MIT Technology Review; Fri, 21 Jun 2019 18:43 UTC

The Tibetan Plateau is a vast elevated plain almost five kilometers above sea level, sometimes called the Roof of the World. It is bordered to the south by the world's highest mountain range and to the north by desert lands. It is one of the most isolated places on Earth.

But the extreme altitude makes it a useful place for scientists. In 1990, they built an observatory here to study the showers of subatomic particles that rain down from the upper atmosphere whenever it is hit by a high-energy cosmic ray. This work is better done at high altitude because there is less atmosphere to absorb the particles.

Since then, the so-called Tibet Air Shower Array has recorded vast numbers of high-energy cosmic rays, particles accelerated to huge energies by astrophysical phenomena such as supernovas, active galactic nuclei, and mysterious as-yet-unidentified sources.

But the array also picks up air showers caused by a different source - high-energy photons. These mysterious photons are also created by astrophysical phenomena such as the interaction between high-energy particles and the cosmic microwave background. Consequently, they can provide a unique insight into these processes and the environments in which they occur.

Over the years, the Tibet Air Shower Array has spotted plenty of these photons with energies up to dozens of teraelectronvolts (TeV 1012). That's roughly equivalent to the highest-energy photons that can be created on Earth. But nobody has ever observed more powerful photons.

Until now. Today, researchers from the Tibet Air Shower Gamma Collaboration say they have observed photons with energies above 100 TeV for the first time, including a remarkable photon with an energy of almost 500 TeV. This single photon has about the same energy as a falling Ping-Pong ball and is the highest-energy photon ever recorded.

The collaboration has also worked out where these photons are coming from: the Crab Nebula, the remnants of a supernova that occurred in 1054 AD in the Perseus Arm of the Milky Way, some 6,500 light-years from Earth.

.... read more at https://www.sott.net/article/415559-Earth-hit-by-highest-energy-photons-ever-recorded-from-the-Crab-Nebula

A minor interplanetary shock wave hit Earth on May 26th at approximately 22:00 UT. The CME-like disturbance was unexpected. It caused the density of the solar wind around Earth to abruptly quadruple, while the interplanetary magnetic field doubled in strength. Minor geomagnetic storms are possible on May 27th as our planet passes through the shock wave's wake.
www.spaceweather.com

David Claughton and Olivia Ralph; abc.net.au; 10 Mar 2019

Boorowa farmer Charlie Arnott has experienced the immense toll of drought on his cattle, his business and his wellbeing, but he has found a way through it all. Fifteen years ago, reeling from the effects of the Millennium drought, he attended a workshop on regenerative agriculture that radically changed the way he farmed and, he believes, saved his life. "I was doing a really good job of killing a lot of stuff to try and grow food, which is kind of crazy," Mr Arnott said.

He had been farming conventionally using pesticides, herbicides and fertilisers, but the course taught him how to partner with nature instead of trying to control it. It has turned around his farm's capacity to deal with drought and he currently has plenty of water and grass for his livestock even as the drought in NSW intensifies.

"We haven't fed for 15 years [because] we measure how much grass we have, we know how many animals we have to eat that grass and a very simple calculation gives us the amount of time that that grass is available before it runs out," Mr Arnott said.

From a desert to a paradise

Another farmer in Boorowa, David Marsh, began his journey into regenerative agriculture in the 1980s, after a drought brought him to the edge of ruin. "In 1982 we reduced our numbers far too late, like so many ... and we turned this place into a desert," Mr Marsh said.

"In that time you couldn't give sheep away and I promised I wouldn't do that again."

He began adopting regenerative practices in 1999, increasing the amount of native vegetation and tree coverage on his property from just 3 per cent to 20 per cent.

The rest of this article can be read here: https://www.sott.net/article/409672-From-a-desert-to-a-paradise-Regenerative-agriculture-finds-solid-backing-as-decades-of-success-show-renewal

When a stream of solar wind hits Earth's magnetic field, magnetometers around the Arctic Circle normally go a bit haywire, with their needles swinging chaotically as the buffeting ensues. Rob Stammes of the Polarlightcenter, a magnetic observatory in Norway, sees such disordered behavior all the time. But on Nov. 18th something quite different happened. The solar wind produced a pure sine wave:

