We’ve talked about Europa and the search for
extraterrestrial life on the ice giant here at To Infinity and…In Theory
before. We’ve delved into life’s ability to thrive in some of the most hostile environments
imaginable. (Missed those entries? Catch up on the four part series “Livin’
Life to the Extremophile” by following these links. Part 1: Vostok. Part 2: Europa. Part 3: Chemosynthesis.
Part 4: Biodiversity.)
But when we talked about all that stuff
before we didn’t talk very much about the most important thing. How exactly are
we going to get underneath the huge sheet of ice surrounding Europa to the
ocean of frozen mystery beneath? Scientists at several different agencies, from
the big ones like NASA and the ESA to other firms like Stone Aerospace and
Honeybee Robotics, are coming together to help answer that question.
The answer seems to lie in a multi-stage plan
that will play out over the course of a few decades. Further testing still
needs to be done to decide what will be the best approach for drilling into the
ice for starters. Then the funding has to be raised in order to launch a
mission of this scale. Luckily, researchers think they have an answer to that
as well.
Today we’re going to talk about Jupiter and
her moons, a program called JUICE, a payload delivery system called The
Penetrator, cryobots, and a mission to Europa just to listen to the ice.
But first, a quick recap on why Europa is so
promising in the search for life.
Sometimes You Just
Have To Vent
For the longest time scientists purported
that life could not exist at the depths of the ocean. The pressure was too
high, it would crush anything organic. The light didn’t reach, nothing could
possibly see to hunt and forage. Above all it would be far too cold. Then a
mission to the outskirts of the Marianas Trench changed everyone’s tune. Not
only was life discovered at the deepest depths at that time reached, but it was
thriving.
Now we know that life is even capable of
existing around some of the most hostile environments imaginable by using a
process called Chemosynthesis. These hostile environments I’m talking about are
the hydrothermal vents at the bottom of the ocean. Think of it like an
underwater volcano.
As the ocean floor shifts due to tectonic
activity from the way gravity affects our planet as it whirls through space, it
causes buildups of pressure. This internal pressure has to be released somehow,
so it vents it out to the ocean floor. Amongst this debris are little organic
bits. Not stuff you and I like, but the kind of stuff microorganisms flourish
on.
The same kind of thing is happening on
Europa. It’s believed to have a rocky mantle and a molten iron core just like
us. As it orbits around Jupiter, the stress from the gas giant’s gravitational
force causes geothermal activity within the core. Just like our planet it has
to be vented, hence the proposal for hydrothermal vents.
Only the surface is thought to be ice, the
thickest ice in our solar system, but underneath that is believed to be a
liquid ocean. If scientists are right the hydrothermal activity is what would
make this possible, heating the water just enough to keep it from freezing near
the mantle. How can they guess this from a few flybys and satellite snapshots?
The surface of Europa’s ice sheet is heavily
scarred, and most of it isn’t from collisions with interstellar objects. Like Lake
Vostok, a pocket lake within a sheet of ice in Antarctica, Europa is believed
to be dotted with miniature bodies of water. The reason is because of the
pattern of the scarring, there is no uniform structure to it.
It’s possible that as the moon orbits Jupiter
the stress causes the ice to crack, but it wouldn’t be quite so varied and so
jagged. When hydrothermal activity increases on the ice it may briefly unthaw
some of the ice above the pocket lake (not entirely) and shift the ice around,
causing the terrain patterns.
So now that we know what’s probably happening
underneath the ice, what’s the plan for getting us to it? I’m going to ask you
to try to keep your mind out of the gutter as we move on to our next section…
The Penetrator:
Between the Ice Sheets
Europa had better prepare its Uranus for
scientist Sanjay Vijendran’s payload delivery system because it looks like
whatever method the mission chooses to drill into the planet “The Penetrator”
is what’s going to be getting it there. It’s already been “drilled” through its
paces, and is officially marked as ready for space travel. It’s fairly light
given what it does, meaning an orbiting craft could launch several at a time,
and it’s extremely durable.
So what is it and how does it work?
During testing the Penetrator was aimed at a
10 ton block of ice in order to simulate the effects of what it will be like to
land (or crash really) on the surface of Europa. Weighing 44 pounds, it hit the
block at 760 MPH showing a peak deceleration of 24-25,000g. For a point of
reference, an ejecting fighter pilot experiences 14gs and typical soft-landing
spacecraft experience 30-40gs.
What’s even more incredible is it was fully
loaded with instruments and everything was just fine. All that happened was a
little cosmetic damage, a few scratches in the paint. Being that it’s capable
of burrowing up to 3m into the surface without the use of a drill, this could
be the most useful tool in planetary exploration to date. It could deliver a
vast array of scientific equipment for analysis of various factors. From
seismometers to chemical labs.
The Penetrator is split into two different
sections, the warm bay and the cold bay. The cold bay is for taking in samples
and the warm bay houses instruments and keeps them from being damaged by the
extreme temperatures on Europa (minus 200 degrees Celsius).
Its designer, Vijendran, has made note of its
advantages over soft landers. Where they have to slow down, this can hit at
full force, so all the space wasted from expensive instrumentation meant to
decelerate a craft can be utilized by other items.
And just what might those other things be?
Let’s take a look at some of the other toys possibly going along for the ride
to Europa.
Lasers,
Auto-Gophers, And Cryobots, Oh My!
So now that we know how they intend to get
onto the surface and drop off the equipment, what exactly are they bringing?
And not just that, what exactly is this equipment going to do and how does it
work? That’s a very good question and I’m so glad you asked it. The answer
however is sort of difficult because as of the time of this writing, even the
scientists aren’t sure what to pack in their lunchbox yet.
First and foremost they’re going to need
something to drill into the ice. Secondly they’re going to need something to
obtain and analyze samples. Lastly the equipment needs to be extremely durable
and able to withstand the tremendously frigid temperatures.
Two scientists named Victoria Siegel and Kris
Zacny have two very separate approaches to this same problem.
The Cryobot
According to Siegel’s team at Stone Aerospace
the ocean is where it’s at, “That’s where the big stuff is going to be
happening,” she says. But in order to get down to that “big stuff” we have to
be able to drill through 10 km of ice. (That’s a little over 6 miles.) There is
nowhere on Earth with a sheet of ice 6 miles thick. The Antarctic Ice Sheet is
the closest we have at 2.6, but we’re still talking about something over double
that. And it’s an exponentially colder and harsher environment trillions of
miles away.
Not to mention drilling creates problems.
There’s a lot of moving parts, in order to go deeper extensions need to be
added, and if something breaks it’s not like a maintenance crew can just catch
an interstellar taxi to Europa to fix it. The VALKYRIE cryobots hope to solve
all of those problems and give the team just what they’re shooting for.
They have been working on a device since 2011
that is capable of using meltwater (water sucked up through the jets and
heated) to bore its way through the ice. Once it reaches the ocean it will
launch a small submarine from its belly to get a bird’s eye view of the world
beneath the ice and to collect water samples to scan for signs of life.
Listen to how ScienceNews.org describes the
working of the cryobot.
“The cryobot, a tube
about as long as a compact car, holds wires coiled within a sleek aluminum frame
and five jets arranged in a domed head. By heating aluminum blocks within the
head, the cryobot can melt ice, and then suck in the water and shoot out hot
streams. To thaw the ultracold ice of Europa, the bot will need to carry some
sort of onboard nuclear reactor. Siegel and colleagues are testing their device
on Earth using laser light pumped down a fiber optics wire connected to the
machine.”
As of now the cryobot has moved into Phase-II
of its development and the underwater submersible, being developed by NASA are
solid candidates for the mission to Europa. The only thing (like most ambitious
missions) that could possibly hold them back is funding. Launching a piece of
equipment like that is costly and time will tell if the government is willing to
shell out the funds necessary to give Stone Aerospace the chance to prowl the
depths of Jupiter’s moon, and the go-ahead to launch a nuclear device to the
surface of a foreign and pristine world.
The Auto-Gopher
The Auto-Gopher is a wire-line rotary hammer
drill. In other words, it smashes its way through the ground as it digs into
it. Kris Zacny of the company Honeybee Robotics believes that this is the way
to go. It’s cheaper to use a drill then a robot, not to mention this will
require a significant amount less power to operate. So how does it all work?
“It’s like a fishing rod,” Zacny says, “and
at the end of the fishing line, you have a drill.” I suppose that’s an apt
description if you’re used to fishing with explosives. (Metaphorically
speaking) The teeth that jut out on the end of the drill are made of tungsten
carbide and to get it through the particularly rough spots in the ice they gave
it the ability to “thump” its way through by adding in a percussive system.
It only draws about 350 watts of power all in
all. That’s less than your microwave uses. The whole thing is attached to a
wire and pulley system so that sections don’t need to be added or removed. And
now they have funding for an even better drill. From the same ScienceNews.org
article check out this excerpt.
“Now the team is
working on a new and improved drill, the AMNH Deep Drill, named after its
funding source, the American Museum of Natural History. This drill will shuttle
rock or ice cuttings to a container inside the tube instead of creating cores
that have to be pulled from the borehole. And researchers plan to pack
electronics and equipment, such as a microscope and sensors, inside the tube.”
This method has several advantages. It means
every foot that the device goes down will be analyzed for scientific record and
the Kevlar coated wire is strong and avoids using bulky extensions that would
be difficult to add and remove. They’re also doing research into carbon
nano-tubes (so did we! “Nano-Tech:Big Problems, Small Answers”) in order to make the device even more
lightweight, making the Auto-Gopher just as, if not more, appealing to
potential backers.
In my personal opinion they should combine
the underwater submersible with the drill and go for broke. But what do I know?
