For decades, evidence has been mounting that beneath the icy crust of Jupiter’s moon Europa, a vast ocean exists that could possibly host microbial life. As scientists prepare to send the Europa Clipper mission to orbit the Jupiter system, they are trying to learn more about the subsurface ocean and the ice that encompasses the moon.
One way to study Europa is to look at similar environments here on Earth. Scientists say that conditions found under Earth’s Antarctic ice shelf provides an analog to Europa’s subsurface ocean and can help them determine how the moon’s ice shell accretes and grows.
A new study published in the journal Astrobiology looked at a unique phenomenon in the Antarctic ocean called underwater snow. This is where ice floats upwards onto the bottom of the ice shelf and attaches in fluffy-looking mounds. This helps to replenish the ice shelf. The study infers that the same phenomenon is likely true for Jupiter’s moon, and may play a role in building and replenishing its exterior ice shell.
While NASA’s much-lauded Space Launch System stands ready for its maiden flight later this month with the goal of sending astronauts back to the Moon in the next few years, our gazes once again turn to the stars as we continue to ask the question that has plagued humankind since time immemorial: Are we alone? While there are several solar system locales that we can choose from to conduct our search for life beyond Earth, to include Mars and Saturn’s moons, Titan and Enceladus, one planetary body orbiting the largest planet in the solar system has peaked the interest of scientists since the 1970s.
When Galileo pointed his telescope at Jupiter 400 years ago, he saw three blobs of light around the giant planet, which he at first thought were fixed stars. He kept looking, and eventually, he spotted a fourth blob and noticed the blobs were moving. Galileo’s discovery of objects orbiting something other than Earth—which we call the Galilean moons in his honour—struck a blow to the Ptolemaic (geocentric) worldview of the time.
Galileo couldn’t have foreseen the age of space exploration that we’re living in now. Fast forward 400 years, and here we are. We know the Earth doesn’t occupy any central point. We’ve discovered thousands of other planets, and many of them will have their own moons. Galileo would be amazed at this.
What would he think about robotic missions to explore one of the blobs of light he spotted?
Are we alone? Is there life beyond Earth? These are the questions that plague the very essence of science, and in particular, planetary science. Unfortunately, robotic exploration of exoplanetary systems currently remains out of reach due to the literal astronomical distances to get there. For context, our nearest star, Proxima Centauri, is 4.25 light years away, or a mind-blowing 40,208,000,000,000 km (25,000,000,000,000 miles) from Earth. Finding an intelligent civilization might be out of reach for now but searching for any forms of life beyond Earth is very much possible within the confines of our own solar system.
Beneath the surface of Jupiter’s icy moon Europa, there’s an ocean up to 100 km (62 mi) deep that has two to three times the volume of every ocean on Earth combined. Even more exciting is how this ocean is subject to hydrothermal activity, which means it may have all the necessary ingredients for life. Because of this, Europa is considered one of the most likely places for extraterrestrial life (beyond Mars). Hence, mission planners and astrobiologists are eager to send a mission there to study it closer.
Unfortunately, Europa’s icy surface makes the possibility of sampling this ocean rather difficult. According to the two predominant models for Europa’s structure, the ice sheet could be a few hundred meters to several dozen kilometers thick. Luckily, new research by a team from Stanford University has shown that Europa’s icy shell may have an abundance of water pockets inside, as indicated by features on the surface that look remarkably like icy ridges here on Earth.
Who is excited to send a spacecraft to Europa? Every person I’ve talked to who is even remotely interested in planetary exploration is incredibly enthusiastic about the upcoming Europa Clipper mission to explore Jupiter’s icy moon. With strong evidence of a subsurface liquid ocean, Europa is considered by many to be the most likely place in our Solar System – besides Earth — which might harbor life. The many mysteries about this moon make it a compelling place to explore.
The highly anticipated Europa Clipper mission, set to launch in 2024, will investigate Jupiter’s moon Europa. This icy moon with a subsurface ocean is considered one of the most enticing places in our Solar System where life might exist. To look beneath Europa’s icy crust, the Clipper mission has a host of instruments looking for plumes and ‘hot spots.’
NASA’s Europa Clipper is one of the most anticipated missions of the coming decade, in large part because its target, the large Jovian moon Europa, is considered one of the most likely places in our solar system that extraterrestrial life might exist. If Europa is harboring alien microbes, however, they’re likely to be buried deep beneath the moon’s thick icy crust in a vast subsurface ocean. Unlocking the secrets of this water world isn’t going to be easy, but the Clipper team has a plan to make the most of the opportunity they have: If you can’t get to the ocean, let the ocean come to you.
Since the Voyager probes passed through the Jupiter system in 1979, scientists have been intrigued and mystified by its moon Europa. Once the images these probes acquired of the moon’s icy surface returned to Earth, scientists began to speculate about the possibility of a subsurface ocean. Since then, the detection of plume activity and other lines of evidence have bolstered this theory and fed speculation that there could be life beneath Europa’s icy surface.
According to new research, another critical piece of evidence of Europa’s watery nature has at least been confirmed. Using a similar technique that confirmed the presence of atmospheric water vapor in Jupiter’s moon Ganymede, Lorenz Roth of the KTH Royal Institute of Technology confirmed that Europa has water vapor in its atmosphere. This discovery could lead to a greater understanding of Europa’s atmosphere and surface environment, informing missions headed there in the near future.