Have you been following how the hues in Saturn’s southern hemisphere have been changing? It is always a bit subjective to gauge the true color of the planet, but clearly observers’ images show the frosty blue giving way as the southern hemisphere emerges from its winter.

Christophe Pellier, an avid planetary astronomer who maintains the excellent Planetary Astronomy website, has published his analysis of photometry and imaging of Saturn from the 2023 apparition that provides insight and some scientific measurement as to the colors of the planet and how they are changing as we move towards the equinox next year. You can find his discussion, analysis, and images here.

In two weeks Saturn will come to opposition, and with it an opportunity to witness the “Seeliger Effect” (or Opposition Surge). Named for German astronomer Hugo von Seeliger who first noticed in 1887 the brightening of the rings within roughly a day of opposition. This brightening of the rings is discernable in amateur telescopes, but to appreciate it you should take in the appearance of the rings several days ahead of opposition to better appreciate the change.

What causes this phenomenon? Scientists believe that “coherent backscattering” is responsible. The direct illumination of the rings from Earth’s perspective at opposition reflects off the irregular particles of the rings to produce a single, more intense light. As a result, if you catch the Seeliger Effect you are seeing evidence that the rings are made up of irregular particles rather than a solid body as was once thought.