[ad_1]
- NASA’s Juno mission discovered that Jupiter’s icy moon Europa produces 1,000 tons of oxygen every 24 hours.
- It’s enough to keep a million people breathing for a day, but it’s much smaller than previously thought.
- These new data may reduce the chances that Europa can support life in its vast underground ocean.
About 400 million kilometers away, floating in deep space, is a water world called Europa that produces 1,000 tons of oxygen every 24 hours. That’s enough oxygen to keep a million people alive for a day. NASA reported this week.
However, these new estimates, published in the peer-reviewed journal Nature Astronomy, are not intended to determine how many people could inhabit this moon of Jupiter. They are helping scientists determine whether Europa harbors life of its own or not.
“We think Europa is the most likely place to look for life beyond Earth today,” said Curt Niebur, NASA’s senior scientist for outer planet exploration who was not involved in the study.
If life forms exist on Europe, they could resemble microbes, or perhaps something more complex. according to nasa. But they would not be visible from the surface, which is a frozen desert.
They most likely exist in the Moon’s vast underground ocean, which can contain up to twice the amount of water as Earth.
While water is a key ingredient for life as we know it, it is not the only one. There is a long list of other chemicals that scientists are looking for, oxygen being one of them.
Now, NASA’s Juno spacecraft, currently flying around Jupiter and its moons, has made the most accurate estimate of Europa’s oxygen production to date. And it turns out to be much less than we thought.
The latest estimate of 1,000 tons of oxygen every 24 hours is more than 86 times lower than some previous estimates. And this new data may call into question the habitability of Europe.
How Europe produces oxygen
Oxygen production is very different on Europa than on Earth. While Earth gets its oxygen from photosynthesis, Europa’s is the result of its parent planet, Jupiter.
Jupiter emits powerful radiation that bathes Europa with high-energy particles. These particles then interact with frozen water ice (H2O) on the moon’s surface.
The interaction splits the H2O molecules into hydrogen and oxygen gas. But the big question is where that oxygen goes. Some of it may become trapped in the ice, some may escape into space, and some may travel to Europa’s underground ocean.
If enough oxygen reaches underground, that would mean Europa’s ocean has one of the critical ingredients for life as we know it. “But that’s a big question mark for us,” since oxygen can end up in many different places, Niebur said.
What NASA’s Juno mission has done is shed more light on the total amount of oxygen generated by Europa’s surface. However, it is still unclear how much, if any, leaks into the underground ocean.
Oxygen measurement in Europe
To measure how much oxygen Europa’s surface generates, scientists used the Jovian Auroral Distributions Experiment (JADE) instrument aboard Juno.
JADE was designed to measure charged particles in the auroral regions of Jupiter. But when Juno flew over Europa in September 2022, JADE successfully measured charged particles released from the moon’s atmosphere for the first time.
Using JADE data, scientists estimated the total amount of hydrogen gas (not oxygen) in Europa’s thin atmosphere. Since there is one oxygen atom for every two hydrogen atoms in a water molecule, scientists could use the hydrogen gas data to calculate the amount of oxygen generated at the surface.
“This has really refined and narrowed our understanding of how much oxygen is produced at the surface,” said the study’s lead author, Jamey Szalay, a space physics researcher at Princeton University.
“But we don’t know how much leaves the surface and how much reaches the ocean,” Szalay added. NASA’s next mission to Europa, Clipper, could bring us closer to answering that question.
A continuous search for the possibility of life.
NASA’s Europa Clipper mission is scheduled to launch in October 2024. Its primary goal is to determine whether Europa is habitable or not.
Clipper will be equipped with instruments that should help reveal Europa’s internal structure, such as its underground radar. With this tool, NASA scientists will look tens of kilometers beneath the crust to identify features that could help determine whether oxygen is reaching the subsurface ocean, Niebur told BI.
“Clipper is an incredibly exciting mission and has important scientific objectives that will likely revolutionize our understanding of the ice sheet, the subsurface ocean, and how they interact with each other,” Szalay said.
While finding out whether Europa’s subterranean ocean contains oxygen or not would improve our understanding of the moon’s habitability, it will not automatically confirm whether life exists or could exist on Europa.
“The amount of oxygen available on Europa is not a binary switch that is flipped to decide whether life could exist or not,” Niebur explained.
He noted that life existed on Earth for about 1.5 billion years without oxygen. If this could happen here, it could also happen on this distant moon.
As for the Juno mission, Szalay will continue working with the data he recovered during this flyby of Europe.
“Over the next few years, we’ll dig into this and learn everything we can,” he said.