Free Astronomy Magazine November-December 2020

34 NOVEMBER-DECEMBER 2020 SPACE CHRONICLES by NASA/ESA T his latest image of Jupiter, taken by the NASA/ESA Hubble Space Telescope on 25 August 2020, was captured when the planet was 653 million kilome- tres from Earth. Hubble’s sharp view is giving researchers an updated weather report on the monster planet’s tur- bulent atmosphere, including a remarkable new storm brewing, and a cousin of the Great Red Spot changing colour — again. The new image also features Jupiter’s icy moon Europa. A unique and exciting detail of Hubble’s new snapshot appears at mid-northern latitudes as a bright, white, stretched-out storm moving at 560 kilometres per hour. This single plume erupted on 18 August 2020 and an- other has since appeared. While it’s common for storms to pop up in this region, often several at once, this particular disturbance appears to have more structure behind it than observed in previ- ous storms. Trailing behind the plume are small, coun- terclockwise dark clumps also not witnessed in the past. Researchers speculate this may be the beginning of a longer-lasting northern hemisphere spot, perhaps to rival the legendary Great Red Spot that dominates the southern hemisphere. Hubble shows that the Great Red Spot, rolling counterclockwise in the planet’s southern hemisphere, is ploughing into the clouds ahead of it, forming a cascade of white and beige ribbons. The Great Red Spot is currently an exceptionally rich red colour, with its core and outermost band appearing deeper red. Researchers say the Great Red Spot now measures about 15,800 kilometres across, big enough to swal- low the Earth. The super- storm is still shrinking, as noted in telescopic observa- tions dating back to 1930, but its rate of shrinkage ap- pears to have slowed. The rea- son for its dwindling size is a complete mystery. Researchers are noticing that an- other feature has changed: the Oval BA, nicknamed by astronomers as Red Spot Jr., which appears just below the Great Red Spot in this image. For the past few years, Red Spot Jr. has been fading in colour to its original shade of white after appearing red in 2006. However, now the core of this storm appears to be darkening to a reddish hue. This could hint that Red Spot Jr. is on its way to reverting to a colour more similar to that of its cousin. Hubble’s image shows that Jupiter is clearing out its higher-altitude white clouds, especially along the planet’s equator, which is enveloped in an orangish hy- drocarbon smog. Hubble captures crisp new image of Jupiter and Europa