Back in 2008, the solar cycle plunged into the deepest minimum in nearly a century. Sunspots all but vanished, solar flares subsided, and the sun was eerily quiet.
"Ever since, we've been waiting for solar activity to pick up," says Richard Fisher, head of the Heliophysics Division at NASA Headquarters in Washington DC. "It's been three long years."
Quiet spells on the sun are nothing new. They come along every 11 years or so—it's a natural part of the solar cycle. This particular solar minimum, however, was lasting longer than usual, prompting some researchers to wonder if it would ever end.
News flash: The pot is starting to boil. "Finally," says Fisher, "we are beginning to see some action."
As 2011 unfolds, sunspots have returned and they are crackling with activity. On February 15th and again on March 9th, Earth orbiting satellites detected a pair of "X-class" solar flares--the most powerful kind of x-ray flare. The last such eruption occurred back in December 2006.
Another eruption on March 7th hurled a billion-ton cloud of plasma away from the sun at five million mph (2200 km/s). The rapidly expanding cloud wasn't aimed directly at Earth, but it did deliver a glancing blow to our planet's magnetic field. The off-center impact on March 10th was enough to send Northern Lights spilling over the Canadian border into US states such as Wisconsin, Minnesota, and Michigan.
"That was the fastest coronal mass ejection in almost six years," says Angelos Vourlidas of the Naval Research Lab in Washington DC. "It reminds me of a similar series of events back in Nov. 1997 that kicked off Solar Cycle 23, the solar cycle before this one."
"To me," says Vourlidas, "this marks the beginning of Solar Cycle 24."
The slow build-up to this moment is more than just "the watched pot failing to boil," says Ron Turner, a space weather analyst at Analytic Services, Inc. "It really has been historically slow."
There have been 24 numbered solar cycles since researchers started keeping track of them in the mid-18th century. In an article just accepted for publication by the Space Weather Journal, Turner shows that, in all that time, only four cycles have started more slowly than this one. "Three of them were in the Dalton Minimum, a period of depressed solar activity in the early 19th century. The fourth was Cycle #1 itself, around 1755, also a relatively low solar cycle," he says.
In his study, Turner used sunspots as the key metric of solar activity. Folding in the recent spate of sunspots does not substantially alter his conclusion: "Solar Cycle 24 is a slow starter," he says.
Better late than never.Dr. Tony Phillips
Susan Hendrix | EurekAlert!
From rocks in Colorado, evidence of a 'chaotic solar system'
23.02.2017 | University of Wisconsin-Madison
Prediction: More gas-giants will be found orbiting Sun-like stars
22.02.2017 | Carnegie Institution for Science
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
24.02.2017 | Life Sciences
24.02.2017 | Life Sciences
24.02.2017 | Trade Fair News