An artist's rendering of the Europa mission's spacecraft. Main Image: NASA/JPL-Caltech Banner Image: NASA/JPL-Caltech
An artist's rendering of the Europa mission's spacecraft. Main Image: NASA/JPL-Caltech Banner Image: NASA/JPL-Caltech

How Will the Europa Lander Search for Life?

An artist's rendering of the Europa mission's spacecraft. Main Image: NASA/JPL-Caltech Banner Image: NASA/JPL-Caltech
An artist's rendering of the Europa mission's spacecraft. Main Image: NASA/JPL-Caltech Banner Image: NASA/JPL-Caltech

Water, chemistry, energy: three key components for life. We only have confirmation of life on Earth so far, but we're always looking elsewhere. One of the biggest targets in the solar system is Europa, one of Jupiter's moons. We're aiming for that target with the Europa lander, which will launch for the Jovian moon around 2024. The mission will be the first on-site search for evidence of life on another world since Viking 1 and Viking 2 landed on Mars in 1976.

Last month, the team behind the Europa Lander released the mission’s scientific objectives [PDF], and at the recent 48th Lunar and Planetary Science Conference in The Woodlands, Texas, scientists answered questions and led a discussion about the trip with the wider planetary science community.

They explained that the Europa lander is not like the spacecraft Cassini or the Mars rovers—expeditions with big initial objectives, but quiet hope for decades of continued operation and science experiments. In contrast, this mission will live hard and die young. It will have to: The radiation environment at Europa is punishing, so the communications relay orbiter that will act as go-between for the lander and Earth won’t last more than a month or two. The lander will have enough power to run for just 20 days on the surface and will run on batteries; nuclear power was considered but discarded as being too expensive and challenging to launch. Batteries also have the advantage of being “quieter,” providing less vibration, magnetic, and electromagnetic disruption to sensitive instruments.

The lander will launch on a Space Launch System rocket and will spend years traveling to Europa. Upon arrival, the relay orbiter―which during the cruise phase to Jupiter acts as a carrier―will release the lander to Europa’s surface. As the communications satellite establishes its Europan orbit, the lander will use a mini sky crane system to land, looking and acting much like the rover Curiosity on Mars.

But notably, the scientists don’t call this process “Entry, Descent, and Landing” (EDL), but rather DDL, for Deorbit, Descent, and Landing—there’s no atmosphere around Europa for a lander to “enter.” This makes the job of landing much easier than on Mars, whose tenuous atmosphere is insufficient for parachutes alone, and yet enough that it makes a pure supersonic retropropulsive landing a challenge.

WHAT’S ON THE LANDER?

This artist's rendering illustrates a conceptual design for a potential future mission to land a robotic probe on the surface of Europa. Image Credit: NASA/JPL-Caltech

The lander is a square about the size of a large riding lawnmower with four long, articulated cricket-like legs that will each compress independently on landing, allowing it to touch down on an uncertain or jagged surface and still remain level. (If it landed on a ledge, for example, one leg might remain fully extended along the drop, and three legs might compress fully, bringing the belly of the robot even and near the ground.) A communications antenna will then deploy and establish communications with the relay orbiter.

The lander will host a payload of science instruments weighing nearly 94 pounds. “That is a considerable mass for getting science done on any world,” Kevin Hand of the Jet Propulsion Laboratory, co-chair of the science definition team, said. To get the science done, the lander will carry five instruments: a gas chromatograph mass spectrometer and a Raman spectrometer, which can identify the contents of a sample; a context camera, which should return some spectacular images, including a giant Jupiter hanging in the black sky over the ice world; and a geophone, used for seismometry, the study of seismic activity. Except for the camera, these instruments will live inside of the lander, which will protect them from the worst of the radiation.

The most crucial tool for gathering material is a sample collection arm: essentially an angled, twin-bladed boring instrument that will carve strips of granite-hard Europan surface at a depth of 4 inches or deeper. (Regolith at such a depth is not radiation-processed, increasing the likelihood of observing indicators of life.) The collected material will be loaded into a dock in the lander’s side, and the instruments within will begin their analyses. Over the course of the mission, the lander will collect and analyze a minimum of five samples with a minimum volume of .4 cubic inches from five different regions within the lander “workspace”―that is, the radial reach of the collector arm.

WHAT WILL WORKING ON EUROPA BE LIKE?

