But if you didn’t already know, I’m honored to tell you that Neptune also has rings. They’re just much fancier and therefore extremely difficult to see without high-powered telescopes. The planet itself, in fact, is 30 times farther from the sun than Earth is and appears to standard stargazing instruments as nothing more than a faint speck of light. Despite our inability to admire Neptune’s fragile rings from here, scientists got a wonderful glimpse of them inhabiting the blue realm in 1989 thanks to NASA’s Voyager probe — and on Wednesday, the agency’s equally excellent James Webb Space Telescope introduced us to the second round. “It’s been three decades since we last saw these faint, dusty rings, and this is the first time we’ve seen them in the infrared,” said Heidi Hammel, a Neptune system specialist and interdisciplinary scientist for JWST. “Webb’s extremely stable and precise image quality allows these very faint rings to be detected so close to Neptune.” And as if that weren’t enough, this new image features Neptune, sure to give off a soft lavender glow under JWST’s near-infrared lens, against a backdrop of galaxies adeptly accommodating the same piece of next-generation space technology. It is clear evidence that JWST is too sensitive to capture what we might consider “empty space.” This machine is powerful enough to literally open a treasure box every time it stares into space. Without further ado, Neptune: In this image from Webb’s Near-Infrared Camera (NIRCam), a cluster of hundreds of background galaxies, varying in size and shape, appear alongside the Neptune system. Officially registered on July 12, 2022. ESA Of every image JWST has taken so far, this is simply my favorite. Its depth of field gives me existential butterflies because it’s disconcerting to see a planet full, rings included, floating only in front of deceptively small galaxies that are, in reality, hundreds of thousands of light years across. These galaxies are gigantic distances from our solar system’s cosmic neighborhood (home to our own Neptune), yet they carry many more cosmic neighborhoods. For comparison, see what Voyager recorded of Neptune’s rings in 1989. NASA, JPL
Breaking JWST’s lens on Neptune
The brilliant luminescence seen in JWST’s portrait of Neptune exists only because it is filtered by the telescope’s infrared powers. We examine an imaging of invisible, infrared wavelengths emitted by the gaseous world. We’re not looking at the visible wavelengths we’re used to — the ones that show us color, like the kind the Hubble Space Telescope works with, for example. Neptune still has its characteristic blue hue that comes from elements on the planet, such as methane gas, but JWST can’t show them to us. That’s not what it was built to do. The Hubble Space Telescope shows Neptune in its blue glory while tracking two dark storms on the planet. The larger one is towards the center top and the smaller one is towards the right. NASA, ESA, STScI, MH Wong (University of California, Berkeley) and LA Sromovsky and PM Fry (University of Wisconsin-Madison) “In fact, methane gas absorbs so strongly that the planet is quite dark at Webb wavelengths,” the European Space Agency said in a press release, “Except where there are high-altitude clouds. Such methane ice clouds are visible as bright streaks and spots, reflecting sunlight before it is absorbed by methane gas.” You can further see a thin line of brightness circling the planet’s equator, which the team says may indicate the global atmospheric circulation associated with Neptune’s winds and storms. “The atmosphere descends and warms at the equator, so it shines at infrared wavelengths more than the surrounding, cooler gases,” NASA said. At the north pole, the agency says, there is also a “fascinating brightness” and at the south pole, further evidence of a vortex on the globe’s surface. Last but certainly not least, of Neptune’s 14 known moons, JWST caught seven: Galatea, Naiad, Thalassa, Despina, Protea, Larissa, and Triton. Showing off JWST’s signature six-pronged glow, Triton can be seen on its strange backward orbit, offering astronomers hope that JWST can help decipher the strange situation. JWST captured seven of Neptune’s moons. NASA, ESA, CSA and STScI “Dominating this Webb portrait of Neptune is a very bright point of light with the characteristic diffraction spikes seen in many of the Webb images,” ESA said. “It’s not a star, but Neptune’s most unusual moon, Triton.” However, it’s the context of the image that really moves me. If we zoom out from Triton and those dusty rings of Neptune and those mysteries of the polar vortex, it becomes obvious that we can see these cosmic details only by sheer coincidence of existence in this iota of the universe.
