Nasa announces more evidence for oceans on Jupiter's moon

NASA has announced some '"surprising evidence of activity" from one of Jupiter's largest moons on Monday, releasing new images captured from the Hubble Space Telescope.

The images provide more evidence that there may be oceans on Europa.

CGI of possible water plumes 'erupting' on Europa
CGI of possible water plumes 'erupting' on Europa Credit: NASA

However, despite fevered speculation on social media - Europa is considered to be one of the best places to find alien life in the Solar System and astrobiologists have theorised that organisms could survive in its oceans - Nasa quelled expectations, before the press conference:

“Astronomers will present results from a unique Europa observing campaign that resulted in surprising evidence of activity that may be related to the presence of a subsurface ocean on Europa,” the agency said.

Participants in the teleconference included Paul Hertz, director of NASA’s Astrophysics Division; William Sparks of the Space Telescope Science Institute in Baltimore; Britney Schmidt of the Georgia Institute of Technology; and Jennifer Wiseman, senior Hubble project scientist at NASA’s Goddard Space Flight Center.

Europa one of the largest of Jupiter’s 67 known moons. In late 2013 the Hubble telescope observed water vapor erupting from Europa, in what was hailed as a ‘tremendously exciting’ discovery.

Hubble finds additional evidence of water vapor plumes on Europa
Hubble finds additional evidence of water vapor plumes on Europa Credit: Caltech/NASA

Previous scientific findings had already pointed to the existence of an ocean located under Europa's icy crust, but it was thought teams in the future would have to drill through the thick later of ice before any signs of life would be detectable.

Jupiter's ice-covered moon, Europa, pictured by the Galileo spacecraft in 1997
Jupiter's ice-covered moon, Europa, pictured by the Galileo spacecraft in 1997 Credit: HO

Lorenz Roth of Southwest Research Institute in San Antonio said at the time that if the plumes of vapour were connected to the ocean beneath the crust they could start searching for life nearer the surface.

“This means that future investigations can directly investigate the chemical makeup of Europa's potentially habitable environment without drilling through layers of ice,” he said.

“And that is tremendously exciting."

 

                                                                                                    

Press conference is wrapping up

The press conference is drawing to a close.

In essence, Nasa are saying they are just providing more info for what we already had found.

How does this advance Lorenz Roth's work?

Answer:

We have upper limits and we have images in which we have evidence.

Roth has only ever seen anything once, and tried to follow it up.

We're not proposing a sequence, or any models.

What we are saying is that if they are real, they have to be intermittent.

It's significant because previously there has only been one piece of evidence that they exist.

"We would kill to have that much data"

The Nasa scientists say they have far more info on Enceladus - which we know has oceans.

"We would kill to have that much data on Europa," said one.

How much uncertainty was there before?  

Answer:

The statistical significance of these results is basically the same as the previous results.

In the formal sense the probable chance of this occurring is statistically low,

So in the formal sense we have a statistical projection.

It's more a subjective uncertainty than an objective uncertainty.

There may be things about the telescope we do not understand.

The intermittancy can be interpreted.

It's just a slight worry that we don't understand everything about a challenging wavelength we are working on.

Why are there not more instruments?

Answer:

We have nine instruments on the Europa fly-by mission.

So with that we can investigate.

 

Can the Juno Spacecraft help?

Answer:

We want to avoid contamination, so Juno is not slated to go anywhere near.

What are the biggest unknowns?

Question: What are the biggest unknowns?

Answer:

We need to understand their timing.

We need to search for this at close range, from the Europa fly-by mission.

Why has this taken so long?

Question: If there have been obvservations since 2014, why are they only being recorded now?

Answer:

We take the images in a time-tag mode. We needed to carefully analyse the motions of Europa and Jupiter together. And then we had to check them, that we got this right. It's a complicated process.

Subsequently we did observe two more transits and we have just started analysing the data, and will have the information for you when we have it.

Summing up the press conference

The scientists have concluded their presentation.

In essence, they believe that they are now closer to proving that Europa has oceans.

"Missions support each other"

Now we are hearing from Jennifer Wiseman, senior Hubble project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

"Hubble is the only telescope that we have right now able to study Jupiter and Europa in ultraviolet light."

She says they are working to detect the plumes.

"As mentioned before, previous evidence of plumes was found, but using it in a different way.

"We are thrilled about this findings because it was enabled by the heroic repair of the telescope in 2004.

"We are making special efforts now to use Hubble's unique ultraviolet capabilities."

"This is a great example of how Nasa's missions support each other."

Europa vs Enceladus

Britney Schmidt, assistant professor at the School of Earth and Atmospheric Sciences at Georgia Institute of Technology in Atlanta, is now speaking.

"Europa is about the size of the Earth's moon."

She is drawing comparisons with the moon Enceladus.

You can read more about Enceladus, which also has an ocean, here.

About Europa

Europa orbits Jupiter every three and a half days.

Europa is entirely locked to Jupiter.

From William Sparks:

"If plumes exist, this is an exciting finding as it would enable us to access it, without drilling through ice.

"We do not claim to have proven the existence of plumes, but rather contributed to evidence."

"Working at the limits"

More from William Sparks, astronomer with the Space Telescope Science Institute in Baltimore:

"We are really working at the limits of Hubble's unique capabilities."

He says that in 2013 a team found evidence of water - hydrogen and oxygen, in emissions.

 

Europa has liquid

Paul Hertz, director of the Astrophysics Division at NASA Headquarters in Washington, says Nasa plans to keep the Hubble telescope working for years to come.

William Sparks, astronomer with the Space Telescope Science Institute in Baltimore, says that:

Observations indicate a global, saline, liquid material engulfs Europa.

We may be able to explore this without having to drill through oceans of ice.

 

 

 

Nasa space telescope results

Paul Hertz, director of the Astrophysics Division at NASA Headquarters in Washington, is speaking now.

"Europa is of great interest.

"If we cannot fly a mission close, the next best thing is the Hubble telescope."

Nasa is now beginning a press conference on new results from the Hubble telescope

The press conference is beginning.

"Despite what some media is reporting, this new research has nothing to do with finding life on Europa."

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