Earlier this year, researchers announced that long, narrow streaks of purple light occasionally observed in the nighttime sky are not a new type of aurora, as first suspected, but a novel upper atmospheric phenomenon. Dubbed Strong Thermal Emission Velocity Enhancement (STEVE) because of their association with fast-moving ions and hot electrons in Earth's ionosphere, these celestial lights are often visible at lower latitudes than most auroras and appear to be caused by a different, and still undetermined, mechanism.

To better characterize STEVE, Gallardo-Lacourt et al. conducted the first statistical analysis of this optical phenomenon. Using NASA's Time History of Events and Macroscale Interactions during Substorms (THEMIS) ground-based All-Sky Imager array and the Canadian Space Agency's Redline Geospace Observatory (REGO) databases, the team identified and analyzed optical data from 28 STEVE events that occurred between December 2007 and December 2017.

Evidence of an unusually strong solar storm that hit Earth in 660 BCE has been detected in Greenland ice cores-a finding which shows we still have lots to learn about these disruptive events.

An extreme form of solar storm, known as a solar proton event (SPE), struck our planet 2,679 years ago, according to new research published today in Proceedings of the National Academy of Sciences. If an event of such magnitude were to happen today, it would likely wreak havoc on our technological infrastructure, including communications and navigation. Lund University geologist Raimund Muscheler and his colleagues presented evidence in the form of elevated levels of beryllium-10 and chlorine-36 isotopes embedded within ancient Greenland ice cores.

It's now the third massive SPE known to scientists, the others occurring 1,245 and 1,025 years ago. This latest discovery means solar storms of this variety are likely happening more frequently than we thought-perhaps once every 1,000 years-but more data is required to create more reliable estimates.

SPEs happen in the wake of a massive solar flare or coronal mass ejection on the Sun. These stellar events send streams of particles, including high-energy protons, toward Earth, where they interact with the Earth's atmosphere, triggering reactions that increase the rate of radionuclide production, including carbon-14, beryllium-10, and chlorine-36 (radionuclides are unstable atoms with excess nuclear energy). Traditionally, SPEs have been detected as spikes of carbon-14 in tree rings, but they can also be spotted as spikes of beryllium-10 and chlorine-36 in ancient ice cores. The authors of the new study said scientists tend to overemphasize carbon-14 at the expense of searching for other markers, and that "efforts to find [SPEs] based solely on [carbon-14] data likely lead to an underestimated number of such potentially devastating events for our society."

A recent article in the British newspaper The Express titled, "Northern Lights in the UK: Can you watch Aurora Borealis from UK? Where can you see it?" raises interesting questions and comparisons with historical events. It also appears to reinforce the climate forecasts for the next few decades.

Source: Daily Express

Sir Edmund Halley (1656 - 1742) was one of the great astronomers in history. He proved his science in the best way possible by making an accurate prediction. He predicted the return of a comet that they then named after him. I became familiar with his work while working on the climate record of the Hudson's Bay Company (HBC) at Churchill, Manitoba.

The record was given a great scientific boost when in 1768/9 two astronomers, William Wales and Joseph Dymond arrived in Churchill to measure the Transit of Venus. Halley first identified this event and devised a procedure to gather data to determine the distance of the Earth from the Sun. This distance was critical to accurately testing Newton's theory of gravity. A Transit occurred in 1761, but lack of knowledge and a useable technique resulted in failure. The 1769 Transit was critical because another Transit would not occur for 105 years.

An international team of astronomers has untangled new insight into the birth of coronal mass ejections, the most massive and destructive explosions from the sun.

In a paper published in the journal Science Advances, a team led by Tingyu Gou from the University of Science and Technology of China was able to clearly observe the onset and evolution of a major solar eruption for the first time.

From a distance the sun seems benevolent and life-giving, but on closer inspection it is seething with powerful fury. Its outer layer - the corona - is a hot and wildly energetic place that constantly sends out streams of charged particles in great gusts of solar wind.

It also emits localised flashes known as flares, as well as enormous explosions of billions of tons of magnetised plasma called coronal mass ejections (CMEs).

These eruptions could potentially have a big effect on Earth. CMEs can damage satellite electronics, kill astronauts on space walks, and cause magnetic storms that can disrupt electricity grids.

Talk about a heavenly view. Shining among the clouds hovering over a seaside town in Italy, a man captured what appeared to be Jesus Christ illuminated in the sky, arms spread out wide during sunset.

