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An artistic presentation created on behalf of NASA illustrates how solar activity affects the conditions both in the space near us and on the Earth itself. Greek professor of space physics Vassilis Angelopoulos, head of NASA's mission for studies of solar storms in the Earth's magnetic field, observes the mechanism by which the solar wind distorts the Earth's magnetic field and how this results in the arrival of big energy loads on Earth.

Prof. Vassilis Angelopoulos, www.parousiazw.gr

Europe sinks into darkness, mobile phones stop working, aircraft GPSs lose signal, passengers on a plane flying over the North Pole are subjected to huge amounts of radiation, while the Greek sky is illuminated by multi-coloured reflections. Although extreme meteorological phenomena from space have not "hit" the Earth in recent years, such a catastrophic scenario is not science fiction.

The greatest solar storm was recorded in 1859 by astronomer Richard Carrington and was visible in Mexico. "There is a 12% probability of an event such as the Carrington phenomenon happening over the next decade," says astrophysicist Pete Riley in a publication in the Space Weather journal of 2012. Such a phenomenon will cause enormous damage to satellites and power lines, as told to Kathimerini newspaper by Vassilis Angelopoulos, professor of Space physics at the University of California at Los Angeles and director of two NASA missions studying the phenomenon of space weather, and namely the effect of solar activity on the Earth's magnetic field.

Prevailing temperatures in the Sun's atmosphere usually reach 20,000 degrees Celsius. The magnetic activity of the Sun, however, often warms some parts of its atmosphere too much, in this way creating solar flares which are seen as bright spots from Earth. This hot dense gas mass, which reaches one million degrees Celsius, cannot be retained by the attractive force of the gravitational field of the Sun and goes towards planets. If, for example, the surface of the sun was boiling water, the dense gases, or as they are called, the solar wind, would be the steam coming out of the saucepan. The solar wind "hits" neighbouring planets, affects their magnetic field and causes the phenomenon of space weather or solar storms.

Measurements of the Sun

A few days ago, an international team of researchers, led by Jaroslaw Dudik of Cambridge University in the UK, said that the mechanism of solar flares has been observed for the first time, confirming the theory which first appeared about 20 years ago. Based on this theory and in conjunction with subsequent calculations, Dudik’s French colleagues started designing three-dimensional models in 2006, which represent spiral lines of the magnetic field of the Sun which are responsible for the blasts appearing on its surface.

As the researchers wrote in the April issue of The Astrophysical Journal, a team of four telescopes of the Solar Dynamics Observatory mission of NASA, generating stereoscopic images with high resolution every 12 seconds, has recorded a video of a magnetic activity of the Sun, resulting in an eruption which was 35 times larger than the Earth, in this way confirming the patterns of the French scientists. "Knowing now what the process by which the Sun radiates energy is will help us predict the amount of this energy," said lead researcher Dr. Dudik for Kathimerini. "The better the models, the greater the accuracy of the prediction of the direction of the solar wind, as well as the speed with which it left the Sun and whether it can hit the Earth," added Dr. Angelopoulos.

Solar storm, www.pontos-news.gr

Measurements of the Earth

"I was very impressed by the fact that the observations on the Sun of scientists at Cambridge are very much the same as what we believe is happening on Earth due to the solar wind," said Dr. Angelopoulos, who studies the phenomenon of space-time in the Earth's magnetic field magnetosphere. Head of two NASA missions - "Themis" and "Artemis" (a fleet of satellites studying the way solar storms are created in the magnetosphere of the Earth) - Dr. Angelopoulos has recently made a breakthrough. "Although we saw their existence, we did not know what caused this huge release of energy on Earth," said Dr. Angelopoulos, who believes that the answer lies in the phenomenon of magnetic joining, during which the two oppositely charged magnetic poles collide, in this way releasing large amounts of energy.

While passing through the Earth, the solar wind pulls its magnetic field, causing it to "stretch" millions of kilometres, gaining a shape resembling a wind-cone. At this point, when the magnetic field lines of the magnetic field finally manage to meet, energy is released which hits the Earth's atmosphere, creating a glow, explained Dr. Angelopoulos in a publication of his scientific team in the Science journal of September last year.

Aurora, aurora-gallery-news.blogspot.com

Research