‘Planetary stethoscope’ helps ASU researchers study icy moon Europa

More from this show

A massive ocean lies underneath a shell of ice on Jupiter’s moon Europa. NASA has funded a seismometer being developed by Arizona State University researchers that would allow them to listen to what is underneath the ice to determine things like how thick the ice is, whether it holds pockets of water, and how often that water could spill through the surface through cracks in the ice shell. ASU seismologist Edward Garnero will tell us more about what’s being dubbed a “planetary stethoscope.”

TED SIMONS: YOU ARE WATCHING "ARIZONA HORIZON." UP NEXT, WE LEARN WHAT'S BENEATH THE ICE ON ONE OF THE MOONS OF JUPITER.

TED SIMONS: WHAT IS UNDER THE ICE OF JUPITER'S MOON, EUROPA? IT'S A QUESTION THAT COULD BE ANSWERED BY WAY OF A SEISMOMETER THAT'S BEING DEVELOPED BY RESEARCHERS AT ASU. HERE WE HAVE NOW IS ASU SEISMOLOGIST EDWARD GARNERO TO TELL US MORE ABOUT WHAT'S BEING CALLED A "PLANETARY STETHOSCOPE." EXPLAIN, PLEASE?

EDWARD GARNERO: IT SOUNDS GOOD, DOESN'T IT? JUST LIKE WHEN WE LOOK AT THE HUMAN BODY, WE WANT TO KNOW WHAT'S IN THERE. SOMETIMES WHEN THINGS AREN'T GOING WELL, WE DO THE SAME FOR PLANETS. EUROPA IS FASCINATING BECAUSE IT MIGHT BE THE MOST LIKELY PLACE FOR LIVE IN OUR SOLAR SYSTEM TODAY, IN THIS SALTY OCEAN BENEATH THE ICE. YOU CAN'T DRILL THAT DEEP. SO WE USE SEISMOMETORS, IT'S A FANCY WORD FOR SOMETHING THAT MEASURES VIBRATIONS AND WE LISTEN LIKE ULTRASOUND.

TED SIMONS: WE HAVE A SHOT OF EUROPA. JUST LOOK AT THE CRACKS. THOSE CRACKS ARE IN ICE, CORRECT? THE IDEA TO PUT A SIZE MONITOR ON THERE AND LISTEN TO THE ICE CRACK?

EDWARD GARNERO: ABSOLUTELY. EUROPA IS UNDER STRESS FROM JUPITER'S GRAVITY. THE ICE SHELL IS ACTUALLY DEFORMING AND CRACKING AND SO, YOU CAN HEAR THAT. IT'S NOT ONLY LIKE BEING ABLE TO DETECT HOW MUCH DOES THE ICE CRACK AND WHERE, IT'S THE SOURCE OF ENERGY YOU CAN USE TO IMAGE.

TED SIMONS: THERE ARE PLUMES. THERE ARE VISUALS OF PLUMES OF WATER SHOOTING UP OUT OF THE ICE. THAT MEANS SOMETHING IS THERE. YOU CAN SEE IT, CORRECT?

EDWARD GARNERO: YES

TED SIMONS: THE IDEA TO FIND OUT HOW MUCH WATER AND WHAT THE WATER'S DOING?

EDWARD GARNERO: WE HAVE A BUNCH OF QUESTIONS WE WOULD LOVE TO ADDRESS. ONE OF THEM, IF WATER IS A KEY INGREDIENT OF LIFE, AND YOU LAND THIS TINY THING LIKE THE SIZE OF A MINI COOPER, OR A SMART CAR BUT NOT SO TALL. PEOPLE ARE THINKING ABOUT THE DESIGNS RIGHT NOW. YOU LANDED ON THE SURFACE. HOW CAN YOU ADDRESS THE QUESTION, IS THERE LIFE ON THE BODY? ONE THING TO DO, HOW THICK IS THE ICE SHELL? ARE THERE POCKETS OF WATER IN THE ICE AROUND THE LANDER. IF THERE ARE POCKETS OF ICE, THERE MIGHT BE INTERESTING CHEMISTRY.

TED SIMONS: CORRECT ME IF I'M WRONG, BUT YOU HAVE A VISUAL OF A DARK SPOT OF MINERALS DEPOSITED BY THE WATER THAT EXISTS. YOU WANT TO GET CLOSE TO ONE OF THOSE AS POSSIBLE, RIGHT?

EDWARD GARNERO: ABSOLUTELY.

TED SIMONS: AGAIN, AS FAR AS THE WATER BEING SUBMERGED UNDERNEATH IT, WE HAVE A CROSS SECTION OF THE ICE. THAT COULD BE AN OCEAN UNDER THERE ORE LAKES BENEATH THE SURFACE.

EDWARD GARNERO: OR BOTH. YOU CAN'T ANSWER THAT QUESTION WITH GREAT CERTAINTY FROM PHOTOGRAPHS VERY FAR AWAY, SO YOU HAVE TO GET DOWN THERE. ECONOMICALLY, CAN YOU IMAGINE PUTTING A DEVICE ON A FAR AWAY MOON THAT DRILLS VERY DEEP, THAT'S NOT EASY, SO IT'S EASIER TO LISTEN. IT'S THE SAME WITH OUR BODY, LISTENING WITH MRI OR CAT SCAN OR ULTRASOUND --

TED SIMONS: YOU ARE HEARING CRACKS, POPS, CAN YOU HEAR ACTUALLY WATER MOVING?

EDWARD GARNERO: I DON'T KNOW. I WOULD IMAGINE THE CRACKS AND POPS ARE LIKE IT. WE MIGHT CALL THEM ICE QUAKES. IT HAPPENS IN GREEN LAND AS THE ATMOSPHERE IS WARMING UP AND MORE ICE IS MELTING. YOU HEAR THE ICE DOING THE CRACKING.

