2023-05-09 18:40:17
In its particular tour of the planets of the solar system, the James Webb Space Telescope has delighted us with snapshots such as the rings of Jupiter, the methane clouds in Neptune’s atmosphere and even the craters and volcanoes on the Martian relief. And even so, he still has much more to give us.
It is true that its main task is the study of the primitive universe (ver further) as well as the chemical composition of the so-called extrasolar planets. However, that does not imply that the data collected by James Webb about our neighboring planets is not important.
Recently, the Webb has focused on another of our ice giants: the planet Uranus. In a awesome catch Taken on February 6, 2023, its rings, a polar cap and six of its satellites can be seen with maximum clarity.
However, and before commenting on these new images, let’s get to know this unique gas giant a little better.
colder than neptune
Uranus is a unique planet in many respects, from the length of its seasons (related to its peculiar lateral rotation) to its extreme temperatures (it is the coldest planet in the solar system).
NASA
Discovered in 1781 by the astronomer William Herschel, Uranus describes one orbit around the Sun in 84 years. The duration of Your day It is about 17 hours and 14 minutes. Although its mass is 14 and a half times that of Earth, it is the least massive giant planet.
Composed primarily of water, ammonia, and methane, its atmosphere contains hydrogen and helium (as well as methane, which gives it its typical cyan-blue color).
It is the coldest planet in the solar system: it reaches average temperatures of -218 ℃ and minimum temperatures of about -226 ℃. The reason for these low records is that Uranus has a much cooler inner core than other planets. In addition, it absorbs less heat than it receives from the Sun. In this last aspect, its peculiar lateral rotation also has a lot to do with it.
Only planet that rotates laterally
Uranus does not rotate like a top around the Sun (as we could visualize the rest of the planets): its axis of rotation is so inclined that it resembles a ball running.
In the animation below, we can compare the tilt of each planet’s axes of rotation with relative to the ecliptic.
The most accepted theory about this anomalous rotation suggests the collision of a massive object (of at least twice the Earth’s mass) against the young planet Uranus that caused a drastic change in its axis of rotation.
As a consequence of this lateral rotation, the seasons do not change until the north and south poles slowly reverse their position. These poles present 42 years of uninterrupted sunlight, followed by another 42 years of total darkness.
This is how James Webb shows us Uranus
With only 12 minutes of exposure (and using two infrared filters at 1.4 and 3 microns), the James Webb Space Telescope has surprised us with this snapshot of the planet Uranus.
NASA, ESA, CSA, STScI. Image processing: J. DePasquale (STScI)
In the image above we can distinguish the following details about this frozen giant:
1. The amazing ring system
By showing 11 of Uranus’s 13 known rings, Webb again demonstrates unprecedented resolution in detecting the faintest rings.
In this sense, only the Voyager 2 spacecraft (when it flew over the planet in 1986) and the Keck ground observatory (using advanced adaptive optics) have been able to image Uranus’s faintest rings.
2. The north polar cap
You can also see a wide bright region located in the north polar cap of Uranus. It only appears in direct summer sunlight and disappears in the fall.
It seems that this region increases in size the more amount of sunlight it receives. This is a phenomenon not yet explained by scientists and it is believed that James Webb will help to better understand it.
3. Bright clouds and stormy activity
Bright clouds can be seen in Uranus’s atmosphere both at the edge of the polar cap and at the far left of the upper snapshot.
These clouds are visible in the infrared range (precisely the wavelength at which Webb operates) and are believed to be related to intense storm activity in its atmosphere.
NASA, ESA, CSA, STScI. Image processing: J. DePasquale (STScI)
On the other hand, the previous image corresponds to an enlarged view of the system that surrounds Uranus. In it, it is possible to differentiate in detail 6 of its 27 known moons: Miranda, Ariel, Umbriel, Titania, Oberón and the Puck indoor satellite (all of them with their typical star shape characteristic of James Webb).
And the rest of Uranus’ satellites? They do not appear in the image above because they are too small to be seen with such a short exposure time.
In the background of the image, a handful of galaxies completes this impressive mosaic.
The importance of these new images
According to the United States National Academies of Sciences, Engineering, and Medicinethe study of the planet Uranus has been declared a priority in its Astrobiology and Planetary Science survey for the period 2023-2033.
Not surprisingly, NASA plans to send a mission to this gas giant in 2031 that will study, among other details, its composition, atmosphere and magnetosphere.
In this sense, the James Webb can play a fundamental role in the observation of this frozen world, capturing images with a higher resolution than the previous ones (which, let’s remember, were registered with only 12 minutes of exposure).
In the meantime, let’s continue to delight ourselves with the impressive images of this unique planet in the solar system, the only one that orbits the Sun… on its side.
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