Space scientists are always searching for places where life beyond Earth might exist. One of the most exciting locations is Europa, a moon of Jupiter. Europa has a huge ocean hidden under a thick layer of ice. Recently, new data from NASA’s Juno spacecraft has given scientists a better idea of how thick that ice really is.
This discovery is very important because the thickness of Europa’s ice shell can help experts understand whether life could survive there.
Let’s break it down in simple words and understand what this new research means.
What Is Europa and Why Is It Special?
Europa is one of the many moons of Jupiter. It is slightly smaller than Earth’s moon. What makes Europa special is that scientists believe it has a large subsurface ocean under its icy surface.
This hidden ocean makes Europa one of the top places in our solar system where alien life might exist. Water is one of the main requirements for life, and Europa may have more water than all of Earth’s oceans combined.
How Did Scientists Study Europa’s Ice?
The information comes from Juno, a spacecraft launched by NASA. Juno has been orbiting Jupiter since July 2016.
During a close flyby on September 29, 2022, Juno came within 360 kilometers of Europa’s surface. It used a special instrument called the Microwave Radiometer (MWR) to study the moon.
What Is the Microwave Radiometer?
The Microwave Radiometer (MWR) is designed to measure microwave energy. Normally, it studies Jupiter’s atmosphere. But during a moon flyby, it can also scan below the surface of icy moons.
The MWR has six antennas that measure microwave signals at different frequencies:
| Frequency (GHz) | Purpose |
|---|---|
| 0.6 GHz | Deep surface measurement |
| 1.2 GHz | Ice temperature check |
| 2.4 GHz | Surface structure scan |
| 4.8 GHz | Mid-layer ice study |
| 9.6 GHz | Shallow ice analysis |
| 22 GHz | Surface detail check |
These signals helped scientists “see” below Europa’s ice shell and measure temperature at different depths.
How Thick Is Europa’s Ice Shell?
The new data shows that Europa’s outer ice shell is about 29 kilometers (18 miles) thick on average.
This measurement mainly refers to the cold and rigid outer layer made of pure water ice. However, scientists believe there might be a slightly warmer and softer layer underneath. If that is true, the total ice thickness could be even more.
If the ice contains salt, the thickness might be about three miles less than estimated. But overall, the data supports the thick ice shell model.
Why Does Ice Thickness Matter?
The thickness of Europa’s ice shell is very important for understanding habitability.
If the ice is very thick:
- Oxygen and nutrients from the surface will take longer to reach the ocean.
- It becomes harder for materials to move between the surface and the ocean.
- Life, if it exists, would have fewer ways to get energy from the surface.
If the ice were thin:
- There could be easier pathways for materials to reach the ocean.
- Conditions might be better for life.
The new findings suggest the ice is thick, meaning any exchange between surface and ocean would be slow and difficult.
What About Cracks and Pores in the Ice?
The MWR data also found small irregular features in the ice. These include:
- Cracks
- Pores
- Voids
These features scatter microwave signals, similar to how ice cubes scatter light. Scientists call them “scatterers.”
Some experts previously thought these cracks might reach deep enough to connect the surface to the ocean. But the new research shows that these features do not go deep enough to touch the subsurface ocean.
So, they are not direct pathways to the ocean.
How Does This Help Future Missions?
Two major missions are on the way to study Jupiter’s moons:
- Europa Clipper (launched October 2024)
- Jupiter Icy Moons Explorer (JUICE, launched April 2023 by the European Space Agency)
Europa Clipper will focus mainly on Europa and check whether its ocean can support life. JUICE will study Europa, Ganymede, and Callisto.
The new ice thickness data from Juno will help these missions plan:
- Where to collect data
- Which areas to observe closely
- How to design future experiments
This makes Juno’s findings extremely valuable.
Current Status of Juno Mission
Juno completed its second mission extension in September 2025 but continues to fly by Jupiter. Its recent flyby happened on January 23, and its 81st flyby is scheduled for February 25.
Even after many years in space, Juno is still sending useful data to Earth.
The latest findings from NASA’s Juno spacecraft have given scientists a clearer picture of Europa’s icy surface. The discovery that Europa’s ice shell is around 29 kilometers thick supports the thick ice model. This means that if life exists in Europa’s hidden ocean, it may be well protected under a deep layer of ice.
However, the thick shell also makes it harder for nutrients and oxygen to travel between the surface and the ocean. The research is a big step forward in understanding Europa’s habitability.
With future missions like Europa Clipper and JUICE on the way, we may soon learn even more about this mysterious moon and its chances of supporting life beyond Earth.
FAQs
Why is Europa important for space scientists?
Europa is important because it has a large ocean under its ice. Water is necessary for life, so scientists believe Europa could support life.
How thick is Europa’s ice shell?
The ice shell is about 29 kilometers (18 miles) thick on average, according to new data from NASA’s Juno spacecraft.
Can cracks in the ice connect to the ocean?
No, the new study shows that cracks and pores do not reach deep enough to connect to the subsurface ocean.