TED SIMONS: THAT'S FASCINATING. YOU SAY IT'S THE SIZE OF A MINICOOPER?

EDWARD GARNERO: NO, I'M SORRY, THAT'S THE SIZE OF THE LANDER. THE BIG BOX WITH LEGS THAT WILL SETTLE DOWN ON THE SURFACE. SEISMOMETER, THE CENSOR, THE SIZE OF OLD FILM CANISTERS BEFORE DIGITAL DEVICES, AND THEN THERE ARE FOUR OF THEM TOGETHER, LIKE SHOWN IN THIS IMAGE WHERE THEY ARE ALL POINTING IN DIFFERENT DIRECTIONS. THERE IS AN EXTRA ONE IN CASE ONE CRAPS OUT. THAT ALLOWS THE VIBRATIONS TO BE MEASURED SO WE COULD TELL WHICH WAY ENERGY IS COMING FROM. THAT PACKAGE IS A LITTLE BIG BIGGER THAN A LARGE COFFEE MUG. IF YOU COULD HAVE ONE OF THOSE ON EACH LEG OF THE LANDER, THAT WILL ENABLE US TO IMAGE THE SUBSURFACE.

TED SIMONS: THE SUBSURFACE THERE. YOU NEVER KNOW WHAT'S A MILE OR TWO AROUND THE CORNER, DO YOU?

EDWARD GARNERO: ABSOLUTELY. SEISMOLOGISTS ARE GREEDY. WE WANT MORE DATA, MORE INSTRUMENTS EVERYWHERE. IT REALLY IS, IF YOU HAD TO PLUG ONE EAR AND SAY WHERE SOMETHING'S COMING FROM, IT'S MORE DIFFICULT. THE MORE WE HAVE, THE MORE ACCURATELY YOU CAN DETERMINE THE CHARACTER OF WHAT'S COMING.

TED SIMONS: THE SIZE MONITOR, IS IT HELPING WITH THE QUALITY OF SENSORS IN GENERAL?

EDWARD GARNERO: YES AND NO. ON EARTH THERE ARE DETAILED CENSORS. THEY GET BIG ENOUGH WHERE IT'S NOT ECONOMICALLY FEASIBLE TO SEND A BUNCH OF THEM TO A FAR AWAY PLANET. THIS IS DESIGNED WITH FLUID AND A MICROCHIP THAT MEASURES THE FLUID. THE BENEFIT IS THAT THEY ARE DURABLE. YOU COULD THROW IT AT A PLANET FROM AN ORBIT.

TED SIMONS: WHEN IT LANDS, DOES IT HAVE RUBBER FEELLIES AT THE BOTTOM? IT NEEDS TO STAY STILL, DOESN'T IT?

EDWARD GARNERO: YOU DON'T WANT IT TO BOUNCE AROUND. THAT TECHNOLOGY IS CALLED A "PENETRATOR." YOU PUT IT IN LIKE SOMETHING HEAVY AND POINTED SO IT JABS INTO THE SURFACE. FOR EUROPA, WE EXPECT NASA WILL SEND A LANDER, SOMETHING THAT LANDS ON THE SURFACE.

TED SIMONS: WHEN YOU SAY THAT, WE GET TO THE POINT OF THE FACT THAT WE DON'T HAVE THE MISSION GOING YET, DO WE? OR DO WE?

EDWARD GARNERO: THAT'S CORRECT. NASA HAS ANNOUNCED IT MAY DO A CALL FOR PROPOSALS FOR THE FIRST PHASE OF STUDYING THE FEASIBILITY OF INSTRUMENTS THAT COULD GO ON IF IT'S FUNDED.

TED SIMONS: HOW LONG DOES IT TAKE FOR THE SEISMOMETER TO GO TO BE OPERATIONAL?

EDWARD GARNERO: IT COULD BE A FEW YEARS. RIGHT NOW THE CENSOR IS BEING DEVELOPED. THERE ARE PARTS OF IT THAT RECORD IT AND POWER IT AND TRANSFER THE INFORMATION.

TED SIMONS: SO SENDING A LANDER, THE MINICOOPER THING. THE SMART CAR. WHEN IS THAT GOING TO BE READY TO GO AND LAND ON EUROPA?

EDWARD GARNERO: IT'S MANY YEARS FROM NOW. IT'S A LONG JOURNEY GETTING THERE AS WELL. IF NASA DECIDES TO HAVE A PROGRAM TO SEND A LANDER TO EUROPA, IT COULD BE THAT SORT OF THING, AND I'M GUESSING, IT COULD BE IN THE EARLY 2020s.

TED SIMONS: GOOD LUCK.

EDWARD GARNERO: THANK YOU.

TED SIMONS: YOU WILL BE READY, I IMAGINE. THANK YOU FOR BEING HERE.

EDWARD GARNERO: THANK YOU FOR HAVING ME.

Edward Garnero: ASU Seismologist

Illustration of columns of a capitol building with text reading: Arizona PBS AZ Votes 2024

Arizona PBS presents candidate debates

An armed forces bugler playing the trumpet in front of the United States Capitol building.
aired May 26

National Memorial Day Concert 2024

Graphic for the AZPBS kids LEARN! Writing Contest with a child sitting in a chair writing on a table and text reading: The Ultimate Field Trip
May 26

Submit your entry for the 2024 Writing Contest

Rachel Khong
May 29

Join us for PBS Books Readers Club!

Subscribe to Arizona PBS Newsletters

STAY in touch
with azpbs.org!

Subscribe to Arizona PBS Newsletters: