24/7 Space News
OUTER PLANETS
A Jovian journey to the icy worlds of a Gas Giant
When Galileo discovered these moons in 1609, they were the first objects known to directly orbit another planet. Their discovery was the final nail in the coffin of the theory that Earth - and humanity - resides at the center of the universe. Maybe these worlds have another humbling surprise in store.
ADVERTISEMENT
A Jovian journey to the icy worlds of a Gas Giant
by Mike Sori | Planetary Science - Purdue University
West Lafayette IN (SPX) Apr 11, 2023

On April 13, 2023, the European Space Agency is scheduled to launch a rocket carrying a spacecraft destined for Jupiter. The Jupiter Icy Moons Explorer - or JUICE - will spend at least three years on Jupiter's moons after it arrives in 2031. In October 2024, NASA is also planning to launch a robotic spacecraft named Europa Clipper to the Jovian moons, highlighting an increased interest in these distant, but fascinating, places in the solar system.

I'm a planetary scientist who studies the structure and evolution of solid planets and moons in the solar system.

There are many reasons my colleagues and I are looking forward to getting the data that JUICE and Europa Clipper will hopefully be sending back to Earth in the 2030s. But perhaps the most exciting information will have to do with water. Three of Jupiter's moons - Europa, Ganymede and Callisto - are home to large, underground oceans of liquid water that could support life.

Meet Io, Europa, Ganymede and Callisto
Jupiter has dozens of moons. Four of them in particular are of interest to planetary scientists.

Io, Europa, Ganymede and Callisto are, like Earth's Moon, relatively large, spherical complex worlds. Two previous NASA missions have sent spacecraft to orbit the Jupiter system and collected data on these moons. The Galileo mission orbited Jupiter from 1995 to 2003 and led to geological discoveries on all four large moons. The Juno mission is still orbiting Jupiter today and has provided scientists with an unprecedented view into Jupiter's composition, structure and space environment.

These missions and other observations revealed that Io, the closest of the four to its host planet, is abuzz with geological activity, including lava lakes, volcanic eruptions and tectonically formed mountains. But it is not home to large amounts of water.

Europa, Ganymede and Callisto, in contrast, have icy landscapes. Europa's surface is a frozen wonderland with a young but complex history, possibly including icy analogs of plate tectonics and volcanoes. Ganymede, the largest moon in the entire solar system, is bigger than Mercury and has its own magnetic field generated internally from a liquid metal core. Callisto appears somewhat inert compared to the others, but serves as a valuable time capsule of an ancient past that is no longer accessible on the youthful surfaces of Europa and Io.

Most exciting of all: Europa, Ganymede and Callisto all almost certainly possess underground oceans of liquid water.

Ocean worlds
Europa, Ganymede and Callisto have chilly surfaces that are hundreds of degrees below zero. At these temperatures, ice behaves like solid rock.

But just like Earth, the deeper underground you go on these moons, the hotter it gets. Go down far enough and you eventually reach the temperature where ice melts into water. Exactly how far down this transition occurs on each of the moons is a subject of debate that scientists hope to resolve with JUICE and Europa Clipper. While the exact depths are still uncertain, scientists are confident that these oceans exist.

The best evidence of these oceans comes from Jupiter's magnetic field. Saltwater is electrically conductive. So as these moons travel through Jupiter's magnetic field, they generate a secondary, smaller magnetic field that signals to researchers the presence of an underground ocean. Using this technique, planetary scientists have been able to show that the three moons contain underground oceans. And these oceans are not small - Europa's ocean alone might have more than double the water of all of Earth's oceans combined.

An obvious and tantalizing next question is whether these oceans can support extraterrestrial life. Liquid water is an important piece of what makes for a habitable world, but far from the only requirement for life. Life also needs energy and certain chemical compounds in addition to water to flourish. Because these oceans are hidden beneath miles of solid ice, sunlight and photosynthesis are out. But it's possible other sources could provide the needed ingredients.

On Europa, for example, the liquid water ocean overlays a rocky interior. That rocky seafloor could provide energy and chemicals through underwater volcanoes that could make Europa's ocean habitable. But it is also possible that Europa's ocean is a sterile, inhospitable place - scientists need more data to answer these questions.

Upcoming missions from ESA and NASA
JUICE and Europa Clipper are set up to give scientists game-changing information about the potential habitability of Jupiter's moons. While both missions will gather data on multiple moons, JUICE will spend time orbiting and focusing on Ganymede, and Europa Clipper will make dozens of close flybys of Europa.