Two views of the trailing hemisphere of the ice-covered Europa. Image Credit: NASA/JPL/DLR

An Earth day is called a “day.” A Mars day is called a “sol.” A Europan day is called a “tal.” The carrier relay will orbit Europa every 24 hours―this is a happy coincidence with Earth, but wasn’t planned that way―and return three to four gigabits of data per orbit. Mission operations are therefore planned in 24-hour intervals.

At the start of a tal―00:00—the carrier relay will receive its commands from Earth to determine that period’s working schedule. The lander receives those instructions at 01:00, when the carrier is in view of the lander in its orbit. On an ordinary tal, the lander will start collecting samples for the next five hours. At 06:00, the lander will upload engineering data to the relay, which will, in turn, send that data to Earth.

The lander will then get to work on sample analysis, and at 11:00, upload its findings, and go to sleep. At this point, the carrier relay orbiter will be out of range of the lander. Two hours later, it will have a clear shot at Earth, and will send the data back here for analysis. Humans will use this data to plan the science and engineering for the next day, and will generate commands to that effect. At 23:00, those commands and instructions will be sent to the relay orbiter, and the cycle will repeat itself.

The baseline science mission will be achieved in 10 days. Depending on what the lander finds, the team might decide to prioritize different things—for example, focusing on collecting samples or image acquisition.

HOW WILL IT FIND LIFE?

Reddish spots and shallow pits pepper the ridged surface of Europa. Image Credit: NASA/JPL/University of Arizona/University of Colorado

There is no such thing as a “life detector.” Instead of a single magic reading, the lander will look for many organic biosignatures that, taken together, reveal life. Instruments will look for signs and abundance of organic material, cell-like structures, chirality (molecular properties, like those found in amino acids), and biominerals (minerals produced by living things)—among many other things.

Individually, none of these biosignatures can reveal life, but if found collectively, the evidence will be all but irrefutable. A biosignature matrix of positive and negative results is, in essence, plotted on a spreadsheet. Hand called this “biosignature bingo.” Not all of the biosignatures are necessary, but some combination of them are; finding, for example, an abundance of organics, cell patterns, chirality, and microscopic evidence but no signs of biominerals would still conclude life with certainty. On the other hand, if none of these features were found but biominerals and cell patterns were, we wouldn't call that evidence of life.

Sampling will be done in triplicate to confirm life findings. Three samples will have to confirm the biosignatures. The lander team is confident about this process. “It would be very hard to have a false positive, especially after replicating it three times,” Hand told mental_floss. “We use life on Earth as a guide, and so applying that matrix to life on Earth, both past and present, we would have a hard time leading to a false positive.”

The lander, of course, will not be the first spacecraft to arrive at the Jovian moon. The Europa Clipper spacecraft will have arrived and studied Europa years earlier, and will have ably characterized the habitability of that world. What Clipper finds, Lander will build upon. The Clipper’s work will determine one of four possible outcomes: Europa is not habitable, in which case the lander will figure out why (for example: geological activity); Europa is maybe habitable, in which case the lander will resolve the ambiguity of the finding; Europa is habitable, in which case the lander will try to find life; and Europa is inhabited―Clipper outright finds life on Europa, in which case the lander will confirm the finding and set the stage for future exploration. In addition, Clipper will act as a backup plan for the lander should the relay orbiter fail. The lander can talk to Clipper, which will in turn send the information back to Earth.

Despite the recent White House budget request that notably failed to earmark money for the Europa lander, these missions are realistically in no danger. Congressional appropriators have made it clear that the Europa lander is going to happen, and, just as in the case of Clipper (which the Office of Management and Budget ignored for years), it is still expected to receive billions of dollars over the next decade.

HOW DOES THIS COMPARE TO VIKING?

Images from the Viking mission on Mars. Image Credit: NASA

NASA undertook its last true life-finding mission—Viking’s mission to Mars—decades ago. There’s a reason for this time gap: Viking didn’t find life. Scientists had previously held out hope that animals might be scurrying about on the Martian surface. When the red planet was found to be creature-less, interest was quickly lost in the Mars program. Viking is thus sometimes criticized as being a failure. But Hand disagreed. “Viking is vindicated by Europa,” he said. “If Pathfinder had gone back and found a golf course on Mars, someone could say Viking made mistakes. Viking worked beautifully. Mars did not cooperate. Life detection experiments should provide valuable information, regardless of the biology results.”

Even in the absence of life, scientists will learn a lot about Europa as an ocean world, and as a world with liquid water recycling through the sea floor. In the absence of biology, they will still advance the sciences of geochemistry and oceanography.

