Portal:Jupiter/Astronomy/5

Planetary astronomy
"Jupiter takes 12 years to make one trip around the Sun. These 12 images [on top] were taken between 2003 and 2015. At far left we see Jupiter in 2003, and the years proceed counterclockwise. The 2015 view is immediately above 2003."

"Jupiter’s axial tilt is just 3° or nearly straight up and down, so seasons don’t exist. One part of the Jovian year is much the same as another. Still, as you can plainly see, the solar system’s biggest planet has plenty of weather."

"Just look at the Great Red Spot or GRS. Through about 2008, it’s relatively large and pale but suddenly darkens in 2010 at the same time the South Equatorial Cloud Belt (the wide stripe of clouds above the Spot) disappears. If you look closely at the Spot from year to year, you’ll see another big change — it’s shrinking! The GRS has been dwindling for several decades, but it’s amazing how obvious the difference is in only a dozen years."

"The planet gives off 1.6 times as much energy as it get from the Sun."

"Fun to think that the light we see from Jupiter is reflected sunlight, but if we could view it with heat-sensing, infrared eyes, it would glow like an ember."

"Images [second down] in the visible-light and infrared parts of the spectrum highlight the massive changes roiling the atmosphere of Jupiter. In the visible-light images on the left that were obtained by amateur astronomers, Jupiter can be seen "losing" a brown-colored belt south of the equator called the South Equatorial Belt (SEB) from 2009 to 2010. This belt returned in 2011 and was still present in 2012. From 2011 to January 2012, a belt north of the equator known as the North Equatorial Belt (NEB) can be seen to be thinning out. In 2011, it whitened to an extent not seen in over a century. In March of 2012, after the last picture in this series was taken, the northern belt began to darken again."

"Scientists compared the visible-light data to data obtained in infrared wavelengths (middle and right columns), which show progressively deeper levels in the Jovian atmosphere. The infrared images were obtained from NASA's Infrared Telescope Facility on Mauna Kea, Hawaii, except for the 2011 image in the 8.7-micron wavelength (right column, third from the top), which was taken by the Subaru Telescope, also in Mauna Kea, Hawaii. Those data showed a thickening of the deeper cloud decks in the northern belt during that time, and a partial thickening of the upper cloud deck. The South Equatorial Belt saw both levels of clouds thicken and then clear up. The infrared data also resolved brown elongated features in the whitened area of the North Equatorial Belt known as "brown barges" as distinct features and revealed them to be regions clearer of clouds and probably characterized by downwelling, dry air."

"Also visible in the infrared observations are a series of blue-gray features that are the clearest and driest regions on the planet and show up as apparent hotspots in the infrared view because they reveal the radiation emerging from a very deep layer of Jupiter's atmosphere. Those hotspots disappeared from 2010 to 2011, but had reestablished themselves by June of this year, coincident with the whitening and re-darkening of the North Equatorial Belt."