Jupiter’s moon of Europa has been the subject of much speculation and intrigue ever since it was first discovered by Galileo in 1610. In addition to having visible sources of (frozen) surface water and a tenuous oxygen atmosphere, it is also believed to boast interior oceans that could very well support life. As evidence for this mounts, plans to explore Europa using robot landers, miners, submersibles, or even manned missions have been floated by various sources.
However, it was this past December when astronomers announced that water plumes erupting 161 kilometers (100 miles) high from the moon’s icy south pole that things really took a turn. It was the best evidence to date that Europa, heated internally by the powerful tidal forces generated by Jupiter’s gravity, has a deep subsurface ocean. In part because of this, NASA recently issued a Request for Information (RFI) to science and engineering communities for ideas for a mission to the enigmatic moon. Any ideas need to address fundamental questions about the subsurface ocean and the search for life beyond Earth.
This is not the first time that NASA has toyed with the idea of investigating the Jovian moon for signs of life. Last summer, an article by NASA scientists was published in the peer-reviewed journal Astrobiology, which was entitled “Science Potential from a Europa Lander“. This article set out their research goals in more detail, and speculated how they might be practically achieved. At the time, the article indicated NASA’s ongoing interest, but this latest call for public participation shows that the idea is being taken more seriously.
This is positive news considering that NASA’s planned JIMO mission – Jupiter Icy Moon Orbiter, which was cancelled in 2005 – would be taking place by this time next year. Originally slated for launch between May and January of 2015/16, the mission involved sending a probe to Jupiter by 2021, which would then deploy landers to Callisto, Ganymede, Io and Europa for a series of 30 day studies. At the end of the mission in 2025, the vehicle would be parked in a stable orbit around Europa.
This is an opportunity to hear from those creative teams that have ideas on how we can achieve the most science at minimum cost… Europa is one of the most interesting sites in our solar system in the search for life beyond Earth. The drive to explore Europa has stimulated not only scientific interest but also the ingenuity of engineers and scientists with innovative concepts.
By opening the mission up to public input, it also appears that NASA is acknowledging the nature of space travel in the modern age. As has demonstrated with Chris Hadfield’s mission aboard the ISS, the Curiosity rover, as well as private ventures such as Mars One, Inspiration Mars, and Objective Europa – the future of space exploration and scientific study will involve a degree of social media and public participation never before seen.
The RFI’s focus is for concepts for a mission that costs less than $1 billion, but will cover five key scientific objectives that are necessary to improve our understanding of this potentially habitable moon. Primarily, the mission will need to:
- Characterize the extent of the ocean and its relation to the deeper interior
- Characterize the ice shell and any subsurface water, including their heterogeneity, and the nature of surface-ice-ocean exchange
- Determine global surface, compositions and chemistry, especially as related to habitability
- Understand the formation of surface features, including sites of recent or current activity, identify and characterize candidate sites for future detailed exploration
- Understand Europa’s space environment and interaction with the magnetosphere.
Although Europa has been visited by spacecraft and imaged distantly by Hubble, more detailed research is necessary to understand the complexities of this moon and its potential for life. NASA’s Galileo spacecraft, launched in 1989 was the only mission to visit Europa, passing close by the moon fewer than a dozen times. Ergo, if we’re ever to determine conclusively whether or not life exists there, we’re going to have to put boots (robotic or human) onto the surface and start digging!
To read the full Decadal Survey report on NASA’s website, click here.