First-Ever Images of Neptune's Eerie Glow Finally Reveal Missing Aurora
The most elusive planetary aurora in the Solar System has finally been revealed in all its gently glowing glory.
Far from the Sun, and Earth, the sky-blue planet Neptune has been captured shimmering in near-infrared light as particles interact in its hazy atmosphere.
It's the first time an aurora has been imaged on the Solar System's outermost known planet, thanks to the sensitivity of JWST's powerful near-infrared spectrometer.
At last, the set is complete. Auroras have been seen on every single planet in the Solar System, revealing that the phenomenon is not just widespread, but a feature of the interaction between planets and the Sun.
The phenomenon does, however, look very different depending on the world on which it appears. Earth's auroras are the most spectacular, a panoply of colors that light up the sky when particles from the solar wind slam into Earth's magnetic field, where they rain down into the upper atmosphere.
The interaction between these incoming particles and the atmosphere's resident particles causes dancing, glowing lights.
Jupiter has the most powerful, energetic auroras in the Solar System, permanent caps of bright ultraviolet light. Actually, its four largest moons have auroras, too. Saturn likewise has ultraviolet auroras, as does Mars. Venus has green auroras, much like those seen on Earth.
Mercury's aurora is, perhaps, the strangest; because it has no atmosphere, the aurora manifests as X-ray fluorescence from the interaction between solar particles and minerals on the surface.
For a long time, it was unclear what auroral activity, if any, might be present on Uranus and Neptune, so far from the Sun: Uranus orbits at around 19 times the distance between the Sun and Earth, and Neptune at around 30 times.
In 2023, an analysis of archival data confirmed the presence of infrared auroras at the Uranian equator. Now, JWST data has proven the existence of similar auroras at Neptune.
In 2023, the space telescope obtained a detailed spectrum of Neptune's atmosphere, revealing the clear presence of the trihydrogen cation (H3+) – a positively charged form of trihydrogen associated with auroras.
By tracking the concentration of H3+ across the skies of Neptune, a team of astronomers led by Henrik Melin of Northumbria University in the UK was able to map the location of the planet's auroras.
Interestingly, a quirk of Neptune's magnetic field meant that its auroras were not where they would appear here on Earth. The lines of our planet's magnetic field converge around the poles; when solar particles are whisked away and dumped into the atmosphere, high latitudes are the focal point of the dumping.
Neptune and Uranus both have very messy, lopsided magnetic fields. On Neptune, the dumping point for solar particles is near the planet's equator, rather than the poles.
JWST measurements of the temperature of the distant ice giant also revealed why we've had such a hard time detecting Neptune's auroras. Temperatures of Neptune reported by Voyager 2 measurements – the only human-made spacecraft to have ever neared the planet – were much higher than those detected by JWST, suggesting the planet has cooled significantly since 1989.
Colder temperatures mean fainter auroras. Previous predictions about Neptune's possible auroras were based on inaccurate temperatures, so scientists had been looking for the wrong thing.
This discovery gives us a new tool to interpret, not just the variety that can be exhibited by a single phenomenon across very different worlds here in the Solar System, but also on other worlds orbiting alien stars.
"Since the most commonly detected type of extrasolar planet is Neptune-sized, and as Neptune lacks the extreme seasons of Uranus," the researchers write in their paper, "these observations provide a new diagnostic to probe atmosphere-magnetosphere interactions on the most common-sized worlds in our galaxy."
The research has been published in Nature Astronomy.
Toxic Mars Dust Could Pose Major Health Risks For Future Astronauts
Stunning Swirl in Europe's Skies Caused by Classified Space X Mission
Supermoon This Week Will Coincide With Rare 'Devil Horns' Solar Eclipse
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Yahoo
an hour ago
- Yahoo
Odds of asteroid 2024 YR4 hitting the Moon go up again
An asteroid that, until a few months ago, was believed to be a threat to Earth is increasingly looking like it could crash into the Moon in 2032. Asteroid 2024 YR4 was discovered on Dec. 27 by the Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope in Río Hurtado, Chile. Since its discovery, the asteroid has warranted international attention, jumping to the highest asteroid threat on the Torino Impact Hazard Scale. Chances Asteroid 2024 Yr4 Will Hit Moon Increase But Earth Remains In The Clear In February, new ground-based observations dropped those chances of an Earth impact enough that asteroid 2024 YR4 is no longer considered a threat to Earth. The international astronomy community continues to closely watch asteroid 2024 YR4, which is no longer visible through ground-based telescopes until 2028. In May, a team led by Andy Rivkin, with Johns Hopkins Applied Physics Laboratory in Maryland, used the James Webb Space Telescope's (JWST) Near-Infrared Camera to hone in on 2024 YR4. JWST data, along with expert analysis from Nasa's Center for Near-Earth Object Studies, have refined the asteroid's orbit, increasing the chances of a crash with the Moon on Dec. 22, 2032, from 3.8% to 4.3%. In February, the odds of a Moon impact were about 1.7%. However, NASA said if the asteroid does collide with the Moon, it will not alter its orbit. The Moon is covered in crater impacts from other space collisions. Previous observations by JWST helped determine 2024 YR4 is about 200 feet wide, or about the height of a 15-story building, Rivkin wrote in an April blog post for NASA. Asteroid 2024 YR4 has dipped behind the Sun and beyond Webb's view for article source: Odds of asteroid 2024 YR4 hitting the Moon go up again
Yahoo
5 hours ago
- Yahoo
Astronomers left puzzled by high-altitude clouds forming on young planet