The now-viral image, taken on March 1, shows golden sun rays beaming down over the Tyrrhenian Sea near the western coast of Italy, seeming to take the shape of the religious figure through a break in the clouds.

"As soon as I saw that luminous image, I felt a great need to take it and share it," Alfredo Lo Brutto told Barbara Di Palma, a reporter for "La Vita In Diretta," a news and entertainment show on Italian TV. "I immediately recognized her as the image of Christ the Redeemer, with open arms, as if he wanted to bless the whole city of Agropoli."

Lo Brutto captured the photo at the Piazza Sanseverino in his hometown of Agropoli, a small town near Italy's scenic Amalfi Coast about an hour and a half drive south of Pompeii.

Astronomers have discovered a distant galaxy that's giddily blowing bubbles like a toddler with a glass of chocolate milk. Unlike milk bubbles, however, these two huge galactic balloons are filled with gas, stretch a few thousand light-years across and appear to be crackling with charged particles 100 times more energetic than any found on Earth.

Using data from the Hubble Space Telescope and NASA's Chandra X-Ray Observatory, researchers detected the bubbles jiggling near the center of a galaxy named NGC 3079, located about 67 million light-years away from Earth. Bubbles like these are known as "superbubbles" because, well, they're supersized. According to the team's study in the Feb. 28 issue of The Astrophysical Journal, one of the newly discovered bubbles measures 4,900 light-years across, and the other measures 3,600 light-years across. (For comparison, the diameter of Neptune's orbit around the sun is about 5.6 billion miles, or 9 billion kilometers - one-thousandth of one light-year.)

Superbubbles form when powerful shock waves shove the gases released by stars far into space, leaving a bubble-shaped cavity behind. Scientists still don't fully understand how these massive gas cavities form.

Spectacular photos of iridescent clouds in the Bucegi Mountains, Romania have gone viral on the internet. Captured at sunset by photographer Răzvan Neagoe the phenomenon lasted for 20 minutes on Sunday 24th February 2019 reports stirileprotv.ro.

The complex astronomical measurements that underpinned many aspects of the Inca civilisation may have an ancient forerunner of 10 centuries earlier and 2000 kilometres distant, a prominent archeoastronomer suggests.

Steven Gullberg, of the University of Oklahoma, US, and chair of the International Astronomical Union Working Group for Archaeoastronomy and Astronomy in Culture, is the latest scientist to comment on the origin and purpose of some mysterious stones and engravings, known as petroglyphs, at a site known as La Silla, in Chile.

The complex designs etched in rock, together with a set of standing stones, were first studied in depth by researchers - including this writer - in 2012.

It was suggested that the artefacts were set up to mark the positions of two very brilliant stars, Canopus and Hadar, and were the work of the El Molle, a pre-Columbian culture that occupied the region for five centuries from about 300 CE.

Curiously, La Silla is today the site of a facility built and operated by the European Southern Observatory (ESO), an important part of the global infrastructure for astronomers.

If the tentative conclusions about the petroglyphs and standing stones are correct, the site has been a critical place for star-gazers for at least 1700 years.

Stars jostling around the galaxy aren't quite like a cosmic game of pool. But they do have occasional near misses as they speed past each other. Back when spears and stone points were the height of human technology, astronomers say, our solar system had a close encounter of the interstellar kind.

The brief visitor was Scholz's star, and it might have grazed the outer edge of the solar system's distant Oort Cloud about 70,000 years ago - carrying its companion, a likely brown dwarf, along for the ride.

It's unclear whether the near miss was close enough to give objects in the Oort Cloud, our solar system's halo of dormant comets, a gravitational nudge to fall toward the Sun. But the interstellar trespasser highlights a sometimes-forgotten reality: On long time scales, stars seem to fly around like sparks from a campfire, occasionally coming close enough to disturb each other's cometary clouds.

Such close passes could have profound implications for exoplanets - planets orbiting other stars - and how they got where they are. At least some of the time, an interloper could become a thief, stripping a star of one or more planets - or vice versa.

Our solar system, too, might have been shaped and sculpted by stellar flybys.

A 2018 study showed that the orbital motions of some of our solar system's small bodies appear still to bear the imprint of Scholz's gravitational wake. And some planet-like objects in the Kuiper belt, the collection of rocky and icy bodies past the orbit of Neptune, could have been stolen from another star far earlier - in fact, soon after our Sun was born. Scholz's flyby could just be the latest in a series.

The discovery of our star-crossed close encounter was almost as random as the event itself.