This illustration of Jupiter's moon Europa shows how the icy surface may glow on its nightside, the side facing away from the Sun. Variations in the glow and the color of the glow itself could reveal information about the composition of ice on Europa's surface. Credit: NASA/JPL-Caltech
In a few years, NASA will be sending a spacecraft to explore Jupiter’s icy moon Europa. Known as the Europa Clipper mission, this orbiter will examine the surface more closely to search for plume activity and evidence of biosignatures. Such a find could answer the burning question of whether or not there is life within this moon, which is something scientists have speculated about since the 1970s.
In anticipation of this mission, scientists continue to anticipate what it will find once it gets there. For instance, scientists from NASA’s Jet Propulsion Laboratory recently conducted a study that showed how Europa might glow in the dark. This could be the result of Europa constantly being pummeled with high-energy radiation from Jupiter’s magnetic field, the study of which could tell scientists more about the composition of Europa’s ice.
In this decade and the next, some very impressive missions will take place. For instance, NASA will send its robotic Europa Clipper orbiter investigate Jupiter’s icy moon Europa for the first time. The orbiter will launch sometime in the middle of the decade (likely 2024) and arrive in the Jovian sytem in the 2030s to look for possible signs of life.
In preparation for this momentous event, NASA recently released a stunning new mission poster. As you can see, the poster features the orbiter looking down on Europa’s icy surface with Jupiter hanging in the background. The orbiter itself is in shadow so as to draw attention to the landscape beneath it.
A "true color" image of the surface of Jupiter's moon Europa as seen by the Galileo spacecraft. In 2030, the Europa Clipper mission will start its close flybys of this ocean world. Image credit: NASA/JPL-Caltech/SETI Institute
At first glance, Jupiter’s moon Europa doesn’t seem much like Earth. It’s a moon, not a planet, and it’s covered in ice. But it does have one important thing in common with Earth: a warm, salty ocean.
Now there’s even more evidence that Europa’s sub-surface ocean is habitable.
A "true color" image of the surface of Jupiter's moon Europa as seen by the Galileo spacecraft. In 2030, the Europa Clipper mission will start its close flybys of this ocean world. Image credit: NASA/JPL-Caltech/SETI Institute
Earlier this week, we shared some stunning, newly reprocessed images of Europa from NASA’s Galileo spacecraft, which visited Jupiter and its moons from December 1995 to September 2003. Now, as scientists continue to revisit Galileo’s data, even more details are coming into focus about Jupiter’s enticing moon. Not only is there evidence within the past few years of geysers shooting from Europa’s surface, twenty years ago, Galileo may have also witnessed a cryovolcanic eruptions — or plumes of water — spewing from the icy moon.
The fascinating surface of Jupiter’s icy moon Europa looms large in this newly-reprocessed color view, made from images taken by NASA's Galileo spacecraft in the late 1990s. This is the color view of Europa from Galileo that shows the largest portion of the moon's surface at the highest resolution. Credits: NASA/JPL-Caltech/SETI Institute
What’s been long-suspected has now been confirmed: Jupiter’s moon Europa has water. As we’ve learned more about the outer Solar System in recent years, Europa has become a high-priority target in the search for life. With this discovery, NASA has just painted a big red bulls-eye on Jupiter’s smallest Galilean moon.
Artist's concept of a Europa Clipper mission. Credit: NASA/JPL
In 2023, NASA plans to launch the Europa Clipper mission, a robotic explorer that will study Jupiter’s enigmatic moon Europa. The purpose of this mission is to explore Europa’s ice shell and interior to learn more about the moon’s composition, geology, and interactions between the surface and subsurface. Most of all, the purpose of this mission is to shed light on whether or not life could exist within Europa’s interior ocean.
This presents numerous challenges, many of which arise from the fact that the Europa Clipper will be very far from Earth when it conducts its science operations. To address this, a team of researchers from NASA’s Jet Propulsion Laboratory (JPL) and Arizona State University (ASU) designed a series of machine-learning algorithms that will allow the mission to explore Europa with a degree of autonom.
Artist's concept of a Europa Clipper mission. Credit: NASA/JPL
On August 19th, 2019, NASA announced that their Europa Clipper mission has been approved to move to the next phase of the mission, progressing to the final design stage.
Jupiter's moon Ganymede, the largest moon in the Solar System, seen orbiting Jupiter, the largest planet in the Solar System. This image was taken by the Cassini spacecraft. Image Credit: NASA/JPL/University of Arizona
Ganymede was shaped by pronounced periods of tectonic activity in the past, according to a new paper. It’s no longer active and its surface is more-or-less frozen in place now. But this discovery opens the door to better planning for future missions to Jupiter’s other frozen moon Europa. Unlike Ganymede, Europa is still tectonically active, and understanding past geological activity on Ganymede helps us understand present-day Europa.
