Jupiter’s moon Europa has been the subject of intense study ever since the Voyager probes sent back images of its cracked, icy surface. There’s a strong possibility Europa has a subsurface liquid ocean. Some observations have shown geysers erupting from the moon, but we haven’t been able to verify there was water there until now. NASA’s Goddard Space Flight Center confirms water vapor bursting forth from the moon’s surface.
Europa is the smallest of the “Galilean” moons — those discovered by Galileo in the 17th century. It wasn’t until the 20th century that we got our first close-up view of the moon, and we were in for a surprise. Europa is covered in “lineae,” the reddish streaks featuring prominently in all the images you’ve seen of the moon. Scientists believe these are cracks in the moon’s icy crust, through which water leaks out and re-freezes. The constant remodeling of the surface means Europa is the smoothest object in the solar system with no mountains or plateaus visible. Although, it might have icy spikes around the equator.
Past observations from the Hubble telescope have shown liquid plumes erupting from Europa, similar to what we see on Saturn’s moon Enceladus. If Europa has a liquid water ocean under all that ice, you’d naturally expect the geyser to consist of water. Europa isn’t as active as Enceladus, but researchers scanned the planet 17 times between February 2016 and May 2017 hoping to catch sight of water. On one day, April 26, 2016, the W. M. Keck Observatory in Hawaii spotted the spectral fingerprint of water vapor rising above Europa. The detection was around 2,000 metric tons of water, which is enough to fill an Olympic-sized swimming pool.
The confirmation of water vapor around Europa is important, but the team notes that there may be less water escaping from the moon than expected. Plumes may be rare and highly localized, suggesting that few large breaches open in the ice layer. The only way to know for sure what’s going on is to study Europa up close.
NASA plans to move forward with the Europa Clipper mission in 2025, which will be the first important planetary mission launched with the Space Launch System (SLS). Europa Clipper will conduct 45 flybys of the moon, using a suite of cameras, spectrometers, and radar to unravel the mysteries of this celestial body. If Europa does have a reservoir of liquid water inside, there’s a chance it could also host alien life.
- NASA Says Evidence of Life on Europa Could Be Under a Few Inches of Ice
- NASA Moves Forward With Europa Clipper Mission
- Enceladus, Not Europa, Could Be the Best Place to Search for Extraterrestrial Life