Eideard

After a weekend filled with great auroral activity in Northern Canada and Scandinavia thanks to a strong gust of solar wind coming off the Sun January 19th, the Earth is about to get hit again – by the biggest blast of solar radiation in 7 years. Talk about a one-two punch on the cosmic scale!

Late last night…a giant, long lasting, solar flare erupted off the face of the Sun, sending a giant Coronal Mass Ejection – cloud of plasma and charged particles – squarely towards the Earth. Detected by NASA’s sun-monitoring satellites SOHO and STEREO, the solar blast was determined to be an M9 on the Richter scale of solar flares – just shy of an X- class flare which is ranked as the most powerful. Space weather forecasters at NOAA – who keep watch for any hazardous, incoming solar storms – are expecting the brunt of the CME to slam into Earth’s magnetic field Jan.24 around 9 am EST (2 pm UT) +/- 7 hours…

Already the front of the storm is now being felt as space radiation (energized protons) speeds by Earth, states the Spaceweather.com website. The high influx of charged particles hitting the magnetic field poses a hazard to everything from GPS signals, polar radio communications, power grids and circuit boards on orbiting satellites.

What does this mean for chances of seeing Northern Lights? If the geomagnetic storm becomes moderate to strong then auroras may creep down to southern latitudes like Texas and Georgia – but that’s pretty rare. Exactly how intense and widespread the sky show will be depends on how our planet’s magnetic field is oriented at the time when the storm arrives.

Best time to go outside will be between local midnight and pre-dawn hours. Face the northern sky and look for green or red glows to start near the horizon. Catching auroras with your camera is not hard. All you need to have is a tripod mounted DSLR camera with a wide angle lens, capable of taking exposures of up to 20 seconds with a timer.

You don’t even need it to be a DSLR – just a decent camera that can handle a 20 second exposure. My “big” camera has a wireless remote that will let me open and then close the shutter for any time period I feel like counting off.

But, I don’t expect to see any aurora at this latitude. Yes – I will go outside and look, though.

Scientists understand that Earth’s magnetic field has flipped its polarity many times over the millennia. In other words, if you were alive about 800,000 years ago, and facing what we call north with a magnetic compass in your hand, the needle would point to ‘south.’ This is because a magnetic compass is calibrated based on Earth’s poles. The N-S markings of a compass would be 180 degrees wrong if the polarity of today’s magnetic field were reversed. Many doomsday theorists have tried to take this natural geological occurrence and suggest it could lead to Earth’s destruction. But would there be any dramatic effects? The answer, from the geologic and fossil records we have from hundreds of past magnetic polarity reversals, seems to be ‘no.’

Reversals are the rule, not the exception. Earth has settled in the last 20 million years into a pattern of a pole reversal about every 200,000 to 300,000 years, although it has been more than twice that long since the last reversal. A reversal happens over hundreds or thousands of years, and it is not exactly a clean back flip. Magnetic fields morph and push and pull at one another, with multiple poles emerging at odd latitudes throughout the process. Scientists estimate reversals have happened at least hundreds of times over the past three billion years…

Earth’s polarity is not a constant. Unlike a classic bar magnet, or the decorative magnets on your refrigerator, the matter governing Earth’s magnetic field moves around. Geophysicists are pretty sure that the reason Earth has a magnetic field is because its solid iron core is surrounded by a fluid ocean of hot, liquid metal…The flow of liquid iron in Earth’s core creates electric currents, which in turn create the magnetic field. So while parts of Earth’s outer core are too deep for scientists to measure directly, we can infer movement in the core by observing changes in the magnetic field. The magnetic north pole has been creeping northward – by more than 600 miles (1,100 km) – since the early 19th century, when explorers first located it precisely. It is moving faster now, actually, as scientists estimate the pole is migrating northward about 40 miles per year, as opposed to about 10 miles per year in the early 20th century.

Another doomsday hypothesis about a geomagnetic flip plays up fears about incoming solar activity. This suggestion mistakenly assumes that a pole reversal would momentarily leave Earth without the magnetic field that protects us from solar flares and coronal mass ejections from the sun. But, while Earth’s magnetic field can indeed weaken and strengthen over time, there is no indication that it has ever disappeared completely. A weaker field would certainly lead to a small increase in solar radiation on Earth – as well as a beautiful display of aurora at lower latitudes — but nothing deadly. Moreover, even with a weakened magnetic field, Earth’s thick atmosphere also offers protection against the sun’s incoming particles.

I couldn’t resist posting this. I know a Christian science teacher who’s stuck into the idea of incoming solar activity roasting us on the playing field of life. I’m not certain if he plans to purchase some kind of anti-radiation suit or just move underground for a couple hundred years.

Scientists say they can now explain the existence of what are perhaps Earth’s most extraordinary mountains.

The Gamburtsevs are the size of the European Alps and yet they are totally buried beneath the Antarctic ice. Their discovery in the 1950s was a major surprise. Most people had assumed the rock bed deep within the continent would be flat and featureless.

Survey data now suggests the range first formed over a billion years ago, researchers tell the journal Nature.

The Gamburtsevs are important because they are thought to be the location where the ice sheet we know today initiated its march across Antarctica. Unravelling the mountains’ history will therefore inform climate studies, helping scientists to understand not just past changes on Earth but possible future scenarios as well…

This multinational effort in 2008/2009 flew aircraft back and forth across the east of the White Continent, mapping the shape of the hidden mountain system using ice-penetrating radar. Other instruments recorded the local gravitational and magnetic fields, while seismometers were employed to probe the deep Earth.

The AGAP team believes all this data can now be meshed into a credible narrative for the Gamburtsevs’ creation and persistence through geological time…

“This research really solves the mystery of how you can have young-looking mountains in the middle of an old continent,” said US principal investigator Dr Robin Bell from the Lamont-Doherty Earth Observatory of Columbia University.

“In this case, the original Gamburtsevs probably completely eroded away only to come back, phoenix-like. They’ve had two lives,” she told BBC News…

The search also goes on for a suitable place in the range to drill for ancient ice.

By examining bubbles of air trapped in compacted snow, it is possible for researchers to glean details about past environmental conditions, including temperature and the concentration of gases in the atmosphere such as carbon dioxide.

Somewhere in the Gamburtsev region there ought to be a location where ices can be retrieved that are more than a million years old. This would be at least 200,000 years older than the most ancient Antarctic ice cores currently in the possession of scientists.

RTFA. Please. Another interesting addition to paleo-climatology and geology.

Thanks, Ursarodinia

The solar system is passing through an interstellar cloud that physics says should not exist. In the Dec. 24th issue of Nature, a team of scientists reveal how NASA’s Voyager spacecraft have solved the mystery.

“Using data from Voyager, we have discovered a strong magnetic field just outside the solar system,” explains lead author Merav Opher… “This magnetic field holds the interstellar cloud together and solves the long-standing puzzle of how it can exist at all.”

The discovery has implications for the future when the solar system will eventually bump into other, similar clouds in our arm of the Milky Way galaxy.

Astronomers call the cloud we’re running into now the Local Interstellar Cloud or “Local Fluff” for short. It’s about 30 light years wide and contains a wispy mixture of hydrogen and helium atoms at a temperature of 6000 C…”The observed temperature and density of the local cloud do not provide enough pressure to resist the ‘crushing action’ of the hot gas around it,” says Opher.

So how does the Fluff survive? The Voyagers have found an answer.

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