“As exciting as a positive result for biosignatures would be, a negative result is equally profound. It gets to the question of what does it take for the origin of life to occur,” Hand said. Today, for example, hydrothermal vents are thought to have been critical to the birth of life on Earth. If Europa—which also has hydrothermal vents—is dead, perhaps hydrothermal vents are not that important after all.

Science has marched rapidly since the Viking missions, which means if life exists on Europa, we’re more likely to find it now than Viking scientists on Mars were. When the Viking landers set down in the mid-1970s, the structure of DNA had only been known for about 20 years. In the years since Viking, hydrothermal vents were discovered on Earth, and a whole new domain of life was discovered in the microbial realm, like cryptoendoliths in Antarctica—not to mention the “polymerase chain reaction” was developed, allowing the human genome to be sequenced. Last year, a new tree of life was created based on this research. So going into the lander mission, Hand and his team are cautiously optimistic.

“We don’t know if biology works beyond Earth,” Hand said. “We have every reason to believe it should and could, but we have yet to do that experiment.” The Europa lander team hopes to change that.

nextArticle.image_alt|e
iStock
15 Podcasts That Will Make You Feel Smarter
iStock
iStock

It's easy to feel overwhelmed by all the podcast options out there, but narrowing down your choices to the titles that will teach you something while you listen is a good place to start. If you're interested in learning more about philosophy, science, linguistics, or history, here are podcasts to add to your queue.

1. THE HABITAT

The Habitat is the closest you can get to listening to a podcast recorded on Mars. At the start of the series, five strangers enter a dome in a remote part of Hawaii meant to simulate a future Mars habitat. Every part of their lives over the next year, from the food they eat to the spacesuits they wear when they step outside, is designed to mimic the conditions astronauts will face if they ever reach the red planet. The experiment was a way for NASA to test plans for a manned mission to Mars without leaving Earth. The podcast, which is produced by Gimlet media and hosted by science writer Lynn Levy, ends up unfolding like a season of the Real World with a science fiction twist.

2. STUFF YOU SHOULD KNOW

Can’t pick a topic to educate yourself on? Stuff You Should Know from How Stuff Works is the podcast for you. In past episodes, hosts Chuck Bryant and Josh Clark (both writers at How Stuff Works) have discussed narwhals, Frida Kahlo, LSD, Pompeii, hoarding, and Ponzi schemes. And with three episodes released a week, you won’t go long without learning about a new subject.

3. THE ALLUSIONIST

Language nerds will find a kindred spirit in Helen Zaltzman. In each episode of her Radiotopia podcast The Allusionist, the former student of Latin, French, and Old English guides listeners through the exciting world of linguistics. Past topics include swearing, small talk, and the differences between British and American English.

4. PHILOSOPHIZE THIS!

Listening to all of Philosophize This! is cheaper than taking a philosophy class—and likely more entertaining. In each episode, host Stephen West covers different thinkers and ideas from philosophy history in an approachable and informative way. The show proceeds in chronological order, starting with the pre-Socratic era and leading up most recently to Jacques Derrida.

5. MORE PERFECT

In 2016, Radiolab, one of the most popular and well-established educational podcasts out there, launched a show called More Perfect. Led by Radiolab host Jad Abumrad, each episode visits a different Supreme Court case or event that helped shape the highest court in the land. Because of that, the podcast ends up being about a lot more than just the Supreme Court, exploring topics like police brutality, gender equality, and free speech online.

6. SLOW BURN

The Watergate scandal was such a important chapter in American history that it has its own suffix—but when asked to summarize the events, many people may draw a blank. Slow Burn, a podcast from Slate, gives listeners a refresher. In eight episodes, host Leon Neyfakh tells the story of the Nixon’s demise as it unfolded, all while asking whether or not citizens would be able to recognize a Watergate-sized scandal if it happened today.

7. LETTERS FROM WAR

Instead of using a broad scope to examine World War II, the Washington Post podcast Letters From War focuses on hundreds of letters exchanged by four brothers fighting in the Pacific during the period. Living U.S. military veterans tell the sibling's story while reflecting on their own experiences with war.

8. LEVAR BURTON READS

Just because you’re a grown-up doesn’t mean you have to miss out on the soothing sound of LeVar Burton’s voice reading to you. The former host of Reading Rainbow now hosts LeVar Burton Reads, a podcast from Stitcher aimed at adults. In each episode, he picks a different piece of short fiction to narrate: Just settle into a comfortable spot and listen to him tell stories by authors like Haruki Murakami, Octavia Butler, and Ursula K. Le Guin.

