Since it’s recently been discovered that there’s a vast ocean beneath the surface of Earth, which is comprised of about three times more water than all our oceans combined, I thought we could take a tour of some possible extraterrestrial oceans that may exist beyond our world. Climb aboard the “Ocean Express” with me, and we’ll head to the closest possibility faster than the speed of light.
First stop on our underground ocean search is Mars. ESA’s Mars Express spacecraft recently spotted sediments on Mars’ northern plains similar to those found on an ocean floor, in a area previously identified as the site of an ancient Martian shoreline. Scientist involved with the Icarus study discovered evidence of a massive underground ocean of about 93,000 cubic kilometers, an amount slightly larger than that of all the surface-level fresh water on Earth. There is speculation that just one cataclysmic event allowed that water to escape and cover the Martian surface for a time before it evaporated or seeped back inside again.
Next stop, Europa, the planet known for it’s watery surface. It’s a fairly well-accepted fact that beneath the icy surface, this moon’s interior is a vast ocean. Astronomers don’t even think it would take a great deal of effort to drill down into the surface to find this water. Also, since they believe the ocean bubbles up to that surface, it’s possible all they’d need to do was simply scrape a sample from the top to discover what lies beneath.
By now the view must be spectacular as our ship leaves the first gas giant behind to seek a moon near the second. Enceladus is thought to house a vast ocean under its surface as well. Deep beneath the area covered in “tiger stripes” lies relatively warm waters. These waters are probably quite warm, and this helps contribute to the periodic, sudden burst of water that emits from its surface.
Farther out into the vastness of space, we approach the moon Ariel, a satellite that circles Uranus. Much like Enceladus this moon’s surface appears free of markings, with only a few craters and flow-like features that suggest ice-volcanos of old. The ocean here, if it exists, would be kept liquid from the gravitational tug of other moons there, and the vast amount of rock surrounding it would also generate heat.
In keeping with the lunar visits, next we’re off to Neptune’s most popular moon, Triton. The surface of this moon would be quite frigid. Back in 1989 Voyager 2 discovered the surface was made up primarily of water ice. However, researchers from the University of Maryland suggest between the layer of ice and rock, a hidden ocean might be present. It’s been speculated that ammonia in the liquid would lower its freezing point and thus keeps it from freezing solid.
And finally, the end of the trip, we approach Charon. Quite recently scientists have hypothesized that the surface of Charon is riddled with cracks, which might suggest it once had an underground ocean. It is so cold out in the depths of space where Charon floats, the surface temperature is estimated to be about 380 degrees below 0 degrees Fahrenheit. This means Pluto and Charon and the other, newly discovered moons out there cannot possibly have liquid water on their surfaces. Scientist believe the surface of Charon will be very much like Enceladus or Europa’s, where the exterior enables the insides to stay nice and warm. However, until we reach Charon next year in reality and have a look at its surface, this remains speculation only.
With so many possible oceans to choose from in our own solar system, it would be quite interesting if we could take the “Ocean Express” a bit further out. One can only imagine how many other worlds might contain underground oceans of their own.