Should humans ever venture to a particular planet that circles a sun-like star in the constellation of the fly, they would do well to keep an eye on the weather. The thick slabs of cloud that blot the planet's skies are mostly made from mineral dust, but astronomers suspect there may be iron in them, too, which would rain down on the world below when the clouds break. Astronomers spotted the high-altitude clouds when they trained the James Webb space telescope (JWST) on the young star system, which lies 307 light years away in the deep southern sky. The star, YSES-1, is a newbie by cosmic standards, a mere 1m years old compared with the 4.6bn-year-old sun. The star is circled by two gas giants, both still forming and both larger than Jupiter, the biggest planet in the solar system. Related: Astronomers find signal that gives 'unexpected' insight into early universe Dr Kielan Hoch, an astrophysicist at the Space Telescope Science Institute in Baltimore, Maryland, said the planetary system's youth made it a prime target for astronomers to learn more about the early evolution of planets around faraway stars. 'There's a small handful of multiplanet systems that have been directly imaged,' Hoch said. 'And they are a unique laboratory to test planet formation theories as they formed in the same environment.' 'Both planets are still forming, which is why they are still bright enough for us to detect,' she added. 'The light we are seeing is from their formation as they begin to shrink and condense.' When the team began their observations they were surprised to find both planets in the telescope's field of view, giving them information on two worlds for the price of one. The outer planet, YSES-1c, is the smaller of the two worlds, and about six times the mass of Jupiter. The telescope revealed high-altitude clouds in the planet's atmosphere, but instead of being made from water vapour as on Earth, the clouds consist of magnesium silicate dust grains and perhaps some iron. 'The iron would indeed precipitate out,' Hoch said. The astronomers described the observations as the first direct detection of such clouds on a planet circling a sun-like star. Further data revealed a disc of material made up of trillions of tonnes of dust particles around the larger inner world, YSES-1b, about 14 times the mass of Jupiter. The findings were published in Nature. Hoch said the disc around the inner planet was a 'puzzle for formation theories' since both planets must have formed in the same environment. 'Why did YSES-1b hold on to material around it while YSES-1c did not?' she said. An added mystery is why a 16m-year-old planet still has a disk of material swirling around it. Astronomers' theories of planet formation suggest that any encircling dust should have settled after the first 5m years. 'We wouldn't expect the planets to look so different from one another if they formed in the same protoplanetary disk,' Hoch said. 'JWST is providing an immense amount of data to continue to refine models and improve our understanding.' The $10bn telescope has transformed astronomy since it launched in December 2021 from Europe's Spaceport in French Guiana. The flagship mission has peered back to the first galaxies that lit up the cosmos, spied strange new worlds, and witnessed black holes colliding. It has even spotted tantalising, if controversial, hints of life beyond Earth.
CNET
5 hours ago
- CNET
Anyone Can Now Access the Largest Space Map Ever Created, Here's How
If you've ever wanted a better look at deep space, you now have your chance. A treasure trove of data collected by the James Webb Space Telescope is now available for public consumption. Included with the data is an interactive map that contains nearly 800,000 galaxies and various filters so you can view them in different ways. The data was made available starting on June 5 by the Cosmic Evolution Survey out of Caltech. It consists of survey data that mapped out 0.54 square degrees of the sky. For reference, if you take a look at this month's strawberry moon, the amount of sky that was mapped is equivalent to about three full moons side by side. The total size of all the map data is about 1.5 TB. Read more: Coolest Space Photos of 2025 Will Fill You With Cosmic Wonder Included in the map are galaxies and stars that are 13.5 billion years old, which means it provides the best look into the early universe that science has offered so far. NASA estimates that the universe is 13.8 billion years old, so those galaxies and stars are positively ancient. In all, there are galaxies and stars in the data that cover about 98% of the known universe's history. That makes it bigger than the largest Milky Way galaxy map ever created, which still only covers a small slice of the galaxy's overall layout. However, the Milky Way galaxy map is still larger in terms of data, as that map is over 500 TB in size. Researchers mapped the sky with the JWST's Near Infrared Camera and 0.2 square degrees of the sky with the Mid Infrared Instrument. In total, there's about 1.5 TB worth of data to sift through. Arguably the coolest part of the info dump is the interactive map, which loads in a web browser and allows users to move around and see everything that was included. Clicking on a point of interest shows you data about the star or galaxy you selected. COSMOS2025 Using the interactive map viewer Curious individuals can check out the project's map use the map, you simply have to follow the link and click the "check it out!" button. Once the map loads, you'll see a square-ish image that contains over 700,000 galaxies and other objects. Once you load the map, the best way to view it is using the layers and filters in the top right corner. The first box contains views, including NIRCam RGB and several other views. The second box breaks up the image into tiles. These tiles are how the image was mapped, so you can see which James Webb instrument was used to capture each segment of the map. For education purposes, the third box is the one to use. These options outline the objects of interest. Clicking on them provides you with a catalog ID — which lets you search for those objects again later — along with the raw images taken of each one and additional data points like light wavelength. The tools in the top left are used for search and configuration, like increasing the brightness and changing the hue to make some objects easier to view. With the controls, your best bet is to just look around and find all the cool stuff. At any point,k you can reset all of the settings by refreshing the browser window. How to access the data The data is accessible in a couple of different ways. The COSMOS2025 project published three research papers on the data they collected. The first is a catalog of everything that was observed. The other two focused on the near infrared imaging and mid infrared imaging used to obtain the data. You can obtain the data by filling out this form. Once done, you'll be able to download the data. It's available as a single, large download or you can download individual tiles if you prefer. There are more advanced instructions available from the COSMOS2025 project website if you need them and more data available here if you want to download it. You may notice that the majority of the map data is in the FITS file format. That's an unusual file format that your standard Photoshop or similar app won't be able to handle very well. Fortunately, NASA has a trustworthy list of FITS image viewers that you can choose from. The data will also be used to help answer questions about the early universe, and all this data being freely available to researchers the world over will help with that.
