These images show different views of a volcanic eruption on Jupiter’s moon, Io.
The image at top was taken by the New Horizons spacecraft as it made its closest approach to Jupiter on its long journey to Pluto. The close-up image, taken when the spacecraft was just 1.5 million miles (2.5 kilometers) away, reveals sharp details of Io’s surface. The volcanic plume is 180 miles (290 kilometers) high. Io, one of Jupiter’s largest moons, has the most active volcanoes in the solar system.
The two images at the bottom were taken by Hubble, which was the first telescope to spy the volcanic outburst. The image at left shows the moon as we would see it if we could travel there. The image at right was taken in ultraviolet light to capture the volcanic material streaming into space.
The Hubble images of Io do not show as much detail because the telescope is much farther away from the moon than New Horizons. The Earth-orbiting telescope is about 500 million miles (800 million kilometers) from Io, nearly 500 times farther away from the moon than New Horizons was when it snapped its image.