I do know that this is all expensive, and while the president wants to give
funding to space programs, there isn’t a whole lot of money to spare, (what
with the bankers needing bailouts for gold Cadillac’s, Rolex’s, and private jet
fuel.) So what’s the plan?
Budget “Clipper”
NASA’s got a plan for Europa exploration as
well. It’s called Clipper. It’s a highly advanced, extremely durable satellite
that will optimally perform 45 flybys of the ice moon at varying altitudes. It
will take highly advanced pictures of the surface, scan the exact thickness of
the ice (right now the thickness is just an educated guess), document radiation
levels in the atmosphere and record exact temperatures on the entirety of
Europa, there are a host of other possibilities this device brings to the table
as well.
The problem is the $2.2 billion price tag.
The Obama administration is willing to work with NASA, but only to the extent
of $1 billion. Dr. Britney Schmidt who is spear-heading Clipper is thrilled the
President has brought Space Exploration to the party finally but the budget is
less than ideal.
Another scientist however, by the name of
Christopher McKay thinks that that will be plenty enough. If the whole goal is
to examine the surface of Europa and scan under the ice then he has just the
plan for them. He intends to land a camera and a microphone on the surface to “listen”
to the ice.
No that isn’t a joke. As the ice moves around
scientists will be able to tell exactly what’s going on beneath the surface. How
they are able to do this eludes me but if there’s a person who can translate it
then I can get behind it. While I doubt Europa will be appearing on the next
Santana album for a live duet with the guitar playing legend, this “ice noise”
could bring us one step closer to missions like Spiegel’s, Schmidt’s, and Zacny’s.
This kind of exploration builds confidence
and public interest, which is exactly what missions like Clipper and the
Auto-Gopher are hinging on now. But while America is scrambling for the scraps,
the ESA grabbed a V-8 and got juiced up for a little mission of their own.
Europe JUICE-in’ Up
For Europa
While NASA is tuned
into the Europa station, the European Space Agency is looking at the whole
picture. All three Galilean moons are thought to contain liquid water somewhere
beneath the surface. If we’re going to be in the neighborhood, why not see all
the sights? The ESA is planning to send a probe called JUICE (JUpiter ICy moons Explorer) into
orbit around Callisto, Europa, and Ganymede.
The goal is to
study the composition of water beneath, survey the topographical features of
the planets more thoroughly, investigate their potentiality to contain life as
we think we know it, and many, many other awesome plans. There’s something even
better, this is already in the works.
The time frame to
deliver JUICE to the Jovian system is 2030 with a launch from Earth taking
place as early as 2022. The prospect of this is exciting and they have plenty
of time to make revisions and add other instrumentation. Russia is developing
most of the components and say what you will about their foreign policy, they
make some really good stuff.
With all the
options open to us above and many others that could become potential candidates
in the future we will certainly be seeing some kind of landing within the next
twenty to forty years. Time will tell. Speaking of time, here at TI&IT we
like to delve into the history of things as well as the science, after all,
what are we without our past?
The question really
isn’t who discovered these moons, we attribute that to astronomer Galileo, but
what some may not know is while he is credited, someone may have discovered
them first. Let’s take a look at the remarkable past of Jupiter’s biggest
satellites.
Galileo and the
Medicean Planets
The photo above
that looks like the scribbling of a madman in a ward is actually the
handwriting of the brilliant Galileo Galilei himself. He discovered the planets
sometime around 1609-1610 while he was making improvements to his telescope. He
originally named them the Medicean Stars in honor of the Medici family, but
later it was discovered they were moons.
And it wasn’t much
later either. In fact, it may have been earlier. A man named Simon Marius, a
German astronomer, had made observations a few days prior of the same nature.
In 1614 he published his paper “Mundus Lovialis”
detailing his discovery of Jupiter’s moons. You can imagine this led to some
heated debates between him and Galileo.
In the end it is irrelevant
who discovered it first, Marius ultimately won out the name-calling as the
celestial bodies Io, Ganymede, Europa, and Callisto were the names he selected.
And thankfully history was kind enough to remember him for that. Remnants of
his work are scarce but he’s credited as “a clever observer” which is probably
not the most sought after title in the scientific community.
But then again,
what are all of us now?
Jupiter’s moons are
named after Greek mythology. To be exact they are named after the lovers of
Zeus. For the sake of the length of this article already we won’t go into too
much about this now, but I’m sure in the future we will be talking about Europa
once again.
Europa’s Cold Future
While we probably won’t find space penguins
orbiting around the moons of Jupiter or Saturn we may find some sort of life.
That is if we can get the funding to get off the ground and get there. From
cryobots to satellites there are a number of possibilities for exploring these
intriguing heavenly worlds.
But as usual, money will hold scientific
progress back. While that is depressing I hope you enjoyed this article on the
future of Europa. Please share this around on Facebook and Twitter, I would be
eternally grateful. Thank you all for reading, and enjoy this comical pun.
-Ryan
Sanders
If you want to know more about any of
the topics discussed above feel free to follow any of the links below! As
always, thanks for reading and Happy Learning!
