Regular readers may recall how we have occasionally reported on magnetic sine waves rippling through Earth's magnetic field, causing the magnetosphere to ring like a bell. On Jan. 16th, Jeff Dai looked up and actually saw one of those waves over the Kerid Crater in Iceland:

"I captured this rare image of 'aurora curls," says Dai. "They rippled across the zenith for several minutes."

Dai, who is vacationing in Iceland from China, asked Xing-Yu Li of Peking University's Institute of Space Physics and Applied Technology for help in understanding the aurora curls. "Imagine that Earth's magnetic field is like a guitar string," says Li. "In Jeff Dai's picture we are seeing vibrations in that string." Their wavelength, Li estimates, is several kilometers.

2023 started with snowfall in eastern and southeastern parts of the Netherlands and ended with record high water levels due to record-breaking rainfall. The wettest year since measurements began also included other destructive weather events such as storms and tornadoes. Below are some highlights from extreme weather events in the Netherlands in 2023.

'We've never had this kind of look at an exploded star before.'
The bizarre, grinch-like wisp of green light dubbed the Green Monster, first seen last year snaking through the glowing remnants of an exploded star, belongs to a blast wave bordering the debris field, a new study reveals.

Last April, NASA's James Webb Space Telescope (JWST or Webb) photographed the unusual "wall of emission" in front of Cassiopeia A (or Cas A), an expanding shell of hot gas roughly 11,000 light-years from Earth whose light first reached us 340 years ago. For the past year, astronomers have been trying to explain its origin and presence in the well-studied supernova remnant.

The new image, unveiled on Monday (Jan. 8) at the American Astronomical Society conference being held in New Orleans and online, combines the observing powers of Webb, as well as NASA's Hubble, Spitzer and Chandra space telescopes, to feature Cas A in unprecedented detail. The ball of light, which stretches for 10 light-years, appears infused with red clouds, revealing dust likely warmed as it resides within gas that was heated up to millions of degrees. White, green and orange light streaks sprinkled throughout offer a cosmically messy, breathtaking new view of the stellar debris.

Rare 'rainbow' clouds have been spotted across Ireland this morning.

The clouds have an iridescent or rainbow appearance and their presence is rare in Ireland.

The technical name for the eye-catching clouds are nacreous or polar stratospheric clouds.

In and around the Arctic Circle, stunning multicolor clouds have been shining in the sky for days on end. It is very unusual to see so many of these vibrant clouds over such a long period.
"Spectacular" rainbow-colored clouds have been shimmering in the skies over and around the Arctic for more than three days thanks to an unusual cold snap in the upper atmosphere. And even more of these technicolor treats could appear during the next few months, experts say.

The colorful clouds, known as polar stratospheric clouds (PSCs), were spotted floating high in the sky above parts of Norway, Sweden, Finland and Alaska, and even as far south as Scotland. They began to emerge on Dec. 18 and continued to appear clearly until Dec. 20, according to Spaceweather.com. Some smaller, less distinct clouds were also spotted on Dec. 21, but in general they seem to be disappearing.

Photographer Ramunė Šapailaitė captured staggering photos of the rare phenomenon above Gran in southern Norway. Her photos revealed the rainbow hues of PSCs and their iridescent shimmer that has inspired the nickname nacreous clouds, due to their similarity with nacre — an iridescent material, also known as mother-of-pearl, that is found in the shells of some mollusks.

"The colors are spectacular," Šapailaitė told Spaceweather.com. "The clouds were visible in the sky all day, but the colors really exploded just before sunset."

The PSCs were caused by a prolonged period of unusually cold temperatures in the sky, according to Spaceweather.com.

Mysterious features hide in near-infrared light

Objects in space reveal different aspects of their composition and behavior at different wavelengths of light. Supernova remnant Cassiopeia A (Cas A) is one of the most well-studied objects in the Milky Way across the wavelength spectrum. However, there are still secrets hidden within the star's tattered remains.

The latest are being unlocked by one of the newest tools in the researchers' toolbox, NASA's James Webb Space Telescope — and Webb's recent look in the near-infrared has blown researchers away.

Like a shiny, round ornament ready to be placed in the perfect spot on a holiday tree, supernova remnant Cassiopeia A (Cas A) gleams in a new image from NASA's James Webb Space Telescope.

As part of the 2023 Holidays at the White House, First Lady of the United States Dr. Jill Biden debuted the first-ever White House Advent Calendar. To showcase the "Magic, Wonder, and Joy" of the holiday season, Dr. Biden and NASA are celebrating with this new image from Webb.

While all is bright, this scene is no proverbial silent night. Webb's NIRCam (Near-Infrared Camera) view of Cas A displays this stellar explosion at a resolution previously unreachable at these wavelengths. This high-resolution look unveils intricate details of the expanding shell of material slamming into the gas shed by the star before it exploded.

