and radiative heat loss to the sky, while ice pipes are snowpack melting and conductive heat loss to the ground.

So, practically, think "upside down penitentes".

Found it- red aeolian dust changes how snowpacks melt-

the variation in ice column morphology between red and clean snow gives insight into how dust deposition events may affect the energy balance, subsequent melt, and meltwater flowpaths in snow covered areas

The movement of liquid water through the snowpack in “red” snow thus appears to be more uniform, decreasing the size of preferential flowpaths that give rise to ice columns.

[rogelio]

Well, conceptually similar -
ice structures grow due to "phase change" as water forms ice and accumulates in areas with higher heat loss.
But penitenties are sublimation and radiative heat loss to the sky, while ice pipes are snowpack melting and conductive heat loss to the ground.

So, practically, think "upside down penitentes".

Found it- red aeolian dust changes how snowpacks melt-

the variation in ice column morphology between red and clean snow gives insight into how dust deposition events may affect the energy balance, subsequent melt, and meltwater flowpaths in snow covered areas

The movement of liquid water through the snowpack in “red” snow thus appears to be more uniform, decreasing the size of preferential flowpaths that give rise to ice columns.

Penitentes up to 15 m high, spaced 7.5 m apart at the equator? Challenging for a lander...

https://www.nature.com/articles/s41561-018-0235-0

[stevesliva]

First bright stellar occultation for Europa:
http://sci.esa.int/gaia/61491-astronomers-...thanks-to-gaia/

Relevant to this thread because the Hubble data was, I think, derived from Europa occulting Jupiter.

Surprised it's the first!

[Jaro_in_Montreal]

Today's announcement:

https://www.nasa.gov/feature/goddard/2019/n...vapor-on-europa

[JRehling]

This is an exciting result. The intermittent nature of the plumes may create a challenge for Europa Clipper to sample them without some flexibility to alter the mission in response to unpredictable events.