Jupiter Section Blog
Jupiter Update & Observing Opportunities
10/26/2025
Jupiter’s Great Red Spot (GRS) remains a striking feature in the planet’s southern hemisphere, now measuring approximately 10,250 miles (16,500 km) across. Despite this being its smallest recorded size, the ongoing red color makes it a higher-contrast object that can be discerned visually by skilled observers in instruments as small as 90mm. Recent Hubble and ground-based data reveal a 90-day oscillation cycle, where the GRS subtly expands and contracts. Given the possible conclusion of the Juno mission and competition for time on the Hubble, amateur observations are increasingly valuable in monitoring these fluctuations (along with edge “flaking” and internal vorticity changes).
Jupiter Map Oct 1, 2025
Expert amateur imager Damian Peach’s latest overview notes the GRS’s strong coloration and its interaction with a weak, patchy South Tropical Band. The South Temperate Belt (STB) is especially active, split into two dark sectors – the most extensive it’s been in decades. Segment A lies south of the GRS and Segment G is centered at approximately System III longitude of 180°). The STB has also had a recent eruption just trailing the GRS that is worth watching. Oval BA remains subtle and low contrast in white light, though its center has gained a little orangish color that may be visible in high-resolution amateur captures.
The North Equatorial Belt (NEB) is beginning its periodic recession, and the North North Temperate Belt (NNTB) shows reddish oblong features of interest. And lets not overlook the South Equatorial Disturbance (SED) within Jupiter’s South Equatorial Belt (SEB), roughly centered near System II longitude ~150°–180°. Observers have noted its persistence and visibility, especially in methane-band imaging, where it appears as a bright plume-like feature.
What you can help document through your sketches and image captures:
  • GRS size fluctuations: Crisp images when the GRS is on or near the meridian can help document its size.
  • GRS edge activity: Larger instruments can watch for flaking or detachment of cloud fragments.
  • GRS Color changes: Capture subtle shifts in hue during expansion phases.
  • Oval BA structure: Will it perk back up or continue to languish as a harder to see feature?
  • STB and NNTB features: Track belt segmentation and oblong formations as well as the recent eruption there.
  • Monitor the SED in methane band: Capturing the SED’s morphology and tracking its drift across longitudes could be a valuable contribution.
With the 2025-2026 Jupiter apparition in full swing, observers using 6–14" scopes and lucky imaging techniques can contribute valuable data. Even 4" scopes can resolve the GRS as a pale reddish oval. ALPO encourages submissions of your image and sketches (following our guidelines to help ensure that they are scientifically useful) to Jupiter@alpo-astronomy.org for review by the section coordinator and posting in our image gallery. Remember – your observations help shape our understanding of Jupiter’s dynamic atmosphere!
Supporting the Juno Mission
9/26/2025
Roughly every 33 days Juno sweeps by Jupiter (i.e., perijove) in a mad dash to capture high-resolution data of the planet’s dynamic atmosphere. But JunoCam, the spacecraft’s visible-light camera, can’t monitor Jupiter continuously. That’s where amateur observations from our members can be helpful.
Ground-based images taken before, during, and after perijove provide crucial context. They help scientists track evolving features like the Great Red Spot, convective outbreaks (such as the recent new outbreak in the South Temperate Belt captured by ALPO member Gary Walker), and jet stream activity. These images can even influence which regions JunoCam targets during its next flyby.
NASA actively encourages amateurs to submit their processed Jupiter images to the JunoCam image gallery, where they may be used in outreach materials, scientific presentations, and publications—with full credit given. Of course, we strongly encourage all ALPO members to submit these observations for upload in our image repository by sending them to Jupiter@alpo-astronomy.org.
To maximize impact, observers should aim to image Jupiter within ±2 days of a scheduled perijove (see table below). Using filters such as methane band or infrared can reveal high-altitude clouds and auroral features. Be sure to follow our guidelines designed to maintain the scientific value of the report.

Perijove Observations Window

October 17-20

November 18-22

December 19-22
Jupiter Observing Alert
1/11/2025
NTB Outbreak
Clyde Foster's capture of the outbreak in methane light on January 10, 2025 at 18:56 UT
Clyde Foster and Manos Kardasis have just (Jan 10UT) imaged a bright spot in the NTBs jet region. This is likely the beginning of a major outbreak. John Rogers of the B.A.A. says, "We can expect it to become spectacular!"
It is brightest in the methane band, but should brighten in other wavelengths as it develops. It should create a a dark turbulent wake in the next few days.
Initial position is SYS 1 longitude of 168° with a drift of around -5° per day. (Note: the fast current travels at SYS 1 speed despite being at a latitude of around +26°.)
All observers are encouraged to monitor Jupiter as much as possible. There should be several more outbreaks at other longitudes in the coming days.
Send your images to jupiter@alpo-astronomy.org, following the Image Submission Guidelines so that your image will be searchable in the database.
Feel free to post your images to the ALPO Jupiter Section Groups.IO as well which can be found here.
Clear Skies,
Craig MacDougal
Assistant Coordinator
ALPO Jupiter Section
Jupiter 2024-25 Apparition Underway
8/27/2024

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.

BAA Issues Report on EZ
1/30/2022

Dr. John Rogers at the British Astronomical Association has announced publication of their 7th report for the 2021-2022 apparition of Jupiter. This report highlight activity in Jupiter’s Equatorial region.

  •  Methane-bright patches in the EZ that are almost stationary in their CM III (L3) longitude
  • Bright plume outbreaks seen in the unusually quiet NEBs with two recent outbreaks happening December 19th and January 9th.