NASA's James Webb Telescope to now unravel mysteries of Jupiter's Great Red Spot

**NASA's** James Webb Space Telescope will use its unparalleled infrared capabilities to study **Jupiter's** Great Red Spot, shedding new light on the enigmatic storm, the US space agency said. Led by Leigh Fletcher, a senior research fellow from the University of Leicester, the scientists plan to use Webb’s mid-infrared instrument (MIRI) to create multispectral maps of the Great Red Spot and analyse its thermal, chemical and cloud structures. They will be able to observe infrared wavelengths that could shed light on what causes the spot’s iconic colour. The colour has often been attributed to the sun’s ultraviolet radiation interacting with nitrogen, sulfur and phosphorus-bearing chemicals that are lifted from Jupiter’s deeper atmosphere by powerful atmospheric currents within the storm. Fletcher explained that using MIRI to observe in the 5 to 7 micrometer range could be particularly revealing for the Great Red Spot, as observations in such wavelengths are not possible from Earth.

Those wavelengths of light could allow the scientists to see unique chemical byproducts of the storm, which would give insight into its composition. “We’ll be looking for signatures of any chemical compounds that are unique to the (Great Red Spot) … which could be responsible for the red chromophores,” Fletcher noted. Chromophores are the parts of molecules responsible for their colour. Webb’s observations may also help determine whether the Great Red Spot is generating heat and releasing it into Jupiter’s upper atmosphere, a phenomenon that could explain the high temperatures in that region. Generations of astronomers have studied the Great Red Spot; the storm has been monitored since 1830, but it has possibly existed for more than 350 years. The reason for the storm’s longevity largely remains a mystery, and Fletcher explained that the key to understanding the formation of storms on Jupiter is to witness their full life cycle — growing, shrinking, and eventually dying. We did not see the Great Red Spot form, and it may not die anytime soon (though it has been shrinking, as documented by images from NASA’s Hubble Space Telescope and other observatories), so scientists must rely on observing “smaller and fresher” storms on the planet to see how they begin and evolve, something that Webb may do in the future, said Fletcher.