Kevin Hand
The best chance of discovering life beyond Earth
may not be where you’d expect. Today’s weather forecast for Europa,
Jupiter’s fourth largest moon, is 280 degrees below Fahrenheit. A layer
of ice several miles thick coats its fractured surface, with 1,000-foot
ice cliffs piercing a pitch-black sky. It’s devoid of atmosphere,
bombarded by fierce radiation, about 485 million miles from the sun, at
times nearly 600 million miles from Earth—and Kevin Hand can hardly wait
to get there.
Hand works at the Jet Propulsion
Laboratory (JPL), which is under contract with NASA, researching Europa
and preparing to send an orbiting probe there. “When it comes to the
search for life beyond Earth, NASA’s mantra has long been ‘follow the
water.’ Well, the water is on Europa.” Planetary scientists believe a
global ocean of liquid water swirls beneath the icy surface. “Europa is
about the size of our own moon,” Hand explains. “Its vast ocean is
likely more than 60 miles deep (Earth’s ocean depths reach only about
seven miles). That means Europa may harbor two to three times the volume
of all liquid water on Earth.”
How do we know
the ocean exists? When the Galileo spacecraft explored Jupiter’s
neighborhood, it detected an induced magnetic field between the planet
and Europa. Hand notes that “ice isn’t conductive enough to create such a
field, so the best explanation is a region of salty, liquid water below
the frozen surface, which supplies a conductive layer. When you go
through a metal detector at the airport with a conductor such as keys in
your pocket, the alarm goes off. Likewise, when Galileo flew by, Europa
set off the alarm.”
Today Hand helps plan a
NASA mission to Europa to give Earthlings a closer look. The precise
timetable is uncertain, but an orbiting probe is projected to launch
sometime around 2020, make its six-year journey to Jupiter, then spend
two years touring the planet’s four largest moons before spiraling down
into orbit around Europa. “By the time we get there,” Hand observes,
“I’ll be a much older man. This business is not for the faint of heart.”
A large antenna and several cameras will transmit pictures and data.
The probe’s ice-penetrating radar will gather clues about the frozen
shell’s interior structure, possibly identifying where ice and ocean
meet. Other instruments will analyze surface chemistry, examine the
magnetic field, and investigate radiation environments.
To
create instruments that will travel hundreds of millions of miles
through space, Hand voyages to the most forbidding environments on
Earth. “I’m trying to understand extremes of life here, so we can better
assess and investigate habitable environments on alien worlds like
Europa.” He has explored the north slope of Alaska, the glaciers of
Mount Kilimanjaro, the valleys of Antarctica, and the depths of our
oceans to see how microbes eek out a living in our world’s harshest
climes. “One of my key challenges is figuring out how best to detect,
characterize, and map complex organic chemistry out there in the solar
system to see if Europa’s ice-covered ocean is, in fact, inhabited. The
new tools we’re developing at JPL will evolve and hopefully someday wind
up bolted to the side of a spacecraft or strapped to the end of a
robotic arm.”
Of course, no place on Earth can
match Europa’s true conditions. “That’s why my colleague Robert Carlson
and I have built what we call Europa-in-a-can, here in our lab,” Hand
explains. “It replicates low-temperature, low-pressure, high-radiation
environments, so we can study the chemical processes and dynamics that
may drive what we’ll see on distant worlds.” Their experiments also help
interpret data gained from the Galileo mission, and inform the design
of future missions and instruments.
“The
fundamental questions we’re trying to answer are questions humanity has
asked ever since we first gazed into the night sky: What is life and
could it exist out there beyond Earth? I want to know if DNA is the only
game in town. Are there different biochemical pathways that could lead
to other kinds of life? That’s at the heart of why I want to go to
Europa—to find something living in that ocean we can poke at and use to
understand and define life in a much more comprehensive way.”
For
someone focused on a world millions of miles away, Hand is remarkably
engaged in his own planet’s problems. “When I think about the desire to
connect with life elsewhere in the universe, it gives me an incredible
sense of the fragility of life here on Earth and how crucial it is to
protect our collective home.” This led him to found Cosmos Education, a
nonprofit working to advance critical thinking skills and empower some
of Africa’s poorest children through science, health, and environmental
education. “You can do all kinds of fun experiments with everyday items;
you don’t need elaborate resources. The activities we bring into
schools can be easily reproduced with materials found right in their
villages. We also do a lot of mentoring and career counseling. Our local
teams are made up of African engineers, teachers, scientists, health
activists, and development leaders who are amazing role models. We want
to inspire the next generation of great teachers, doctors, lawyers, and
politicians.”
Hand speaks from experience. His
own inspiration to study planetary science came in part from an engaging
elementary school science teacher and growing up under clear night
skies in Vermont. “Our complex industrial, technological society has
really disconnected us from the stars above. We need to remember to
stop, look up, and let the wonder take over.”