Hubble discovers water vapor venting from Jupiter's moon Europa

Dec 12, 2013
This artist's impression shows Jupiter and its moon Europa using actual Jupiter and Europa images in visible light. The Hubble ultraviolet images showing the faint emission from the water vapour plumes have been superimposed, respecting the size but not the brightness of the plumes. Credit: NASA, ESA, and M. Kornmesser. Science Credit: NASA, ESA, L. Roth (Southwest Research Institute and University of Cologne, Germany), J. Saur (University of Cologne, Germany), K. Retherford (Southwest Research Institute), D. Strobel and P. Feldman (Johns Hopkins University), M. McGrath (Marshall Space Flight Center), and F. Nimmo (University of California, Santa Cruz)

The NASA/ESA Hubble Space Telescope has discovered water vapour erupting from the frigid surface of Jupiter's moon Europa, in one or more localised plumes near its south pole.

Europa is already thought to harbour a liquid ocean beneath its icy crust, making the moon one of the main targets in the search for habitable worlds away from Earth. This new finding is the first observational evidence of being ejected off the moon's surface.

"The discovery that vapour is ejected near the south pole strengthens Europa's position as the top candidate for potential habitability," said lead author Lorenz Roth of the Southwest Research Institute in San Antonio, Texas. "However, we do not know yet if these plumes are connected to subsurface liquid water or not." The Hubble findings will be published in the 12 December online issue of Science Express, and are being reported today at the meeting of the American Geophysical Union in San Francisco, California, USA.

The Hubble discovery makes Europa only the second moon in the Solar System known to have water vapour plumes. In 2005, plumes of water vapour and dust were detected by NASA's Cassini orbiter spewing off the surface of the Saturnian moon Enceladus.

The Europa plumes were discovered by Hubble observations in December 2012. The Space Telescope Imaging Spectrograph (STIS) detected faint ultraviolet light from an aurora at the moon's south pole. This aurora is driven by Jupiter's intense magnetic field, which causes particles to reach such high speeds that they can split the water molecules in the plume when they hit them, resulting in oxygen and hydrogen ions which leave their telltale imprint in the colours of the aurora.

This graphic shows the location of water vapor detected over Europa's south pole that provides the first strong evidence of water plumes erupting off Europa's surface, in observations taken by NASA's Hubble Space Telescope in December 2012. Hubble didn't photograph plumes, but spectroscopically detected auroral emissions from oxygen and hydrogen. The aurora is powered by Jupiter's magnetic field. This is only the second moon in the solar system found ejecting water vapor from the frigid surface. The image of Europa is derived from a global surface map generated from combined NASA Voyager and Galileo space probe observations. Credit: NASA, ESA, and L. Roth (Southwest Research Institute and University of Cologne, Germany)

So far, only water vapour has been detected—unlike the plumes on Enceladus, which also contain ice and dust particles.

"We pushed Hubble to its limits to see this very faint emission," said co-lead author and principal investigator of the Hubble observing campaign Joachim Saur of the University of Cologne, Germany. "Only after a particular camera on the Hubble Space Telescope had been repaired on the last servicing mission by the Space Shuttle did we gain the sensitivity to really search for these plumes."

Roth suggests long cracks on Europa's surface, known as linea, might be venting water vapour into space. Similar fissures have been photographed near Enceladus's by the Cassini spacecraft. It is unknown how deep inside Europa's crust the source of the water may be. Roth asks, "Do the vents extend down to a or are the ejecta simply from warmed ice caused by friction stresses near the surface?"

Also like Enceladus, the Hubble team found that the intensity of the plumes varies with Europa's orbital position. Active geysers have only been seen when the moon is furthest from Jupiter. But the researchers could not detect any sign of venting when Europa is closer to Jupiter.

One explanation is that the long fractures in the ice crust experience more stress as gravitational tidal forces push and pull on the moon and so open vents at larger distances from Jupiter. The vents are narrowed or closed when at closest approach to the gas giant planet. Team member Kurt Retherford, also of the Southwest Research Institute, points out that "the plume variability supports a key prediction that we should see this kind of tidal effect if there is a subsurface ocean on Europa".

Future space probe missions to Europa could confirm that the exact locations and sizes of vents and determine whether they connect to liquid subsurface reservoirs. It is important news for missions such as ESA's JUpiter ICy moons Explorer, a mission planned for launch in 2022, and which aims to explore both Jupiter and three of its largest moons: Ganymede, Callisto, and Europa.

Explore further: New computer model may explain moon Europa's chaotic terrain

More information: Science paper "Transient Water Vapor at Europa's South Pole": www.spacetelescope.org/static/… papers/heic1322a.pdf

Related Stories

Clay-like minerals found on icy crust of moon Europa

Dec 11, 2013

(Phys.org) —A new analysis of data from NASA's Galileo mission has revealed clay-type minerals at the surface of Jupiter's icy moon Europa that appear to have been delivered by a spectacular collision with ...

Liquid water near Europa's surface a rarity

Sep 25, 2012

(Phys.org)—Europa, the enigmatic moon of Jupiter, is believed to be home to a subsurface ocean of liquid water. However, future missions to explore Europa's ocean may need to dig deep. Research suggests ...

Mapping the chemistry needed for life at Europa

Apr 05, 2013

(Phys.org) —A new paper led by a NASA researcher shows that hydrogen peroxide is abundant across much of the surface of Jupiter's moon Europa. The authors argue that if the peroxide on the surface of Europa ...

Recommended for you

Hinode satellite captures X-ray footage of solar eclipse

5 hours ago

The moon passed between the Earth and the sun on Thursday, Oct. 23. While avid stargazers in North America looked up to watch the spectacle, the best vantage point was several hundred miles above the North ...

Asteroid 2014 SC324 zips by Earth Friday afternoon

15 hours ago

What a roller coaster week it's been. If partial eclipses and giant sunspots aren't your thing, how about a close flyby of an Earth-approaching asteroid?  2014 SC324 was discovered on September 30 this ...

User comments : 14

Adjust slider to filter visible comments by rank

Display comments: newest first

cantdrive85
1 / 5 (11) Dec 12, 2013
More evidence of EDM which is misrepresented as water plumes.
Torbjorn_Larsson_OM
4.6 / 5 (10) Dec 12, 2013
More evidence that interesting science like astrobiology draws the dark side of humanity, such as antiscience trolling. :-/
animah
4.8 / 5 (5) Dec 12, 2013
EDM??? The reporting journalist's weak wording notwithstanding, that plume was not photographed by a camera but by a spectrograph. AFAIK the confusion is not even physically possible with that instrument.
antialias_physorg
5 / 5 (7) Dec 12, 2013
Dammit..why are we sending one probe after another to Mars when something like this is beckoning?
I realize Mars is probably an easier target than Europa, but we really need to send something there to have a look.
DeliriousNeuron
1 / 5 (4) Dec 12, 2013
And so Jupiter's faint ring system is created. Saturn, Uranus and Neptune likely the same procees.
nkalanaga
2.8 / 5 (5) Dec 12, 2013
antialias_physorg: I agree that Europa is a very interesting object, and should be a prime target for exploration. Two reason I can see besides the energy (delta-V) needed to get there:

1: Jupiter's radiation belts make shielding both mandatory and difficult. The extra mass is a relatively minor problem for an orbiter, but could be a deal-breaker for a lander.

2: We have a fairly good idea of surface conditions, and thus some idea of likely biologies, on Mars. We can at least try to sterilize the landers. We have no idea what might be living on or in Europa, and anything that can survive the surface radiation levels might well be unkillable without destroying the spacecraft itself. Until we can be reasonably sure that we won't contaminate the surface, caution seems to be warranted.

A flyby though these geysers could return material for study, possibly cheaper than a well-equipped lander.
goracle
4 / 5 (4) Dec 13, 2013
Dammit..why are we sending one probe after another to Mars when something like this is beckoning?
I realize Mars is probably an easier target than Europa, but we really need to send something there to have a look.


ALL THESE WORLDS ARE YOURS -- EXCEPT EUROPA
EnricM
3.9 / 5 (7) Dec 13, 2013
More evidence of EDM which is misrepresented as water plumes.


Electronic Dance Music or Event Driven Marketing ?
EnricM
2 / 5 (3) Dec 13, 2013
Dammit..why are we sending one probe after another to Mars when something like this is beckoning?
I realize Mars is probably an easier target than Europa, but we really need to send something there to have a look.


With drills, and a sonar!!! And even better if it's a rover, well it would have to be atomic, but hell, I don't care! Send it !!!!
GSwift7
4 / 5 (1) Dec 13, 2013
Dammit..why are we sending one probe after another to Mars when something like this is beckoning?


There is synergy between concurrent missions around any given place. Orbiters can cross reference observations between different instruments for callibration, for example, or an orbiter can photograph the location of a rover and its surroundings and act as a communication relay, or predict dust storms. These orbiters and rovers have a limited lifespan though, so it makes sense to get as much work out of them as you can, before you lose them.

Besides, there are lessons to be learned from Mars that might apply to other bodies that are smaller and colder than Earth. For example, we now know (thanks to Curiosity) that despite Mars' lack of magnetic field and thin atmosphere, solar radiation isn't too dangerous there. We do need to know these things, and Mars is the easiest place to visit after the moon. Why not do Mars first, then go farther later?
cantdrive85
1 / 5 (4) Dec 13, 2013
More evidence of EDM which is misrepresented as water plumes.


Electronic Dance Music or Event Driven Marketing ?

Electric discharge machining, you must be new here.
GSwift7
2.4 / 5 (5) Dec 13, 2013
Hey, look at that!! If you move the slider on the comment filter a little to the right, you don't have to see any of cantdrive's comments any more.

Matter of fact, about half the comments on the page go away. Cool.

Oh, and the site doesn't display your ranking history any more, so that should take all the fun out of it for the people with sock puppet accounts, rating whores and 1-bots. I like the changes they made to the site. What a nice improvement.
Gawad
5 / 5 (2) Dec 13, 2013
Oh, and the site doesn't display your ranking history any more, so that should take all the fun out of it for the people with sock puppet accounts, rating whores and 1-bots. I like the changes they made to the site. What a nice improvement.


Unfortunately, it still does. You have to click All>> beside recent comments to get to that page and it's still there.
Zephir_fan
Dec 13, 2013
This comment has been removed by a moderator.
cantdrive85
1 / 5 (4) Dec 13, 2013
Oh, and the site doesn't display your ranking history any more, so that should take all the fun out of it for the people with sock puppet accounts, rating whores and 1-bots. I like the changes they made to the site. What a nice improvement.


Skippy if you had one of those really smart computers like the Ira has you would know that just is not true.

https://sciencex....n/?v=act


Don't blame the tool the tools use.
Zephir_fan
Dec 13, 2013
This comment has been removed by a moderator.