The fascinating surface of Jupiter’s icy moon Europa looms large in this newly-reprocessed color view, made from images taken by NASA's Galileo spacecraft in the late 1990s. This is the color view of Europa from Galileo that shows the largest portion of the moon's surface at the highest resolution. Credits: NASA/JPL-Caltech/SETI Institute
Jupiter’s moon Europa has been the subject of fascination ever since the Pioneer 10 and 11 and Voyager1 and 2 missions passed through the system back in the 1970s. While the moon has no viable atmosphere and is bombarded by intense radiation from Jupiter’s powerful magnetic field, scientists believe that one of the most likely places to find life beyond Earth exists beneath its icy surface.
Little wonder then why multiple missions are being planned to study this moon up-close. However, if and when those missions reach Europa sometime in the next decade, they will have to contend with some sharp surface features that could make it hard to land. Such is the conclusion of a new study by researchers from Britain, the US and NASA’s Ames Research Center, which indicates that Europa’s surface is covered in bladed terrain.
Radiation from Jupiter can destroy molecules on Europa's surface. Material from Europa's ocean that ends up on the surface will be bombarded by radiation, possibly destroying any biosignatures, or chemical signs that could imply the presence of life. Credit: NASA/JPL-Caltech
Ever since the Galileo probe provided compelling evidence for the existence of a global ocean beneath the surface of Europa in the 1990s, scientists have wondered when we might be able to send another mission to this icy moon and search for possible signs of life. Most of these mission concepts call for an orbiter or lander than will study Europa’s surface, searching the icy sheet for signs of biosignatures turned up from the interior.
Unfortunately, Europa’s surface is constantly bombarded by radiation, which could alter or destroy material transported to the surface. Using data from the Galileo and Voyager 1 spacecraft, a team of scientists recently produced a map that shows how radiation varies across Europa’s surface. By following this map, future missions like NASA’s Europa Clipper will be able to find the spots where biosignatures are most likely to still exist.
As many missions have revealed by studying Europa’s surface, the moon experiences periodic exchanges between the interior and the surface. If there is life in its interior ocean, then biological material could theoretically be brought to the surface where it could be studied. Since radiation from Jupiter’s magnetic field would destroy this material, knowing where it is most intense, how deep it goes, and how it could affect the interior are all important questions.
Artist’s impression of water bubbling up from Europa’s interior ocean and breaching the surface ice. Credit: NASA/JPL-Caltech
As Tom Nordheim, a research scientist at NASA’s Jet Propulsion Laboratory, explained in a recent NASA press release:
“If we want to understand what’s going on at the surface of Europa and how that links to the ocean underneath, we need to understand the radiation. When we examine materials that have come up from the subsurface, what are we looking at? Does this tell us what is in the ocean, or is this what happened to the materials after they have been radiated?”
To address these question, Nordheim and his colleagues examined data from Galileo‘s flybys of Europa and electron measurements from NASA’s Voyager 1 spacecraft. After looking closely at the electrons blasting the moon’s surface, Nordheim and his team found that the radiation doses vary by location. The harshest radiation is concentrated in zones around the equator, and the radiation lessens closer to the poles.
Artist’s concept of a Europa Clipper mission. Credit: NASA/JPL
“This is the first prediction of radiation levels at each point on Europa’s surface and is important information for future Europa missions,” said Paranicas. Now that scientists know where to find regions least altered by radiation, they will be able to designate areas of study for the Europa Clipper, a JPL-led mission that is expected to launch as early as 2022.
For the sake of their study, Nordheim and his team went beyond a conventional two-dimensional map to build 3D models that examined how far below the surface the radiation penetrates. To test how deep organic material would have to be buried in order to survive, Nordheim and his team tested the effect of radiation on amino acids (the basic building blocks for proteins) to figure out how Europa’s exposure to radiation would affect potential biosignatures.
The results indicate how deep scientists will need to dig or drill during a potential future Europa lander mission in order to find any biosignatures that might be preserved. In the highest-radiation zones around the equator, the depth at which biosignatures could be found ranged from 10 to 20 cm (4 to 8 inches). At the middle- and high-latitudes, closer to the poles, the depths decrease to about 1 cm (0.4 inches). As Hand indicated:
“The radiation that bombards Europa’s surface leaves a fingerprint. If we know what that fingerprint looks like, we can better understand the nature of any organics and possible biosignatures that might be detected with future missions, be they spacecraft that fly by or land on Europa.”
Artist’s impression of a water vapor plume on Europa. Credit: NASA/ESA/K. Retherford/SwRI
When the Europa Clipper mission reaches the Jovian system, the spacecraft will orbit Jupiter and conducting about 45 close flybys of Europa. It’s advanced suite of scientific instruments will include cameras, spectrometers, plasma and radar instruments which will investigate the composition of the moon’s surface, its ocean, and material that has been ejected from the surface.
“Europa Clipper’s mission team is examining possible orbit paths, and proposed routes pass over many regions of Europa that experience lower levels of radiation,” Hand said. “That’s good news for looking at potentially fresh ocean material that has not been heavily modified by the fingerprint of radiation.”
With this new radiation map, the mission team will be able to narrow the range of possible research sites. This, in turn, will increase the likelihood that the orbiter mission will be able to settle the decades-old mystery of whether or not there is life in the Jovian system.
