by Jia-Rui C. Cook
August 7, 2013
concept of Europa and Jupiter
This artist's concept shows a simulated view from
the surface of
Jupiter's moon Europa.
Image Credit: NASA/JPL-Caltech
Most of what scientists know of
Jupiter's moon Europa they have
gleaned from a dozen or so close flybys from NASA's Voyager 2
spacecraft in 1979 and NASA's Galileo spacecraft in the mid-to-late
Even in these fleeting, paparazzi-like
encounters, scientists have seen a fractured, ice-covered world with
tantalizing signs of a liquid water ocean under its surface.
Such an environment could potentially be
a hospitable home for microbial life.
A new study in the journal Astrobiology
Potential from a Europa Lander) authored by a
NASA-appointed science definition team lays out their consensus on
the most important questions to address.
"If one day humans send a robotic
lander to the surface of Europa, we need to know what to look
for and what tools it should carry," said Robert Pappalardo, the
study's lead author, based at NASA's Jet Propulsion Laboratory,
"There is still a lot of preparation
that is needed before we could land on Europa, but studies like
these will help us focus on the technologies required to get us
there, and on the data needed to help us scout out possible
Europa is the most likely place in
our solar system beyond Earth to have life today, and a landed
mission would be the best way to search for signs of life."
The paper was authored by scientists
from a number of other NASA centers and universities, including,
the Johns Hopkins University
Applied Physics Laboratory, Laurel, Md.
University of Colorado, Boulder
University of Texas, Austin
the NASA Goddard Space Flight
Center, Greenbelt, Md.
This graphic shows a
possible robotic lander
for a future mission
to Jupiter's moon Europa.
Image Credit: NASA/JPL-Caltech
This view of Jupiter's moon Europa features
regional-resolution mosaics overlaid on a lower resolution global
view for context.
Image Credit: NASA/JPL-Caltech/University of Arizona
The team found the most important
questions clustered around composition:
What makes up the reddish
"freckles" and reddish cracks that stain the icy surface?
What kind of chemistry is
Are there organic molecules,
which are among the building blocks of life?
Additional priorities involved improving
our images of Europa - getting a look around at features on a human
scale to provide context for the compositional measurements.
Also among the top priorities were
questions related to geological activity and the presence of liquid
How active is the surface?
How much rumbling is there from
the periodic gravitational squeezes from its planetary host,
the giant planet Jupiter?
What do these detections tell us
about the characteristics
of liquid water below the
"Landing on the surface of Europa
would be a key step in the astrobiological investigation of that
world," said Chris McKay, a senior editor of the journal
Astrobiology, who is based at NASA Ames Research Center, Moffett
"This paper outlines the science
that could be done on such a lander. The hope would be that
surface materials, possibly near the linear crack features,
include biomarkers carried up from the ocean."
This work was conducted with Europa
study funds from NASA's Science Mission Directorate, Washington,
D.C. JPL is a division of the California Institute of Technology,