JupiterEuropa’s moon has an icy crust covering a vast global ocean. The rock layer below can be hot enough to melt, leading to underwater volcanoes.
New research and computer modeling show that volcanic activity may have occurred on the seabed of Jupiter Europa’s moon in the recent past – and may still occur. NASAThe next Europa Clipper mission, which aims to launch in 2024, will get closer to the frozen moon and collect metrics that may shed light on recent discoveries.
Scientists have strong evidence that Europa is home to a huge ocean between its icy crust and rocky interior. The new work shows how the moon can have enough internal heat to partially melt this rock layer, a process that could feed volcanoes on the ocean floor. Recent 3D modeling of how this internal heat is produced and transferred is the most detailed and in-depth examination to date of the effect of this internal heating on the moon.
The key to making Europe’s rock mantle warm enough to melt is Jupiter’s massive gravitational pull on its moons. As Europa circles the gas giant, the interior of the frozen moon flexes. Bending forces energy inside the moon, which then seeps in as heat (think of how repeatedly bending a paperclip generates heat). The more the interior of the moon flexes, the more heat is generated.
The research, recently published in Geophysical research letters, models in detail how the rocky part of Europa can flex and heat under the pull of gravity from Jupiter. It shows where the heat dissipates and how it melts this rocky mantle, increasing the likelihood of volcanoes on the seabed.
Volcanic activity over Europe has been a subject of speculation for decades. By comparison, Jupiter’s moon Io is obviously volcanic. Hundreds of volcanoes erupt from lava fountains and eject volcanic gas and dust up to 400 kilometers high – an activity that is due to the same type of internal heating caused by Jupiter’s pull. But Europa is further away than Io from its host planet, so scientists wondered if the effect would be similar below the icy surface.
Led by Marie Běhounková of Charles University in the Czech Republic, the authors further predicted that volcanic activity is more likely to occur near the poles of Europe – the latitudes where the most heat is generated. They also looked at how volcanic activity may have changed over time. Long-lived energy sources offer more possibilities for the development of potential life.
Underwater volcanoes, if present, could fuel hydrothermal systems like those that fuel life deep in Earth’s oceans. On Earth, when seawater comes in contact with hot magma, the interaction results in chemical energy. And it is the chemical energy of these hydrothermal systems, rather than that of sunlight, that helps support life deep within our own oceans. Volcanic activity on the seabed of Europe would be one way to support a potential habitable environment in this moon’s ocean.
“Our results provide further evidence that Europe’s subterranean ocean can be an environment for the emergence of life,” said Běhounková. “Europe is one of the few planetary bodies that could have maintained volcanic activity for billions of years, and perhaps the only one beyond Earth that has large reservoirs of water and a source of long-lasting energy.
NASA scientists will have the opportunity to put the new predictions to the test when Europa Clipper reaches its target in 2030. The spacecraft will orbit Jupiter and perform dozens of close flyovers of Europa to map the moon and study its composition. Among the scientific data it collects, the spacecraft will monitor the surface in detail and sample the thin atmosphere of the moon.
Surface and atmospheric observations will give scientists a chance to learn more about the moon’s inner ocean if water percolates through the icy crust. Scientists believe that the exchange of matter between the ocean and the crust would leave traces of seawater on the surface. They also believe the exchange may emit gas, and possibly even plumes of water vapor, with ejected particles that could contain material from the seabed.
As Europa Clipper measures the moon’s gravity and magnetic field, anomalies in these areas, especially towards the poles, could help confirm the volcanic activity predicted by the new research.
“The prospect of a hot, rocky interior and volcanoes on the European seabed increases the chances that the European ocean will be a habitable environment,” said Robert Pappalardo, Project Scientist, Europa Clipper, Jet Propulsion NASA Laboratory in Southern California. “We may be able to test this with the gravity and composition measurements predicted by Europa Clipper, which is an exciting prospect.”
Reference: “Magmatic pulsations induced by the tides on the ocean floor of Jupiter’s Moon Europa” by Marie Běhounková, Gabriel Tobie, Gaël Choblet, Mathilde Kervazo, Mohit Melwani Daswani, Caroline Dumoulin and Steven D. Vance, December 22, 2020, Geophysical research letters.
DOI: 10.1029 / 2020GL090077
Learn more about the mission
Missions like Europa Clipper contribute to the field of astrobiology, interdisciplinary research into the variables and conditions of distant worlds that might harbor life as we know it. Although Europa Clipper is not a life-detecting mission, she will perform a detailed reconnaissance of Europa and examine whether the frozen moon, with its subterranean ocean, has the capacity to support life. Understanding the habitability of Europa will help scientists better understand how life developed on Earth and the potential to find life beyond our planet.
Managed by Caltech in Pasadena, CA, JPL leads the development of the Europa Clipper mission in partnership with the Johns Hopkins Applied Physics Lab (APL) in Maryland for the agency’s Science Missions Directorate in Washington. The Planetary Missions Program Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama, performs program management for the Europa Clipper mission.