Five things about NASA’s Juno probe
1 THE POLES
Jupiter is a gas giant, 1,000 times the size of Earth, and its orbit means its equatorial regions are visible by telescope from Earth, but its poles cannot be seen. You just have to go there, as the Pioneer 11 spacecraft did in 1974. But Juno has far better cameras. It launched from Florida in 2011 and arrived in its orbit last summer, an elliptical circuit that brings it close to the planet once every 53 days.
2 POWERFUL STORMS
Some of the most exciting images are of the atmospheric storms known as the string of pearls. These eight storms are each smaller than the Great Red Spot, a giant storm that has been rotating for at least 150 years, but they seem to be more dynamic. Over the last 30 years, their number has varied from as few as six to as many as nine.
3 MORE THAN JUST WEATHER
Juno — named for the mythical daughter of Saturn, consort of Jupiter, and mother of Mars — has eight scientific instruments to collect data about Jupiter’s gravity, atmosphere and electromagnetic fields and radiation, with a focus on the glowing auroras.
4 TROUBLE ALOFT
The spacecraft’s orbit was supposed to be brought much closer by a planned engine burn in October, but a problem with valves meant those plans were scrapped. It will stay in its longer orbit until next year, when it will be sent hurtling into Jupiter’s atmosphere of hydrogen and helium, and then into its liquid interior, never to return.
5 RECONSTRUCTED ON EARTH
Most images from satellites are not ready for publication. Their colour and contrast needs to be reconstructed, adjusted and enhanced. NASA has posted the raw images from its JunoCam on the Internet, and invited the public to add their own colour enhancements, or crop them to highlight a particular feature of the atmosphere.