Nov 19, 2010 08:01 GMT  ·  By

Astronomers have recently observed an interesting phenomenon taking place on the surface of the Sun. The star generated what can best be described as a huge snake-like structure made of plasma, which grew to impressive size.

The plasma tendril eventually extended over hundreds of thousands of miles of the solar surface, researchers say. A special NASA telescope was used to keep track of the solar event as it unfolded.

The space agency's Solar Dynamics Observatory (SDO) is especially well-suited to conduct investigations of this nature, and it is keeping track of the Sun's activities in many wavelengths, including extreme ultraviolet (EUV).

According to reports from Spaceweather.com, the structure was found on Tuesday, November 16, as the SDO was carrying out its routine observations of the star. Data downloaded from the observatory showed that the filamet is more than 600,000 kilometers (some 372,800 miles) long.

Solar experts say that there are now two main avenues of development for this structure. The tendril can either subside, and then reenter the solar surface, or it can erupt in the form of a powerful solar storm.

“The filament has several options: relaxing gently back into the Sun, snapping explosively, or crashing down upon the stellar surface,” explains Tony Phillips, as quoted by Space.

“Although an eruption from the area would likely not be Earth-directed, it could be very photogenic as tendrils of hot plasma fly into the black space above the edge of the Sun,” he adds.

This type of structures are nothing new to science, but what amazed researchers was its sheer size. Solar filaments develop from plasma, as the stuff rises into the solar corona. This is the outer layer of the star's atmosphere.

Counter-intuitively, the corona is significantly hotter than the rest of the Sun, and this is why the plasma threads appear to be darker than their surrounding. They are clearly visible when observers see them along the solar limb, which is the star's curving horizon.

SDO reveals that the newly-found filament is protruding out of the Sun's southwestern limb. The new manifestation is probably a part of the natural variation cycle that the star undergoes once ever 11 years.

Less than a year ago, the active phase of this cycle began, which translates into increased numbers of sunspots, solar storms and solar filaments. The star had researchers worried for a while, since the onset of this solar maximum was delayed by several months.

SDO, SOHO and other solar observatories are keeping an eye on the Sun as it awakens, hunting for signs of solar storms that may affect our planet. Satellites, the ISS, and power grids are usually susceptible to damage from such events.