Europa has some Unusual Spikes on its Surface

Europa has some Unusual Spikes on its Surface

50-meter high structures of ice await spacecraft that want to land on the surface of Europa.

Despite being the 6th largest moon of our solar system, Europa is the smallest of the four Galilean moons of Jupiter. The name of this moon came from Europa, the legendary mother of King Minos of Crete. It was discovered in 1610 by Galileo Galilei alongside three other moons of the largest planet of our solar system. Scientists believe that it probably has an iron-nickel core while most of its crust is made up of water and ice. Similarly, silicate rocks are extremely abundant in the composition of Europa. It has an incredibly thin atmosphere composed primarily of Oxygen. Although there are several cracks and streaks on its surface, craters are extremely rare on this moon.

The smoothness of its surface made astronomers believe that it could harbor extraterrestrial life because it may have an ocean of water underneath its surface. A lot of theories were presented to show the possibility of life on Europa but the most dominant among all suggests that ‘Tidal Flexing’ generates the necessary heat to keep the ocean in a liquid state. In addition to that, it drives ice movement on the surface of the moon similar to what ‘Plate Tectonics’ do on Earth. The detection of ‘water vapor plumes’ by the Hubble Space Telescope strengthened this idea. Until now, no spacecraft has landed on the surface of Europa but a lot of efforts are being made to accomplish this feat. However, it will not be an easy mission to execute as a recent study added to the difficulties of the space agencies.

The paper published in the journal ‘Nature Science’ reported that Europa might have (significant chances) a protective shield of 50-foot ice blades (penitentes) that could destroy any landing spacecraft. Europa has all the ideal conditions for generating penitentes like cold and dry conditions. Likewise, lack of atmosphere and being tidally locked to its parent planet makes the production of penitentes even more likely. Sublimation of the icy surface is the process which leads to all these spiked formations. The heat from the Sun sublimes some of the ice which leaves behind ice that gets carved into strange shapes.

A massive question that arises here is that is it possible for these structures to survive in the airless atmosphere of Europa? Processes like Meteorite Strikes and Space Weathering can destroy these penitentes over a long period of time but the latest research shows that the rate of sublimation is much more than the erosion caused by space weathering. The authors of the study clarified the issue in the following words:

Surface sublimation rates exceed those of erosion by space weathering processes in Europa’s equatorial belt (latitudes below 23°), and that conditions would favor Penitente growth. Puzzling properties of the radar and thermal observations of Europa’s equatorial belt can be explained by the presence of penitente fields in this region.”

Astronomers haven’t managed to get a direct glimpse of these penitentes as none of the cameras that captured Europa were sensitive-enough to confirm whether these spikes actually exist at the equator or not. For this reason, the researching team took help from the radar evidence which voted in favor of their predictions. In the past, radar beams were fired at all the moons and planets of our solar system. The behavior of these beams was recorded when they returned back to Earth after bouncing from these celestial objects.

The beams from Europa revealed that they struck an even number of surfaces before reflecting away. This was a strange thing as it didn’t happen with any other major object of our solar system. At that time, scientists couldn’t understand the reason for that but they do have an explanation now. They used these gigantic penitentes on the moon to explain that effect. The radar beams who had wavelengths smaller than the gaps between the spikes bounced an even number of times before coming back to Earth.

Europa is not the first non-Earth object where these structures are observed. Prior to that, the New Horizons Mission found ‘Methane ice’ penitentes on Pluto which helped in explaining the bladed terrain of the minor planet.

Computer Scientist by qualification who loves to read, write, eat, and travel

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