"A very stable ~15 second magnetic oscillation appeared in my recordings, and lasted for several hours," he says. "The magnetic field was swinging back and forth by 0.06 degrees, peak to peak."
Imagine blowing across a piece of paper, making it flutter with your breath. The solar wind can have a similar effect Earth's magnetic field. The waves Stammes recorded are essentially flutters propagating down the flanks of our planet's magnetosphere excited by the breath of the sun. Researchers call them "pulsations continuous" -- or "Pc" for short..
"A sensitive magnetometer is required to record these waves," says Stammes. "I use a mechanical magnetometer with bar magnets suspended from a special wire. LEDs and light detectors in an isolated dark box record the motion of the magnets, while vanes in oil damp out non-magnetic interference."
Pc waves are classified into 5 types depending on their period. The Nov. 18th waves fall into category Pc3. Researchers have found that Pc3 waves sometimes flow around Earth's magnetic field and cause a "tearing instability" in our planet's magnetic tail. This, in turn, sets the stage for an explosion as magnetic fields in the tail reconnect.

A quartet of NASA spacecraft recently flew through just such an explosion. Last week, researchers from the University of New Hampshire reported that four Magnetospheric Multiscale (MMS) spacecraft spent several seconds inside a magnetic reconnection event as they were orbiting through Earth's magnetic tail. Sensors on the spacecraft recorded jets of high energy particles emerging from the blast site. One jet was aimed squarely at Earth and probably sparked auroras when it hit the upper atmosphere.
Stammes has recorded many Pc waves in the past, "but this is the first time I have detected category Pc3," he says. "This was a very rare episode indeed."
www.spaceweather.com

Laura Geggel; Live Science; Wed, 07 Nov 2018 09:34 UTC

An eerie, marmalade-colored light show made Earth look like a gigantic orange lollipop, prompting an astronaut aboard the International Space Station to snap a photo of it on Oct. 7. And yesterday, NASA shared the glorious shot with Earthlings down below.

The enveloping orange hue is known as airglow - a mesmerizing luminescence caused by chemical reactions high in Earth's atmosphere, NASA reported. This ghostly glow usually happens when ultraviolet radiation from sunlight energizes molecules of nitrogen, oxygen, sodium and ozone in the atmosphere. These energized molecules then bump into each other and lose energy as they collide, resulting in a faint but spectacular afterglow, NASA said.

Airglow is best seen at night, as it's 1 billion times fainter than sunlight, NASA said. This particular photo was taken at an altitude of more than 250 miles (about 400 kilometers) above Australia.

The radiating blush, also known as chemiluminescence, is comparable to glowing chemical reactions here on Earth, including those seen in children's toys such as glow sticks and glow-in-the-dark silly putty, NASA added.

But airglow is more than an entrancing light attraction. It can also teach scientists about the workings of the upper atmosphere. For instance, it can shed light on how particles near the interface of Earth and space move, including how space weather and Earth weather are connected, NASA said.

Researchers are already using satellites - such as NASA's Ionospheric Connection Explorer (ICON) - to study this dynamic zone.

Although this airglow emanated orange, the phenomenon isn't always the color of the snack food Doritos. In 2016, a photographer in the Azores islands in the Atlantic Ocean took a photo of a rainbow-colored airglow, according to Space.com, a sister site of Live Science.

On Oct. 26th, Venus will pass almost directly between Earth and the sun--an event astronomers call "inferior solar conjunction." As Venus approaches the sun, the planet is turning its night side toward Earth, reducing its luminous glow to a thin sliver. Shahrin Ahmad of Kuala Lumpur, Malaysia, took this picture on Oct. 20th:

"I took this picture in broad daylight," says Ahmad. "Venus was really big in the eyepiece of my telescope--almost a full arcminute in diameter. And the crescent shape easily visible in the 8x50 finder scope."
In the days ahead, the crescent of Venus will become increasingly thin and circular. The horns of the crescent might actually touch when the Venus-sun angle is least (~6 degrees) on Oct. 26th. This is arguably the most beautiful time to observe Venus, but also the most perilous. The glare of the nearby sun magnified by a telescope can damage the eyes of anyone looking through the eyepiece.
Anthony J. Cook of the Griffith Observatory has some advice for observers: "I have observed Venus at conjunction, but only from within the shadow of a building, or by adding a mask to the front end of the telescope to fully shadow the optics from direct sunlight. This is tricky with a refractor or a catadioptric, because the optics start at the front end of the tube. Here at Griffith Observatory, I rotate the telescope dome to make sure the lens of the telescope is shaded from direct sunlight, even through it means that the lens will be partially blocked when aimed at Venus. With our Newtonian telescope, I add a curved cardboard mask at the front end of the tube to shadow the primary mirror."
For the rest of this week Venus can still be observed without elaborate precautions in deep twilight after sunset. Every evening the crescent grows and narrows. Scan the realtime photo gallery for updates.
www.spaceweather.com