Cas A is one of the most well-studied supernova remnants in all of the cosmos. Over the years, ground-based and space-based observatories, including NASA's Chandra X-Ray Observatory, Hubble Space Telescope, and retired Spitzer Space Telescope have assembled a multiwavelength picture of the object's remnant.

However, astronomers have now entered a new era in the study of Cas A. In April 2023, Webb's MIRI (Mid-Infrared Instrument) started this chapter, revealing new and unexpected features within the inner shell of the supernova remnant. Many of those features are invisible in the new NIRCam image, and astronomers are investigating why.

A distant comet trapped in orbit between Saturn and Uranus is accompanied by a transforming disk of icy dust, new observations reveal.

A bizarre object that sometimes gets as close to the sun as Saturn, and other times retreats as far out as Uranus, has been discovered to have a transforming disk of dust around it that changes shape and can even mimic rings.

Minor planet 2060 Chiron is what's known as a Centaur, which are captured cometary objects that travel around the sun on looping orbits between Jupiter and Neptune. Chiron is just 218 kilometers (135 miles) across and occasionally has outbursts like a comet. To date, however, no spacecraft has ever visited a Centaur.

In 2011, Chiron passed in front of a faint star from our point of view here on Earth. Such events are referred to as "stellar occultations," and based on how an object such as Chiron blocks a star's light, the occulting object's shape and size can be determined through deduction. During the 2011 occultation, it was noticed that the star's light dimmed slightly — twice before Chiron itself occulted the star, and two further times after Chiron had moved past the star. This observation was interpreted as Chiron having a double-ring system of dust.

Then, Chiron occulted another star on Nov. 28, 2018, in an event taken advantage of by Amanda Sickafoose, who is a senior scientist at the Planetary Science Institute in Tucson, Arizona. Because Chiron's shadow cast by the star is so small, it crossed only a narrow region of the Earth, clipping southern Africa. Sickafoose therefore led a team who used the 1.9-meter (6.2 feet) telescope at the South African Astronomical Observatory in Sutherland, South Africa, to observe the occultation.

Their results, published exactly five years later, tell a slightly different story to 2011.

In an extraordinary celestial display, the skies over Mongolia turned deep, blood-red as the country experienced one of the rarest auroral events on Friday and early Saturday.

The intense colouration is attributed to the initial impact of a significant solar storm that collided with Earth, creating a spectacle that left onlookers in awe.

The phenomenon, known as an aurora, typically occurs closer to the poles and is often green in colour. However, the auroras seen in Mongolia were of a striking crimson hue, a rarity caused by the interaction of solar particles with oxygen at high altitudes — over 241 kilometres above the Earth's surface, where the atmosphere is much thinner.

The ozone hole over Antarctica keeps intriguing by its unusual pattern this 2023 season. The Southern Hemisphere ozone hole size had a series of rebounds in late November, as shown by the Copernicus Atmosphere Monitoring Service (CAMS) data, at a period when it usually declines until its closure. This behaviour raises questions about what's behind yet another peculiar ozone hole season.

The Southern Hemisphere ozone hole is unusually large, at a time when it normally reduces until its total closure, generally in December. Instead, since the end of October the ozone hole area has virtually remained unchanged, with a series of rebounds, remaining at a size of some 15 km², to become the third largest after 30 November.

A research team has revealed that if an intergalactic star comes within 100 astronomical units of the Sun, it could disturb Earth's orbit and habitability. The team analyzed 12,000 scenarios, revealing a 95% likelihood that all planets would survive, albeit with changed orbits. This shows our Solar System's amazing resilience and unpredictability.

Stars are typically held in place within their galaxies by the force of gravity, allowing them to peacefully coexist with their celestial surroundings. However, on occasion, this delicate bond gets shattered. For instance, a star wandering too near to a huge black hole, can be violently flung into space as a rogue star. What would happen if such a star approached our very own Earth? While the chances are remote, they are not entirely nonexistent.

Over billions of years, the Solar System has reached a stable state. Planets orbit steadily, and the Sun remains at the center. But the arrival of another star could upset this delicate balance. Earth, a small planet with only a minuscule fraction of the Sun's mass, relies heavily on solar gravitational pull. The introduction of a new star's gravity could drastically alter the Earth's fate.

A recent study investigates the effects of a rogue star approaching within 100 astronomical units (1 AU = 149.6 million kilometers) of the Sun. The research team led by Sean Raymond and others from the Laboratoire d'Astrophysique de Bordeaux, CNRS (National Center for Scientific Research), and the Universite de Bordeaux will soon be published in the Monthly Notices of the Royal Astronomical Society.