News Archive for April 2025 | Sci.News

The image columns show the change of Uranus for the four years that Hubble’s STIS instrument observed Uranus across a 20-year period. Over that span of time, astronomers watched the seasons of Uranus as the south polar region (left) darkened going into winter shadow while the north polar region (right) brightened as it began to come into a more direct view as northern summer approaches. The top row, in visible light, shows how the color of Uranus appears to the human eye as seen through even an amateur telescope. In the second row, the false-color image of the planet is assembled from visible and near-infrared light observations. The color and brightness correspond to the amounts of methane and aerosols. Both of these quantities could not be distinguished before STIS was first aimed at Uranus in 2002. Generally, green areas indicate less methane than blue areas, and red areas show no methane. The red areas are at the limb, where the stratosphere of Uranus is almost completely devoid of methane. The two bottom rows show the latitude structure of aerosols and methane inferred from 1,000 different wavelengths (colors) from visible to near infrared. In the third row, bright areas indicate cloudier conditions, while the dark areas represent clearer conditions. In the fourth row, bright areas indicate depleted methane, while dark areas show the full amount of methane. At middle and low latitudes, aerosols and methane depletion have their own latitudinal structure that mostly did not change much over the two decades of observation. However, in the polar regions, aerosols and methane depletion behave very differently. In the third row, the aerosols near the north pole display a dramatic increase, showing up as very dark during early northern spring, turning very bright in recent years. Aerosols also seem to disappear at the left limb as the solar radiation disappeared. This is evidence that solar radiation changes the aerosol haze in the atmosphere of Uranus. On the other hand, methane depletion seems to stay quite high in both polar regions throughout the observing period. Image credit: NASA / ESA / Erich Karkoschka, LPL.

Hubble Sheds New Light on Atmospheric Composition and Dynamics of Uranus

Apr 1, 2025 by News Staff

A 20-year Hubble study of Uranus provide valuable data for understanding the atmospheric dynamics of this distant ice giant, which can serve as a proxy...

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