We wouldn't be making great progress if we had to rely solely on satellites to learn about the outer planets. It takes a lot of effort to get a craft to the outer Solar System. Thanks to the Hubble Space Telescope, we can keep an eye on the gas giants.
NASA keeps an eye on the outer planets to monitor their atmospheres. Hubble checks in yearly to see how Jupiter, Neptune, and other gas/ice giants are doing, because changes on Jupiter, Neptune, and other gas/ice giants take place on timescales of years and decades. Scientists get a baseline of data. OPAL will continue until either Hubble is no longer operational or the WFC3/UVIS camera is no longer functioning.
The planet Jupiter.
People who don't follow astronomy know that Jupiter is a big ball of gas with a beautiful atmosphere. Do they not? The Great Red Spot has its own page on the internet. This year's Hubble image of Jupiter shows the planet's atmosphere to the fullest.
The planet Jupiter was seen by Hubble on September 4th, 2021. The OPAL team is made up of M.H. Wong and A. Simon from the Goddard Space Flight Center.
The OPAL team was interested in the colour of the planet. It has a deep orange hue. The deep orange is still a surprise even though the region is no longer in that scheme.
Ammonia is the most visible substance in the upper atmosphere. Light bands are called zones, while dark bands are called belts. The zones are colder than the belts. The belts are moving. The zones are lighter in colour because of ammonia ice.
There are two Hubble OPAL images of Jupiter. The left and right images are from 2020. There is a small white spot below the GRS in 2020. Scientists were surprised by the orange hue of the equatorial zone. The moon in 2020 is called Europa. The OPAL team is made up of M. H. Wong and the University of California, Berkeley.
Scientists call the storm cells that are shown in the 2021, image barges. They are rotating counterclockwise. There are cyclonic storms south of the equator.
This image shows a different view of Jupiter. It shows a wave structure just north of the equator. The image is from the Wikimedia Commons, CC BY 4.0.
There is a planet called Saturn.
Jupiter has an atmosphere that is visually interesting. The beautiful rings of Saturn have their own page on the internet.
The new look at the planet shows a rapid and extreme colour change in the northern hemisphere, where it is now early autumn. The bands have changed over time in Hubble observations. The blue-ish hue of the south pole is visible in Hubble's image of the planet.
Though not as pronounced as Jupiter, the bands of Saturn are changing and not fully understood. Powerful storms with wind speeds reaching 1800 km/hour are what they signify. OPAL images do not show a storm at the north pole. The hexagonal storm has its own page on the internet.
There are two Hubble OPAL images, one on the left and one on the right. The rapid and extreme color changes in the northern hemisphere are caused by hydrocarbons in the atmosphere and increased summer heating. The OPAL team is made up of M.H. Wong and A. Simon from the Goddard Space Flight Center.
Every image of Saturn has the rings prominently featured. Christian Huygens was the first to identify them as a disk. They are mostly made of water ice, ranging in size from tiny grains to boulders. Astronomers are unsure of their age and the exact mechanism that formed them is not fully understood. They are thought to be from the Solar System's early days, while data from Cassini suggests they are young.
The image is made up of 141 wide angle images and is backlit by the Sun. At 4 o'clock, the dim dot is Earth. The Day-the-Earth-Smiled is a NASA image.
The planet Uranus.
Hubble images aren't as sharp as they are for Jupiter and Saturn, and Uranus is an awfully long way away. Jupiter and Saturn are gas giants, while Uranus and Neptune are ice giants. It is possible to track changes in the planet's upper atmosphere.
The bright northern polar hood of the planet is in the spotlight thanks to Hubble. The OPAL team is made up of M.H. Wong and A. Simon from the Goddard Space Flight Center.
This image was taken in the northern hemisphere. Scientists think that increased UV radiation from the Sun is making the polar region brighter. The ice giants have more methane than the gas giants, and the increased UV may be making the methane more opaque. There could be something else happening with the aerosol particles.
Over the last several years of OPAL observations, one thing is constant. The southernmost boundary stays at the same latitude even as the atmospheric hood gets brighter. It is possible that a jetstream enforces that barrier.
It is strange that a planet with an almost 90 degree angle of rotation is called Uranus. The planet has strange seasons compared to Earth. Each season is 21 years long because it takes 84 Earth years to complete. The seasons of Uranus are due to the planet's tilt, which is nearly circular around the Sun.
Neptune is a planet.
Neptune is dark rather than red. The spot has its own page on the internet. Astronomers have been watching it. It is not one dark spot, but a recurring series of storms that change every few years. Jupiter's GRS has been around for hundreds of years.
The OPAL program took this Hubble image in September of 2021. There is a dark spot on the south pole. The OPAL team is made up of M.H. Wong and A. Simon from the Goddard Space Flight Center.
The OPAL team has been watching Neptune for a long time. The dark spot, which is a storm the size of the Atlantic Ocean, is moving south towards destruction. The spot was shown reversing course in 2020. The Hubble has been watching storms on Neptune for 30 years, but has never seen this before. Hubble has seen four dark spot storms since 1993, all of which followed a straight path to the equator.
There are two OPAL images of Neptune, one on the left and one on the right. There is a small dark storm to the right of the Great Dark Spot in the 2020 image. The OPAL team is made up of M.H. Wong and A. Simon from the Goddard Space Flight Center.
Neptune is an ice giant, unlike a gas giant. The blue appearance of methane is due to the higher percentage of methane in the atmosphere.