Why is Jupiter changing color?

A small telescope reveals the mesmerizing light and dark bands that run parallel to Jupiter's equator, resulting from ammonia clouds driven by powerful high-altitude currents. The cause behind the color difference remains uncertain, but it seems to be associated with the transformation of ammonia from gas to ice. However, within each band, color variations occur in long cycles, which scientists have struggled to explain.

Recent observations from NASA's Juno mission suggest that Jupiter's magnetic field may be responsible for these color variations. Researchers from the University of Leeds have discovered that the planet's torsional oscillations, or changes in its magnetic field, coincide with periods of infrared radiation variation . This breakthrough could help us understand the mysterious color-changing phenomena on Jupiter.

Jupiter's powerful easterly and westerly winds create the alternating bands of light and dark that we see on the planet's surface. According to Chris Jones, a co-author of the research, these winds change direction every four or five years, leading to global upheavals in the planet's cloud structures. The movement of Jupiter's Great Blue Spot has also been observed to slow down, possibly signaling the beginning of a new oscillation.

However, much uncertainty remains regarding the exact mechanism through which torsional oscillations produce the observed infrared variation. Kumiko Hori, the study's author, hopes that their research will open new doors for exploring Jupiter's deep interior, similar to how seismology and helioseismology have allowed us to study Earth and the Sun, respectively.