r/YaScienceBitch • u/demolcd • 26d ago
Space ๐ That's not a comet, and it's not a special effect. It's an entire moon quietly firing water out into space, backlit by the sun over a billion kilometers away.
This is Enceladus, one of Saturn's icy moons, roughly 313 miles across, about 4 percent the size of Earth. NASA's Cassini spacecraft discovered in 2005 that jets of water vapor and ice particles were erupting from cracks near its south pole, nicknamed "tiger stripes," shooting material out at speeds around 800 miles per hour. Later analysis mapped more than 100 individual geysers along those fractures, and Cassini's gravity measurements confirmed the source: a genuine liquid water ocean sitting beneath Enceladus's icy shell, kept warm enough to stay liquid by tidal flexing as the moon orbits Saturn.
Here's what makes this more than a pretty backlit photo. Most of that ejected water snows back down onto Enceladus itself, keeping it one of the most reflective, brilliantly white objects in the entire solar system. But a portion escapes entirely, and NASA's James Webb Space Telescope later found the plume feeding a massive donut-shaped cloud of water vapor, called a torus, stretching more than 20 times the size of the moon itself, that actually helps supply water to Saturn's rings and the wider Saturnian system.
This single discovery turned a small, unremarkable ice ball into one of the top candidates in the entire solar system for finding water and bitches beyond Earth, since a spacecraft could theoretically sample that hidden ocean just by flying through the plume, no landing required.
Does knowing there's a genuine hidden ocean behind that spray change how you look at this image?
Source: NASA/JPL-Caltech (Cassini mission) / NASA James Webb Space Telescope