So-called “brown barges” are cyclonic storms in Jupiter’s atmosphere that are typically found in the giant planet’s relatively dark North Equatorial Belt but they are occasionally spotted om the South Equatorial Belt as well. The storms are difficult to detect visually because they tend to blend in with the surrounding areas. But occasionally, the darker material in the belt recedes and brown barges become easier to see against the lighter background. This image, capturing a brown barge in the South Equatorial Belt, was captured by NASA’s Juno Jupiter orbiter on 6 September as the probe made its 15th close flyby at a distance of 11,950 kilometres (7,425 miles) from Jupiter’s cloudtops. The color-enhanced JunoCam image was processed by citizen-scientist Kevin M. Gill.
In the early evening of Tuesday, 23 February, the rising waning gibbous Moon — one day after full Moon — lies just 3½ degrees from magnitude -2.5 planet Jupiter low in the eastern sky. Jupiter is closest to Earth on Tuesday, 8 March, so now is the time to get acquainted with the solar system’s largest planet.
UK observers with a clear sky an hour before sunrise on Friday 28 October should look very low in the east-southeast to see the slim crescent of the 27-day-old Moon less than four lunar diameters away from largest planet Jupiter. The Moon and Jupiter are also joined by third-magnitude double star gamma (γ) Virginis, commonly known as Porrima.
A team of scientists has documented atmospheric changes on Io, Jupiter’s volcanically active satellite, as the giant planet casts its shadow over the moon during daily eclipses. Io’s thin atmosphere collapses as the sulfur dioxide gas emitted from volcanoes freezes when shaded by Jupiter. The atmosphere reforms when Io moves out of eclipse and the ice sublimates.