The sun is entering a deep Solar Minimum, and Earth's upper atmosphere is responding. Data from NASA's TIMED satellite show that the thermosphere (the uppermost layer of air around our planet) is cooling and shrinking, literally decreasing the radius of the atmosphere. If current trends continue, the thermosphere could set a Space Age record for cold in the months ahead: Full story.
www.spaceweather.co

The northern autumnal equinox is only a week away (23 September). That means one thing: Cracks are opening in Earth's magnetic field. Researchers have long known that during weeks around equinoxes, fissures form in Earth's magnetosphere. Solar wind pours through the gaps to fuel bright displays of Northern Lights. It happened just last night in Rovaniemi, Finland:

"The auroras were totally awesome," says photographer Alexander Kuznetsov. "We weren't expecting a huge storm, yet this was the best display of the new season."

This is called the "Russell-McPherron effect," named after the researchers who first explained it. The cracks are opened by the solar wind itself. South-pointing magnetic fields inside the solar wind oppose Earth's north-pointing magnetic field. North and South partially cancel one another, opening a crack. This cancellation can happen at any time of year, but it happens with greatest effect around the equinoxes. Indeed, a 75-year study shows that September is one of the most geomagnetically active months of the year–a direct result of "equinox cracks."

NASA and European spacecraft have been detecting these cracks for years. Small ones are about the size of California, and many are wider than the entire planet. There's no danger to people on Earth. Our planet's atmosphere intercepts the rush of incoming particles with no harm done and a beautiful afterglow.  Stay tuned for more Arctic lights as autumn approaches.
www.spaceweather.com

WHEN IS THE LIVE EVENT?
The event will start May 1st and continue for 40 days.  We will move through four themes:

• May 1 - 10:   Reconnect with Self
• May 11 - 20:   Reconnect with Each Other
• May 21 - 30:   Reconnect with the Earth
• May 31 – June 9:  Reconnect with the Sacred within All Life

You may join anytime during the 40 Days or after.  Once registered, you will eventually have access to the entire collection of materials.  

GEOMAGNETIC STORM PREDICTED: NOAA forecasters say there is a 75% chance of moderately strong (G2-class) geomagnetic storms on Sept. 13th. That's when a CME hurled into space by a powerful X8-class solar flare on 10 September will likely deliver a glancing blow to Earth's magnetic field. The impact of the CME could be enhanced by a fast-moving solar wind stream, expected to arrive at about the same time. If the G2-storm materializes, auroras in the USA could appear as low as New York to Wisconsin to Washington state.

SOLAR RADIATION STORM AND GROUND LEVEL EVENT: On Sept. 10th, departing sunspot AR2673 erupted, producing a powerful X8-class solar flare. The explosion propelled a CME into space and accelerated a swarm of energetic protons toward Earth. Both are visible in this coronagraph movie from the Solar and Heliospheric Observatory (SOHO):

The many specks in this movie are not stars--they are solar protons striking SOHO's digital camera. Almost two days later these protons are still streaming past our planet, causing a moderately strong (S2-class) solar radiation storm. The latest data from SOHO show an ongoing blizzard of digital "snow" in coronagraph images:

What made this flare so 'radioactive'? It has to do with the location of AR2673 at the time of the explosion. The sun's western limb is magnetically well-connected to Earth. Look at this diagram. Magnetic fields spiraling back from the blast site led directly to our planet, funneling these energetic protons Earthward.

Normally, solar radiation storms are held at bay by our planet's magnetic field and upper atmosphere. On Sept.10th, however, there was a "ground level event" (GLE). Neutron monitors in the Arctic, Antarctic, and several other high latitude locations detected a surge of particles reaching all the way down to Earth's surface:

"In historical terms, this was a relatively small ground level event-- only about one thousandth as strong as the event of 23 Feb 1956, which is the largest measured," says Clive Dyer, a Visiting Professor at the University of Surrey Space Centre.

However, that does not mean the Sept.10th GLE was negligible. Dyer says that "passengers flying on high-latitude routes at 40,000 feet could have absorbed an extra 10 microSieverts of radiation. During the first hour of the GLE, the dose rate inside the aircraft during such a flight would have approximately doubled."

He also notes that the GLE could have caused minor upsets of onboard electronics and avionics, although nothing on the scale of the epic 1956 GLE, "which would be very challenging to modern systems."

"Since measurements began around 1942 there have now been 73 events detected by ground level radiation monitors," Dyer adds. "The Sept.10, 2017, event is far from the strongest, but it is of special interest because it demonstrates the need for continual vigilance even during Solar Minimum."      www.spaceweather.com