Sydney: In what is a surprising discovery, scientists have found tsunami-style towering waves that race across the face of the Sun.
According to a report in ABC News, the Solar and Heliospheric Observatory provided a tantalizing glimpse of a solar wave about 12 years ago, but it took the three-dimensional view from NASA’s STEREO solar probes to nail it.
“It came as a surprise to us when we started seeing these waves expanding,” said Joseph Gurman, a solar physicist with NASA’s Goddard Space Flight Center .
The waves, which are comprised of plasma, appear at the base of the corona, a couple of thousand kilometres above the surface of the sun.
They rise quickly from a central point and spread out in a circular pattern millions of kilometres in circumference.
Scientists, using the Solar Terrestrial Relations Observatory (STEREO), confirmed the existence of solar waves in February 2009 when a sunspot erupted, sending a cloud of gas into space and a 100,000-kilometre-high tsunami sprinting across the surface of the sun at about 900,000 kilometres per hour.
The twin STEREO satellites recorded the wave from two positions, giving researchers a three-dimensional view of what had happened.
“The satellites allowed us to determine without doubt the true nature of the wave,” said lead researcher Assistant Professor Spiros Patsourakos, with George Mason University.
The waves are associated with flares and solar storms known as coronal mass ejections, which spew billions of tons of plasma and embedded magnetic fields from the sun’s corona into interplanetary space.
Plasma that encounters earth’s magnetosphere can trigger powerful geomagnetic storms that can interfere with Global Positioning System radio signals, satellites and other technologies.
Studying how the waves grow and travel should give scientists fresh insights into the sun’s magnetic environment, according to Gurman.
“Monitoring for waves also should allow solar physicists to pinpoint the source of coronal mass ejections that may be heading toward earth,” said Simon Plunkett, with the US Naval Research Laboratory in Washington DC.
ANI
First Published: Monday, December 07, 2009, 14:53