120-The Outer Planets: Hubble’s Continuing Legacy
February 10, 2025
The NASA/ESA Hubble Space Telescope has completed its annual grand tour of the outer Solar System for 2021. This is the realm of the giant planets — Jupiter, Saturn, Uranus, and Neptune — extending as far as 30 times the distance between Earth and the Sun. Unlike the rocky terrestrial planets like Earth and Mars that huddle close to the Sun’s warmth, these far-flung worlds are mostly composed of chilly gaseous soups of hydrogen, helium, ammonia, and methane around a packed, intensely hot, compact core.
What is OPAL?
OPAL (Outer Planet Atmospheres Legacy) is a project to obtain long time baseline observations of the outer planets in order to understand their atmospheric dynamics and evolution as gas giants.
The yearly observations from OPAL throughout the remainder of Hubble’s operation will provide an important legacy of time-domain images for use by planetary scientists.
Viewers might notice that some of the images of the same planets appear to be different colors. This is due to the fact that over the years, from Voyager to Hubble, many different instruments, and many different filters have been used.