Both of the spacecraft will carry a suite of scientific instruments built specifically to investigate the oceans. Onboard radar will allow JUICE and Europa Clipper to probe into the moons' outer layers of solid ice. Radar could reveal any small pockets of liquid water in the ice, or, in the case of Europa, which has a thinner outer ice layer than Ganymede and Callisto, hopefully detect the larger ocean.

Magnetometers will also be on both missions. These tools will give scientists the opportunity to study the secondary magnetic fields produced by the interaction of conductive oceans with Jupiter's field in great detail and will hopefully give researchers clues to salinity and volumes of the oceans.

Scientists will also observe small variations in the moons' gravitational pulls by tracking subtle movements in both spacecrafts' orbits, which could help determine if Europa's seafloor has volcanoes that provide the needed energy and chemistry for the ocean to support life.

Finally, both craft will carry a host of cameras and light sensors that will provide unprecedented images of the geology and composition of the moons' icy surfaces.

Maybe one day, a spacecraft will be able to drill through the miles of solid ice on Europa, Ganymede or Callisto and explore oceans directly. Until then, observations from spacecraft like JUICE and Europa Clipper are scientists' best bet for learning about these ocean worlds.

When Galileo discovered these moons in 1609, they were the first objects known to directly orbit another planet. Their discovery was the final nail in the coffin of the theory that Earth - and humanity - resides at the center of the universe. Maybe these worlds have another humbling surprise in store.

Related Links
Jupiter Icy Moons Explorer
Purdue University
The million outer planets of a star called Sol

Subscribe Free To Our Daily Newsletters

RELATED CONTENT
The following news reports may link to other Space Media Network websites.
OUTER PLANETS
Guiding JUICE to Jupiter
Paris, France (SPX) Apr 11, 2023
This phenomenal endeavour, led by the European Space Agency, is powered by Airbus technology. Our engineers have rarely faced a greater challenge than enabling such a journey. The JUICE probe will encounter extreme temperatures, intense radiation and decreasing solar energy during its 5 billion kilometre journey. Being self-sufficient in energy generation and storage is key to the mission's success. Operating in the outer reaches of the solar system, far from the Sun, JUICE uses large solar arrays ... read more

ADVERTISEMENT
ADVERTISEMENT
OUTER PLANETS
Rocket Lab launches new constellation-class star tracker

Russia will use International Space Station 'until 2028'

NASA Boosts Open Science through Innovative Training

Orion stretches its wings ahead of first crewed Artemis mission

OUTER PLANETS
Elon Musk forms X.AI artificial intelligence company

SpaceX will try to launch most powerful rocket ever Monday

China bans ships from area north of Taiwan Sunday due to 'falling rocket wreckage'

SpaceX prepares for rehearsal, test flight of Starship rocket

OUTER PLANETS
Curiosity gets a major software upgrade

Ingenuity Mars Helicopter completes 50th flight

NASA unveils 'Mars' habitat for year-long experiments on Earth

Slip and Pivot: Sol 3797

OUTER PLANETS
China's inland space launch site advances commercial services

China's Shenzhou XV astronauts complete 3rd spacewalk

China's Shenzhou-15 astronauts to return in June

China's space technology institute sees launches of 400 spacecraft

OUTER PLANETS
'The Space Economy' - an Essential Guide for Investors and Entrepreneurs

Viasat confirms ViaSat-3 Americas set to launch

Taiwan seeks satellite solutions after undersea cables cut

Safran to provide GNSS simulation solutions for Xona's LEO constellation

OUTER PLANETS
Intelsat to Extend Life of Satellite with new Mission Extension Pod

3D-printed rocket maker to focus on bigger vehicle for commercial launches

Tendeg selected by Lockheed Martin as strategic supplier of deployable antennas

SatixFy and Presto Engineering test rad-hard space-grade ASICs

OUTER PLANETS
HD 169142 b, the third protoplanet confirmed to date

Do Earth-like exoplanets have magnetic fields

New paper investigates exoplanet climates

JWST confirms giant planet atmospheres vary widely

OUTER PLANETS
Europe's JUICE mission blasts off towards Jupiter's icy moons

Juno Marks 50 Orbits Around Jupiter

A Jovian journey to the icy worlds of a Gas Giant

Guiding JUICE to Jupiter

Subscribe Free To Our Daily Newsletters


ADVERTISEMENT



The content herein, unless otherwise known to be public domain, are Copyright 1995-2023 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.