Europa Clipper Mission: Finding Alien life in the oceans of Europa
What is Humanity’s best bet to find life outside Earth?
If you had asked this question in the 80s to a NASA’s Viking mission scientist,
he would probably say, “We’ll know in a couple of years for sure”. Today nearly half a century
after NASA’s Viking mission to mars, hopes of finding life on mars have slowly faded away. In
these last 50 years scientists have come to grips with how hard it is to find life outside of earth.
We could detect biosignatures from exoplanets and infer about the existence of life on that planet,
but we can never directly observe them. At Least with the current technology that we have.
Therefore most of the questions about extraterrestrial life have the chance to
go unanswered. But if we are able to detect life in our own backyard, that is, our solar system, it
would be one of the most intriguing discoveries. Mars, being closest to Earth, had given a lot of
hope to scientists which has slowly faded away. Though, In the last few decades a new possibility
has come to light and a very convincing one- Jupiter’s moon, Europa. Europa might be our
best bet to find life outside of Earth. But how do we plan to learn more about this strange moon?
Why is it so intriguing and important to us? We’ll talk about that and more.
Life has formed and evolved on Earth in even the harshest of conditions.
Today we know life can form and thrive in the most extreme environments on Earth.
And Europa’s environment might not be so extreme. Life on earth requires three things: a source of
energy, a liquid solvent like water, and elements that can form complex molecules and organisms.
Jupiter’s moon Europa might have all these three things.
Today Europa is believed to be our best bet to find extraterrestrial life by many scientists.
In 2024, NASA’s spacecraft, Europa Clipper will be launched aboard SpaceX’s Falcon Heavy rocket, on a
mission to determine whether Europa can support life. Seven years after the launch, Clipper
is scheduled to make its first encounter with Europa on March 7, 2031. This will be the first
ever mission by humanity to explore an oceanic world besides Earth. The Clipper spacecraft will
perform 50 close flybys of Europa from its lengthy orbit around Jupiter. Europa Clipper will help us
comprehend the potential for life on potential ocean worlds in our solar system and beyond
by evaluating whether Europa has the three basic requirements for life to exist- a source of
energy, a liquid solvent like water, and elements that can form complex molecules and organisms.
Europa is slightly smaller than earth’s moon and is covered with an ice shell roughly 12
miles thick. Under this ice shell, lies a liquid saltwater ocean upto 100 miles deep,
which is twice the amount of water than on Earth’s oceans. No sunlight reaches
Europa’s ocean floor but vents on the ocean floor may release heat from the moon’s core.
Similar vents in the darkest, deepest parts of Earth’s oceans can be found teeming with life- no
sunlight required. Similar vents can be discovered thriving with life in the deepest, darkest areas
of the Earth's seas - no sunshine necessary. Though Europa Clipper cannot directly detect life,
it is designed to answer very specific questions about the plausibility of life on Europa.
NASA always designs missions with big questions in mind, but they can only answer smaller
specific questions. As a result, scientists are investigating various characteristics of Europa
and doing simulations to fine-tune the questions that the expedition will need to ask. The
spacecraft will enter Jupiter’s orbit and perform approximately 50 close flybys. It is outfitted
with highly sophisticated instruments– a mass spectrometer to investigate the contents of the
surface ice, a magnetometer, radar to investigate the structures under the surface, and many more.
But there might be a question bugging you! Being a distant frozen world from the sun,
How could life survive and evolve on Europa? Well, beneath the icy shell of Europa is briny water,
mixed with minerals that are partially frozen but are also liquid enough to have convection. Below
the saltwater lies a vast liquid ocean with more than double the amount of water found in Earth's
seas. Because of tidal pressures from its giant parent, Jupiter, Europa is not frozen solid (as
it would be given its size and distance from the sun). These tidal pressures alter Europa, creating
friction and heating. Scientists also predict the presence of volcanoes on the ocean floor which
might be feeding the oceans with rich minerals. So if you have Heat, lots of minerals and liquid
water, you have the three basic ingredients for life. Even though sunlight is still missing,
we have seen chemosynthetic organisms on earth that live near the ocean floor vents
and feed off the rich minerals. They can feed off the sugar to get energy.
So it might be that chemosynthesis is going on in the oceans of Europa. But you might notice another
problem here– the need for oxygen. The oceans on Earth are oxygen-rich due to photosynthesis,
which utilizes sunlight to convert carbon dioxide and water into sugar and oxygen. There should be
no photosynthesis taking on beneath Europa's ice, which can mean no oxygen and hence no
life. So does that mean our last and best hope for finding extraterrestrial life is a disappointment?
