Uranus (Nov. 2014 and Nov. 2022)

Uranus (Nov. 2014 and Nov. 2022)

Planetary oddball Uranus rolls on its side around the Sun as it follows an 84-year orbit, rather than spinning in a more-vertical position as Earth does. Uranus has a weirdly tipped "horizontal" rotation axis angled just eight degrees off the plane of the planet's orbit. One recent theory proposes that Uranus once had a massive moon that gravitationally destabilized it and then crashed into it. Other possibilities include giant impacts during planetary formation, or even giant planets exerting resonant torques on each other over time. The consequences of the planet's tilt are that for stretches of time lasting up to 42 years, parts of one hemisphere are completely without sunlight. When the Voyager 2 spacecraft visited during the 1980s, the planet's south pole was pointed almost directly at the Sun. Hubble's latest view shows the northern pole now tipping toward the Sun.

[left]—This is a Hubble view of Uranus taken in 2014, seven years after northern spring equinox when the Sun was shining directly over the planet's equator, and shows one of the first images from the OPAL program. Multiple storms with methane ice-crystal clouds appear at mid-northern latitudes above the planet's cyan-tinted lower atmosphere. Hubble photographed the ring system edge-on in 2007, but the rings are seen starting to open up seven years later in this view. At this time, the planet had multiple small storms and even some faint cloud bands.

[right]—As seen in 2022, Uranus' north pole shows a thickened photochemical haze that looks similar to the smog over cities. Several little storms can be seen near the edge of the polar haze boundary. Hubble has been tracking the size and brightness of the north polar cap and it continues to get brighter year after year. Astronomers are disentangling multiple effects—from atmospheric circulation, particle properties, and chemical processes—that control how the atmospheric polar cap changes with the seasons. At the Uranian equinox in 2007, neither pole was particularly bright. As northern summer solstice approaches in 2028 the cap may grow brighter still, and will be aimed directly toward Earth, allowing good views of the rings and north pole; the ring system will then appear face-on. This image was taken on November 10, 2022.

Credits

Science

NASA, ESA, STScI, Amy Simon (NASA-GSFC), Michael H. Wong (UC Berkeley)

Image Processing

Joseph DePasquale (STScI)

About The Object
Object Name Uranus
Object Description Planet
Distance On Nov. 09, 2014 Uranus was 19.18 AU (1.78 billion miles). On Nov. 14, 2022 Uranus was 18.68 AU (1.74 billion miles).
About The Data
Data Description The HST observations include those from programs , and (A. Simon)
Instrument WFC3/UVIS
Exposure Dates 09 Nov. 2014, and 09 Nov. 2022
Filters F467M, F547M, and F845M
About The Image
Color Info These images are a composite of separate exposures acquired by the WFC3 instrument on the Hubble Space Telescope. Several filters were used to sample medium wavelength ranges. The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter. In this case, the assigned colors are: Blue: F467M, Green: F547M, Red: F845M
Compass Image Two views of Uranus appear side-by-side for comparison. At the top, left corner of the left panel is the label Uranus. At the bottom, center of the left image is the label 2014, and at the bottom, center of the right image is the label 2022. Set against a black background, the Uranus appears in the center of each panel. The planet appears tipped on its side. Uranus is mainly colored cyan. In both views, the planet looks like a flat circle outlined with a pinkish gray limb. In the left view from 2014, faint, pinkish gray bands and streaks run nearly vertically across Uranus, while splotches of white clouds dot the right half of the planet’s face. The right third of the planet appears mostly white and pinkish gray, as though that part of the atmosphere were thick with clouds. A faint, pink ring encircles the planet nearly vertically. In the right image from 2022, the faint, pink ring appears to be almost face on. A large area of white coves much of the right side of the planet.
About The Object
Object Name A name or catalog number that astronomers use to identify an astronomical object.
Object Description The type of astronomical object.
R.A. Position Right ascension – analogous to longitude – is one component of an object's position.
Dec. Position Declination – analogous to latitude – is one component of an object's position.
Constellation One of 88 recognized regions of the celestial sphere in which the object appears.
Distance The physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs.
Dimensions The physical size of the object or the apparent angle it subtends on the sky.
About The Data
Data Description
  • Proposal: A description of the observations, their scientific justification, and the links to the data available in the science archive.
  • Science Team: The astronomers who planned the observations and analyzed the data. "PI" refers to the Principal Investigator.
Instrument The science instrument used to produce the data.
Exposure Dates The date(s) that the telescope made its observations and the total exposure time.
Filters The camera filters that were used in the science observations.
About The Image
Image Credit The primary individuals and institutions responsible for the content.
Publication Date The date and time the release content became public.
Color Info A brief description of the methods used to convert telescope data into the color image being presented.
Orientation The rotation of the image on the sky with respect to the north pole of the celestial sphere.

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