While NASA’s Juno spacecraft continues to capture previously unseen views of Jupiter from its polar orbit, this Hubble portrait of the gas giant shows a more familiar perspective, yet with amazing clarity.

Up-to-date images of Jupiter like this one are revealing something intriguing about the gas giant: its Great Red Spot is shrinking.

This huge anticyclonic storm spans a distance 1.3 times Earth’s diameter and has been observed by astronomers for centuries.

It is currently not clear what’s causing the spot to decrease in size, but studies using both Hubble and Juno provide vital clues that may help planetary scientists find an answer.

What’s also striking about this image is the detail in the numerous bands that create Jupiter’s stripy appearance.

These are generated by air in the planet’s stormy atmosphere flowing in opposite directions at different latitudes, dictated by the thickness and height of ammonia ice clouds.

The bands are kept separate by fast winds that can reach speeds of up to 650 kilometres per hour.

This image was captured when Jupiter was 644 million kilometres from Earth.


Iain Todd BBC Sky at Night Magazine
Iain ToddScience journalist

Iain Todd is BBC Sky at Night Magazine's Content Editor. He fell in love with the night sky when he caught his first glimpse of Orion, aged 10.