Well, not really. There is still hope for life on Europa. The frozen moon has oxygen at its
surface. When sunlight and charged particles from Jupiter impact the moon's surface, oxygen
is produced. But there's a problem: Europa's vast ice cover acts as a barrier between the ocean
and oxygen. Because Europa's surface is frozen solid, any life must exist in its huge ocean.
How does oxygen go from the surface to the ocean? According to new research, pools of saltwater
in Europa’s icy shell could be transporting oxygen from the surface to the ocean floors.
The process begins with charged radiation particles striking Europa's surface,
breaking down the water ice into hydrogen and oxygen. Because hydrogen is so light,
it floats away. The oxygen, on the other hand, primarily remains on Europa's surface, with some
dissolving into the thin atmosphere. This surface oxygen dissolves into Europa's surface ice,
generating small oxygen bubbles. The simulation is concerned with the fate of these little bubbles;
will they sink into the ocean? In certain regions of Europa, also known as “chaos regions”,
because of their complex surface features, the icy shell is thinnest. Chaos terrain makes upro
25 percent of Europa’s frozen surface. Chaos terrain is made up of jumbled hills,
fissures, faults, and flats. The specific causes of chaotic terrain are unknown,
however they are most likely connected to uneven subsurface heating and melting.
This curiously lovely feature is highlighted in some of Europa's most memorable photos. The ice
on Europa's surface is 15-25 km thick, but it may be just 3 km thick in the chaotic zones,
which encompass 25% of the moon's surface. Warmer briny water may be pushing up in certain areas,
weakening the ice and bursting through to the surface on occasion.
The simulation reveals that in some regions, there may be porosity waves (similar to a human
wave in a stadium, but with porous pieces of ice), and that these porosity waves may carry
oxygen bubbles down through the saline frozen ice all the way to the deep ocean. This process can
take thousands of years, but once it's started, it would provide a constant stream of oxygen from
the surface to the ocean in substantial amounts — enough to maintain a life-supporting environment.
The connection between chaotic terrain and oxygen transport is not entirely established. However,
scientists believe that convective upwellings induced by tidal warmth partially melt the ice,
resulting in the surface's tangled chaotic topography. For the oxygen-rich brine to
drain into the ocean, the ice beneath the brine must be molten or partially molten. According to
the findings, around 86 percent of the oxygen taken up at Europa's surface makes its way to
the ocean. That proportion might have altered dramatically during the moon's history. However,
the researchers' model produces an oxygen-rich ocean that is quite similar to Earth's. Is there
something living beneath the ice? We know that Europa possesses helpful molecules on its surface,
such as oxygen, but do such compounds make it down into the ocean below, where life may utilize them?
If true, this is an interesting prospect that might address Europa's "dark life" dilemma.
And this is where the importance of Clipper mision comes into play. Outfitted with this new
hypothesis, the highly sophisticated instruments on the spacecraft could investigate the
credibility of this process and hypothesis. It may detect oxygen concentrations on Europa's surface,
and the radar could record what's going on under the surface. Clipper is meant to
examine the subject of life on Europa, however it can only study proxy questions. The devices
are not intended to discover life directly, but rather to answer scientific questions about how
likely life is, and studies like this one are critical to the study that Clipper will do.
The Clipper mission is the first dedicated to Europa. We believe we know a lot about
Europa but haven't been able to confirm it. On top of this, the Clipper mission
will also lay the foundation for future Europa missions, especially a lander mission on Europa,
which can directly detect life. The Clipper is intended to achieve three major goals:
Examine the ocean's composition to see whether it has the elements required to support life.
Investigate the moon's geology to learn how the surface,
particularly the chaotic landscape, developed. Determine the thickness of the ice shell and
whether or not there is liquid water within and underneath it. They will also influence
how the ocean interacts with the surface: Is there anything in the ocean that rises to the
surface through the shell? Is there any stuff from the surface that makes its way into the ocean?
Like the famous saying from Jurassic park, “Life finds a way”: If there is energy and other basic
ingredients for life in the oceans of Europa, life will likely find a way. So what do you think about
the possibility of alien life in the oceans of Europa? How will it change our understanding
of science? Let us know your thoughts in the comment section. We would love to have
a discussion on these questions. Also make sure to like the video and subscribe to the channel.
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