One possible explanation is that the Hubble observations were more sensitive to the perpetual dark
nightside of the planet where the atmosphere is slightly colder and the photochemical mechanisms that destroy methane are less efficient than on the dayside.
This area of Saturn was actually on
the nightside of the planet when photographed, but it had rotated into daylight by the time Cassini met its fiery end there.
However, the distribution of material from the dayside to
the nightside of a planet is only likely to occur on worlds with a high surface gravity.
The nightside of the planet is actually quite hot.
Not exact matches
This will reveal both the signatures
of atmospheric ingredients such as water, methane, and carbon dioxide, and also how heat flows from the planet's dayside to its
nightside.
The team's measurements suggest the planet's
nightside would actually exhibit a ruddy glow because its temperature appears to be in excess
of 1,000 degrees Celsius — as hot as a blast furnace.
Assuming Proxima b is tidally locked, Webb could then detect changes in the planet's thermal glow as its cold,
nightside and warm, sunlit dayside shift in and out
of view across one complete orbit, rather like watching phases
of the moon as it circles Earth.
The dayside
of a planet close to an M dwarf, however, might become so hot that water escapes to space; on the frigid
nightside, the atmosphere could freeze to the surface.
A key finding
of this research indicates that there is still no clear understanding
of how the material that is moving from the hot dayside
of the planet onto the cold
nightside both cools and alters it chemical composition.
Twice the size
of Jupiter, KELT - 9b is likely to be tidally locked, with a scorching dayside always facing the star and a cooler
nightside facing away.
The haze scatters sunlight into the
nightside, teasing researchers with glimpses
of odd landforms faintly illuminated in Pluto's twilight.
Because planet b is tidally locked and the outer atmosphere is so efficient at re-radiating heat, its «
nightside» stays dark and cold (top), unlike bands
of even temperature on a Jupiter - like planet (shown below — more).
The spacecraft, which arrived at Mars on Sept. 21, 2014, has images from the
nightside and the dayside
of the planet.
AOES Medialab, ESA Alternative, larger and jumbo illustrations
of hydroxyl in Venus»
nightside by ESA and C. Carreau.
A tenuous, thin layer
of ozone has been detected high in Venus» atmosphere that probably forms in its
nightside (more).
The JWST will have a mirror 6.5 metres (21.3 feet) in diameter, seven times larger than that
of the HST, and will orbit the Sun in a Lissajous pattern around the second Lagrangian point, about 1.5 million km (930,000 miles) from Earth on the planet's
nightside.
Grant talks about there being a «
nightside» to the tree
of life, functioning as a «mirror image»
of its «dayside».
In the colour - coded image, which simultaneously shows dayside and
nightside auroral activity, the most intense levels
of activity are red, and the lowest levels are blue.
From solar influence weighting to %
of white ground cover to when are clouds on the dayside VS lack
of clouds on the
nightside, we have miles to go before gaining a good understanding
of cause and effect with climatology.