There’s nothing like a Hubble photo of Jupiter. This sweet image was made on June 27 and features the planet’s turbulent pastel cloud belts and iconic Great Red Spot (GRS). The bands or belts are created by differences in the thickness and height of Jupiter’s ammonia ice clouds. The flow in opposite directions at various latitudes, a result of different atmospheric pressures. Lighter bands rise higher and have thicker clouds than the darker bands — together they alternate like the tooth-and-gap profile of a gear.
Watch a full rotation of Jupiter in Hubble images
One of the most striking features this year are the parallel, ruddy-brown cloud stripes moving toward the GRS. Among the most striking features in the image are the rich colors of the clouds moving toward the Great Red Spot, a giant storm cell similar to a hurricane (but 1.3 times the diameter of Earth) rolling counterclockwise between two bands of clouds.
All of Jupiter’s colorful cloud bands in this image are confined to the north and south by jet streams that remain constant, even when the bands change color. The bands are all separated by winds that can reach speeds of up to 400 miles (644 km) per hour, while the swirling filaments seen around the outer edge of the red super storm are high-altitude clouds that are being pulled in and around it.
The Great Red Spot is a towering structure shaped like a wedding cake, whose upper haze layer extends more than 3 miles (5 km) higher than clouds in other areas. The gigantic structure, with a diameter slightly larger than Earth’s, is a high-pressure wind system called an anticyclone that has been slowly shrinking since the late 1800s. Why remains unknown.
Jupiter is fascinating no matter what instrument you use — eye, binoculars (you can see up to four of it moons) or telescopes. Tonight, the waxing gibbous moon will snuggle right up close to the planet in a striking conjunction. If the sky at your location is even just partly clear, take a look up during evening twilight or later at night before 11:30 and you’ll love the sight.
Finally, amateur astronomer Ethan Chappel of Texas almost certainly recorded an impact flash in Jupiter’s South Equatorial Cloud belt this past Wednesday night (Aug. 7). The brief flash lasted about a second and was likely produced when a comet or asteroid struck the planet. If confirmed it will be the 7th such impact spotted in recent years. For the deets and more photos, check out my Sky & Telescope article here.