If Jupiter's moon Europa has geysers, the natural engines that power them are well-hidden.
Scientists have re-examined data from NASA's Galileo mission in greater detail in search of regions on Europa warm enough to be linked to plumes of water vapor. If hotspots exist on this moon—which harbors a huge ocean of liquid water beneath its icy shell—they will most likely remain hidden until NASA's Europa Clipper spacecraft arrives at Jupiter in the late 2020s or early 2030s, the researchers determined.
In 2016, scientists announced the provisional detection of a faint plume on Europa using NASA's Hubble Space Telescope. A second unconfirmed plume was announced the following year. Since then, the moon has remained quiet, and scientists have debated whether the features spotted by the space telescope were actually caused by wafting water vapor. [Possible Water Plumes on Europa: The Discovery in Images]
In an effort to solve the mystery, Julie Rathbun and her colleagues turned to data collected by Galileo when it orbited Jupiter in the 1990s and early 2000s. Rathbun is a senior scientist at the Planetary Science Institute in Tucson, Arizona. The researchers had searched the moon for heat signals almost a decade ago, before the potential plumes were spotted. Now, they returned to examine the two potential source regions more closely, looking for signs of heat that might indicate geological activity. The results were less than encouraging.
To read more, click here.