NASA’s New Horizons spacecraft zipped past Jupiter and caught this image of Io, the planet’s third-largest moon, as a volcano was erupting on the surface. The plume emanating from the Tvashtar volcano is 200 miles high.
The image was created by NASA's Visualization Explorer and we saw it tweeted by Katie Mack (@astrokatie).
Here's NASA's description of the image:
Locked in a perpetual tug of war between the imposing gravity of Jupiter and the smaller, consistent pulls of its neighboring moons, Io’s distorted orbit causes it to flex as it swoops around the gas giant. The stretching causes friction and intense heat in Io’s interior, sparking massive eruptions across its surface.
Here's a GIF of the explosion in action:
At 2,263 miles in diameter, Io is slightly larger than Earth’s moon. According to NASA, it is the most volcanically active body in the solar system.
Here's another image of the moon's dynamic surface. The black spots are collapsed volcanoes: 