Jupiter has a long history of surprising scientists – all the way back to 1610 when Galileo Galilei found the first moons beyond Earth. That discovery changed the way we see the universe. Jupiter is, by far, the largest planet in the solar system – more than twice as massive as all the other planets combined.
Jupiter's familiar stripes and swirls are actually cold, windy clouds of ammonia and water, floating in an atmosphere of hydrogen and helium. Jupiter’s iconic Great Red Spot is a giant storm bigger than Earth that has raged for hundreds of years.
Jupiter Blog
The 2024-2025 Jupiter apparition is well underway now, heading for western quadrature on September 12th when it will lie on the meridian at sunrise. Early morning observers have been submitting reports and excellent images, documenting the current belt and zone activity.
The Great Red Spot retains an orangish color and is down to about 13,100 km as measured in a recent fine image by ALPO member Gary Walker. With Earth’s equatorial diameter at 12,750 km, we have to wonder how much longer the most iconic storm in our solar system can claim to be larger than our home planet!
The South Equatorial Belt region trailing the GRS is fairly turbulent, with a large rift running SE-NW appearing the last couple of weeks. As noted by John Rogers and Shinji Mizumoto in their recent BAA report for the start of the apparition, there is an interesting South Equatorial Disturbance on the northern edge of the SEB, at about L1 = 280°. The North Equatorial Belt is back to being the widest, most dominant belt on the planet, making some of the long-enduring white spots (e.g., WS-E, WS-Z) more easily seen against the brown backdrop of the belt. There also have been some very intense “hot spots” along the southern border of the NEB, appearing as dark slate color.
Please continue to send in your images and sketches to jupiter@alpo-astronomy.org following the guidelines for submitting reports.
Jupiter News Headlines
Jupiter's Turbulent GRS
10/9/2024
The Hubble
Space Telescope focused on Jupiter's iconic Great Red Spot for the first
three months of this year. The scientists found that the storm is jiggling
like gelatin, squeezing in and out at the same time as it moves faster and
slower. UV observations also demonstrated that the core is brightest when
the spot is at its greatest size during the oscillations.
Read More
GRS Age in Dispute
6/19/2024
A new study published in Geophysical Research Letters suggests that Jupiter’s Great Red Spot we observe today has been around for about 190 years and is not the same feature observed by famed astronomer Giovanni Domenico Cassini in 1665. The authors used historical sources dating from the mid-1600s to analyze the evolution of the spot's size, structure and location over time. Their study also postulates some mechanisms that could have given rise to the Solar System’s most iconic super storm.
Read More
Event Calendar
Dec 07, 2024
Jupiter at opposition
Mar 02, 2025
Jupiter at eastern quadrature