A new scientific observation made from afar appears to give researchers another reason to want to explore Jupiter's moon Europa firsthand.

According to Time, authors of a study published in the journal Geophysical Research Letters revealed a mysterious material on the moon's surface to be sea salt from its subsurface oceans. Past studies have already suggested the real possibility of those subsurface oceans and following studies have explored them further.

"We have many questions about Europa, the most important and most difficult to answer being is there life? Research like this is important because it focuses on questions we can definitively answer, like whether or not Europa is inhabitable," Curt Niebur, Outer Planets Program scientist at NASA Headquarters in Washington, said in a press release. "Once we have those answers, we can tackle the bigger question about life in the ocean beneath Europa's ice shell."

Now it might soon be time to send a spacecraft to Europa to deliver an aquatic robot to test the waters in the manner NASA has done so with its Mars rovers. Scientists at Cornell University designed a robotic eel to one day send to Europa to literally test the moon's waters.

"If the concept eventually succeeds, it will enable amphibious exploration of gas-giant moons, notably Europa. It likely is relevant to other moons of Jupiter and Saturn with liquid lakes or oceans," reads a description of the robot on NASA's website. "Juno's success notwithstanding, solar power near Jupiter is very limited. Furthermore, the recent cancellation of SMD's ASRG technology motivates alternatives to nuclear power. The bio-inspired technologies we propose to consider bypass the need to power rovers with limited-lifetime batteries, large solar arrays, or nuclear power."

As Time noted, Europa manages to keep its icy exterior with liquid water beneath with tidal flexing, which occurs when gravitational force from Jupiter's other large moons pass by and help generate internal heat. The gravitational pull also creates surface cracks, which result in geysers.