NASA’s Juno spacecraft flew past Io on 30 December and took one of our best pictures yet of this moon of Jupiter
By Alex Wilkins
2 January 2024
This image of Io was captured by the Juno spacecraft
NASA/SwRI/MSSS
We have just had our closest look at Jupiter’s volcanic moon Io for decades, thanks to NASA’s Juno spacecraft, which passed the moon on 30 December.
Juno, which has been orbiting Jupiter since 2016, has been taking increasingly close images of Io in recent months as its path around Jupiter changes.
This latest image was taken just 1500 kilometres above the moon’s surface. In it, some of Io’s hundreds of towering mountains are visible, which can reach more than 10 kilometres tall, as well as their long, sharp shadows.
Advertisement
Read more
Stunning photo of a young star hints how Jupiter-like planets form
Io is thought to be the most volcanically active body in the solar system and has hundreds of active volcanoes. These volcanoes tend to be smaller than the largest mountains, averaging only 1 or 2 kilometres in height, and are harder to make out in the image.
However, by comparing images and data from Juno’s previous 56 flybys of the moon, astronomers can learn about how these volcanoes have varied over time and why they are so active.