9. BRAINS ON!

Brains On! is an educational podcast for young audiences, but adults have something to gain from listening as well. Every week, host Molly Bloom is joined by a new kid co-host who helps her explore a different topic. Tune in for answers to questions like "What makes paint stick?" and "How do animals breathe underwater?"

10. SCIENCE VS

There’s a lot of misinformation out there—if you’re determined to sort out fact from fiction, it can be hard to know where to start. The team of “friendly fact checkers” at the Science Vs podcast from Gimlet is here to help. GMOs, meditation, birth control, Bigfoot—these are just a few of the topics that are touched upon in the weekly show. The goal of each episode is to replace any preconceived notions you have with hard science.

11. FLASH FORWARD

No one knows for sure what the future holds, but Flash Forward lays out the more interesting possibilities. Some of the potential futures that host and producer Rose Eveleth explores are more probable than others (a future where no one knows which news sources to trust isn’t hard to imagine; one where space pirates drag a second moon into orbit perhaps is), but each one is built on real science.

12. HIDDEN BRAIN

What motivates the everyday choices we make? That’s the question Shankar Vedantam tries to answer on the NPR podcast Hidden Brain. The show looks at how various unconscious patterns shape our lives, like what we wear and who we choose to spend time with.

13. PART-TIME GENIUS

The fact that it’s hosted by Mental Floss founders Will Pearson and Mangesh Hattikudur isn’t the only reason we love Part-Time Genius. The podcast from How Stuff Works wades into topics you didn’t know you were curious about, like the origins of Nickelodeon and the hidden secrets at the Vatican. Each episode will leave you feeling educated and entertained at the same time.

14. ASTRONOMY CAST

It’s a big universe out there—if you want to learn as much about it as possible, start with Astronomy Cast. Fraser Cain, publisher of the popular site Universe Today, and Dr. Pamela L. Gay, director of the virtual research facility CosmoQuest, host the podcast. They cover a wide range of topics, from the animals we’ve sent to orbit to the color of the universe.

15. SCIENCE OF HAPPINESS

The Science of Happiness podcast from PRI is here to improve your life, one 20-minute episode at a time. Science has proven that adopting certain practices, like mindfulness and gratitude, can make us happier—as does letting go of less unhealthy patterns like grudges and stressful thinking. With award-winning professor Dacher Keltner as your host, you can learn how to incorporate these science-backed strategies for happiness into your own life.

nextArticle.image_alt|e
ESO, A. Müller et al.
Here's the First Confirmed Image of a Planet Being Born
ESO, A. Müller et al.
ESO, A. Müller et al.

One of the newest landmarks in the observable universe has finally been captured, according to the European Southern Observatory. The image, snapped at its Very Large Telescope (VLT) in Chile, marks the first time a newborn planet has been seen as it forms. 

The image was documented by SPHERE, an instrument at the VLT that's built to identify exoplanets. It shows a planet, dubbed PDS 70b, taking shape in the disc of gas and star dust surrounding the young dwarf star PDS 70. In the past, astronomers have caught glimpses of what may have been new planets forming, but until now it had been impossible to tell whether such images just showed shapes in the dust or the beginnings of true planet formation. The results of the research will be shared in the journal Astronomy & Astrophysics [PDF].

This latest cornograph (an image that blocks the light of a star to make its surroundings visible) depicts the new planet clearly as a bright blob beside the black star. The two bodies may look close in the photo, but PDS 70b is roughly 1.8 billion miles from PDS 70, or the distance of Uranus to the Sun. SPHERE also recorded the planet's brightness at different wavelengths. Based on information gathered from the instrument, a team of scientists led by Miriam Keppler of the Max Planck Institute for Astronomy says that PDS 70b is a gas giant a few times the mass of Jupiter with a surface temperature around 1830°F and a cloudy atmosphere.

Astronomers known that planets form from solar clouds which stars leave behind when they come into a being, but until now, the details surrounding the phenomena have been mysterious. “Keppler’s results give us a new window onto the complex and poorly understood early stages of planetary evolution,” astronomer André Müller said in a press release. “We needed to observe a planet in a young star’s disc to really understand the processes behind planet formation.”

This is just the latest history-making image captured by the ESO's Very Large Telescope. In the last 20 years, it has documented nebulae, light from gravitational waves, and interacting galaxies.

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios