Enormous loops of super-hot plasma, much bigger than the Earth, are seen raining down onto the surface of the Sun in a spectacular new video just released by NASA. The plasma rain was caught on film by NASA’s Solar Dynamics Observatory (SDO) last year when a mid-strength solar flare was released from the Sun on July 19th. The solar flare created the gigantic, shining plasma loops, which are also known as ‘coronal rain’.
“Hot plasma in the corona [the sun’s outer atmosphere] cooled and condensed along strong magnetic fields in the region,” NASA scientists said in a description of the video on Wednesday.
“Magnetic fields are invisible, but the charged plasma is forced to move along the lines, showing up brightly in the extreme ultraviolet wavelength of 304 Angstroms, and outlining the fields as it slowly falls back to the solar surface,” they added.
NASA’s SDO spacecraft has now just begun its third year in space, being launched back on February 11, 2010. The $850 million mission is planned to last for at least five years, during that time providing extremely detailed observations of the Sun, monitoring space weather, and helping research being done on solar flares and CMEs.
“SDO has delivered thus far, capturing more than 100 million images of our star as of late last year. Some of the spacecraft’s most memorable shots over the last year are highlighted in another video, which NASA released last week to celebrate the mission’s birthday.”
SDO has also provided new insight into grazing comets, such as Comet Lovejoy, a comet which survived a very close encounter with the Sun, traveling directly through its corona in December 2011. And should provide excellent quality observations of the two large comets expected later this year, Comet ISON and Comet PANSTARRS.
And has even allowed researchers to learns great deal more about about Venus’ atmosphere, using SDO to make observations “during the planet’s ‘transit’ across the sun’s face, from Earth’s perspective, in June of last year. The Venus transit transfixed skywatchers and researchers around the world, as the next one won’t come until 2117.”
In addition to SDO, NASA’s twin Stereo probes are also providing a means of observing the Sun, as does the Solar and Heliospheric Observatory, a collaboration between NASA and the European Space Agency (ESA).
Some more background on what plasma loops, also known as coronal loops, are:
“Coronal loops form the basic structure of the lower corona and transition region of the Sun. These highly structured loops are a direct consequence of the twisted solar magnetic flux within the solar body. The population of coronal loops can be directly linked with the solar cycle; it is for this reason coronal loops are often found with sunspots at their footpoints. The upwelling magnetic flux pushes through the photosphere, exposing the cooler plasma below. The contrast between the photosphere and the solar interior gives the impression of dark spots, or sunspots.”
“Coronal loops populate both active and quiet regions of the solar surface. Active regions on the solar surface take up small areas but produce the majority of activity and are often the source of flares and Coronal Mass Ejections due to the intense magnetic field present. Active regions produce 82% of the total coronal heating energy. Coronal holes are open field lines located predominantly in the polar regions of the Sun and are known to be the source of the fast solar wind. The quiet Sun makes up the rest of the solar surface. The quiet Sun, although less active than active regions, is awash with dynamic processes and transient events (bright points, nanoflares and jets). As a general rule, the quiet Sun exists in regions of closed magnetic structures, and active regions are highly dynamic sources of explosive events. It is important to note that observations suggest the whole corona is massively populated by open and closed magnetic fieldlines.”
Image Credits: NASA/SDO; Coronal Loop via Wikimedia Commons