It’s always exciting when scientists find something in space that is familiar to us on our planet. That’s just what happened recently when data brought back from the Hubble Telescope has revealed that the ocean on Jupiter’s moon Europa could be filled with sodium chloride (NaCl), just like our own oceans. Otherwise known as table salt, it’s the same thing that has been found in kitchens and sprinkled on food for centuries. The discovery of it on Europa might mean that Jupiter’s moon is more similar to Earth than experts first thought.

How the possibility of table salt on Europa was first noticed

Over two decades ago, scientists first began to suspect that sodium chloride, rather than sulfate salts, were the dominant salt in Europa’s enormous oceans. At that time, NASA’s Galileo spacecraft detected some yellowish patches on the moon’s surface. Subsequent experiments back on Earth demonstrated that these patches could, in fact, consist of table salt.

Help from the Hubble telescope

The initial findings from Galileo prompted deeper research from the Hubble telescope which sent back photos from between May and August of 2017. Scientists only found it because they switched the techniques they were using to look at the pictures from a spectrometer containing the visible spectrum on light to a spectrometer containing only infrared light rays. As they were analyzed back on Earth by scientists from Caltech and from NASA’s Jet Propulsion Laboratory in Pasadena, the analysis showed definite signs of table salt.These signs were proven to match a lab-generated sample from 2017 that was created in an environment similar to Europa.

Interestingly, these signs weren’t entirely where experts expected them to be. They were concentrated on the sections of the moon that faces Jupiter and on younger areas of the moon where substances from Europa’s oceans may be reaching the surface. The scientists determined it was likely–though not certain–the salt was part of the interior of the moon.

What the discovery means

One thing that the discovery means is that science’s understanding of both Europa’s surface and internal composition will have to change and that Europa may be more interesting to scientists than first thought. It is exciting to consider that a major extraterrestrial object might be more like our planet than anyone has ever thought. This discovery also shows the value in analyzing in using new techniques and analyzing areas deeper in an extraterrestrial body as opposed to focusing on a planet or moon’s surface only.

Further observation is warranted

It is worth noting that there is a possibility that the table salt could have come from an icy shell that covers the ocean, rather than from the water itself. For this reason, and to continue to improve on our understanding of the moon, further examination is warranted. Scientists will be re-reviewing past data with an eye towards certifying what they think they’ve found. In addition, a specific, Europa-focused mission will launch at some point in the 2020s and will likely make approximately 45 passes at the moon to gather more information. The results of that effort should be astonishing.

Could Europa support life?

This recent discovery is also raising the possibility that Europa could support life. Scientists aren’t sure whether it is true or not, but the presence of the same substances in Europa’s oceans that was in our oceans, where our planet’s life evolved from, is exciting. It encourages a possibility that, until now, had existed almost exclusively in the minds of science fiction writers. Scientists will certainly keep exploring Europa and are open to the possibilities to find things they never would have expected to see previously.