The James Webb
space telescope has once again turned its powerful gaze away from the deep
universe towards our solar system, capturing an incredible image of a
ghostly Neptune and its elusive, dusty rings in detail not seen for decades.
Webb recently revealed Jupiter at its best in a series of fresh photos,
And now it has set its sights on the last major planet in the solar system.
Neptune has fascinated researchers since its discovery in 1846, yet the only spacecraft to
have ever visited the distant planet was NASA's Voyager 2 during a flyby in 1989.
One of the reasons the ice giant has not been visited since is because of how far away it is.
Neptune is located 30 times farther from the Sun than Earth, lurking in the remote,
dark region of the outer solar system. At that extreme distance, the Sun is so small and faint
that high noon on Neptune is similar to a dim twilight on Earth. In fact, it takes sunlight
over 4 hours to reach Neptune, whereas it takes just over 8 minutes to reach Earth. So it's
been three decades since we last saw Neptune's rings in this much stunning detail and clarity.
The Hubble space telescope has captured many incredible images of Neptune over the years,
revealing signs of the planet's atmosphere and sometimes even its mysterious moons. However,
this latest image from Webb reveals much more because the powerful telescope observes
in the infrared spectrum, a type of light that is invisible to our eyes.
In the visible spectrum Neptune appears as a blue orb in front of a black background,
but when we look at it in infrared many more incredible features come
into view. So what can we see in Webb's latest image of the ice giant Neptune?
Firstly you will have noticed that Neptune doesn't appear to be blue like it is when
seen in images from Hubble for example. This is because the methane gas in its atmosphere strongly
absorbs red and infrared light making Neptune appear much darker than Webb's image. However,
we can see high-altitude methane ice clouds, in the form of bright streaks and spots. This
is because the high-altitude clouds reflect the sunlight before it is absorbed by the methane gas.
Because of Neptune's tilt and long 164-year journey around the sun,
its north pole, at the top of the planet, is just out of view. But if you look closely,
you can see that it is much brighter, indicating something intriguing is occurring in this region.
More subtly, a thin line of brightness circling the planet’s equator could
be a visual signature of global atmospheric circulation that powers Neptune’s strong winds
and storms. When Voyager 2 passed Neptune it discovered a highly active atmosphere,
with wind speeds far exceeding 680 miles per hour,
which is about 1,100 kilometres an hour. The fastest winds ever detected in the solar system.
Most striking about Webb’s new image is the crisp view of the planet’s dynamic rings,
some of which haven’t been seen at all, let alone with this clarity, since Voyager 2 passed by all
those years ago. When we think of Neptune, bright rings circling the planet don't come to mind. In
visible light, Neptune's rings are difficult to see because they are dark and vary in density and
size. But in this stunning image, we can see them in all their glory. They are made up of dust and
rocks and may have formed relatively recently when one of Neptune's moons was destroyed.
We can, however, still see many of Neptune's existing moons, and Webb captured seven of the 14
known to orbit the ice giant. These are Galatea, Naiad, Thalassa, Despina, Proteus, Larissa, plus
one more that might not be quite as obvious, as a moon anyway. Looming over Neptune a bright spiky
star can be seen, but this isn't a star, this is Triton, Neptune's largest and strangest moon.
Like Neptune, the only close-up images of Triton came from Voyager two as it swung past in 1989.
The flyby revealed a geologically young surface, active geysers spewing icy material out from its
frozen crust and a vast south polar cap with a pinkish hue. Covered in nitrogen frost and
tholins, which are dark organic compounds, Triton is one of the coldest places ever to be visited.
At first glance Triton may seem like a fairly regular large moon orbiting
a distant giant Planet, however, this is not the case, this strange world is anything but normal.
The large moons of the solar system, such as Earths moon and all of the major moons of Jupiter,
Saturn and Uranus orbit roughly the same plane as their planet and they orbit in the same direction
as their planet rotates, which is counterclockwise if you are looking from above. But Triton does
not follow any of these properties. Instead, the bizarre world orbits in the opposite direction to
Neptune's rotation and follows a highly inclined 157-degree path, relative to Neptune's Equator.
This unusual orbit, which is called a retrograde orbit suggests that Triton
had a very different history, compared to the regular large moons of the solar system.
Causing scientists to wonder whether Triton was instead plucked from another region of space,
possibly the Kuiper belt, as it shares a lot of similarities with dwarf planets such as Pluto.
The reason Triton looks so bright in Webb’s image is because the unusual moon is covered
with a frozen sheen of condensed nitrogen which reflects 70 percent of the sunlight
that hits it. It far outshines Neptune in this image because the planet’s atmosphere
is darkened by methane absorption at these near-infrared wavelengths.
Behind Neptune and its moons, just like in other incredible James Webb space telescope images,
a smattering of hundreds of galaxies can also be seen many of which have likely never been
observed before. The one that stands out the most, however, sits towards the bottom left
of this image, a barred spiral galaxy. Scientists say this particular galaxy,
previously unexplored in detail, may be about a billion light-years away
and is dominated by young stars that appear blueish in these wavelengths.
This latest image from Webb is just the first of many when it comes to
observing our solar system. The telescope will continue observing both Neptune and
triton in the coming years. Yet with its first look, Webb has revealed things that could only
be seen in this much clarity and detail by actually visiting the distant planet. Once
again showcasing Webb's powerful gaze on a universe that is full of mystery.
I hope you enjoyed this video, if you did please tap the like button and consider subscribing,
it really does help to support my channel. Thank
you so much for watching and I'll see you all next time.