STEREO Detect Impossibly Fast Solar Eruption

The twin components of the NASA Solar TErrestrial RElations Observatory (STEREO) mission were recently able to detect one of the fastest and largest solar eruptions in recent history. On August 1, the Sun released a massive amount of matter and radiation, which sped away from the star at a whooping 2.2 million miles per hour. Despite this massive speed, the two spacecrafts were able to detect the event, and send their conclusions back to Earth, where researchers confirmed the discovery.

The large solar flare triggered a massive eruption called a coronal mass ejection (CME). This is one of the most dangerous things that can go on in the star, experts say. CME produce massive amounts of highly-energetic particles, which have the effect of a heavy bombardment on Earth's protective layer, the magnetosphere. The entire force of the ejection was unleashed on our planet on Tuesday, August 3, and the main result was a heavy intensification of the northern lights, the Aurora Borealis. We got off easy this time, solar physicists say, as larger CME can have devastating effects on our infrastructure.

Representatives of the American space agency said in a recent statement that “these kinds of eruptions are one of the first signs that the Sun is waking up and heading toward another solar maximum expected in the 2013 time frame.” The star functions in 11-year-old cycles, each of which contains a solar maximum and a minimum. These periods are named according to the amount of solar activity (sunspots, solar flares, CME) that takes place on the Sun's surface. Over the past two years, the star should have exited the minimum stage, and begin resuming its activity. But the minimum persisted, and it's only now that the Sun is beginning to show signs of recovery.

STEREO is in a unique position to conduct very accurate observations of the solar surface, given that its twin spacecrafts allow for it to look at the Sun in 3D. This allows solar physicists to get a depth-of-view in their studies, that is impossible with any other telescope. Not even the Solar Dynamic Observatory (SDO), the most advanced Sun-watching instrument, can produce 3D views of its targets. STEREO is capable of doing this because its components fly apart from each other, providing independent views of the same event from two vantage points, Space reports.

STEREO Spies First Major Activity of Solar Cycle 24

STEREO (Behind) spacecraft observed a coronal mass ejection (CME) that erupted on the sun on May 5. Shocks accelerated by the CME produced a large Type II radio burst. The source of the CME is an active region (seen as a bright area in the green EUV 195 still) just rotating into view from STEREO Behind, and it is being followed by another.Credit: NASA/SOHO
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The COR-2 coronagraph video clip captured the CME in frames taken about every 30 minutes over about one day. Credit: NASA/SOHO
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NASA′s Solar Terrestrial Relations Observatory (STEREO) spacecraft has spotted the first major activity of the new solar cycle. On May 5 STEREO-B observed a Type II radio burst and a bright, fast coronal mass ejection (CME) emanating from the far side of the sun. The activity originated in a solar active region that rotated into view from Earth on May 8.

A Type II radio burst is a discharge of radio waves that are emitted when shocks are accelerated by a CME—the sudden eruption of energy and solar material.

The active region appears well above the sun′s equator, at about 30 degrees latitude, which indicates it is part of the new solar cycle. Activity from the previous solar cycle would appear nearer to the sun′s equator. These regions also have a distinct magnetic organization characteristic of new cycle regions.

″This is a really exciting opportunity to observe the first major outbreak of solar activity in Solar Cycle 24,″ says Joseph Gurman, the newly named project scientist for STEREO at Goddard Space Flight Center. Gurman officially takes the helm from current project scientist Michael Kaiser on June 1.

The last years of Solar Cycle 23 marked the longest and deepest solar minimum in 100 years. Its unusually small number of active regions and sunspots have led some impatient space-weather watchers to wonder if we were entering another ″Maunder minimum.″ That period, in the late 17th and early 18th centuries, saw few, if any, sunspot regions, and coincided with the deepest part of the ″Little Ice Age″ of global cooling.

The twin STEREO spacecraft each carry two instruments and two instrument suites, including the Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI). SECCHI consists of an extreme ultraviolet imager (EUVI), two visible-light coronagraphs (COR-1 and COR-2), and a heliospheric imager (HI). The radio bursts were observed by the SWAVES instrument, also included in the STEREO payload. The solar activity on May 5 was detected with the EUVI instrument aboard STEREO-B, the spacecraft that trails behind Earth in its orbit around the sun.

STEREO, the third mission in NASA′s Solar Terrestrial Probes series, launched on October 26, 2006. STEREO′s mission, now in the extended phase, is to provide the first-ever stereoscopic measurements to study the sun.

For more information about NASA’s STEREO mission, visit:
http://www.nasa.gov/stereo

For more information about the solar cycle, visit:
http://solarscience.msfc.nasa.gov/sunspotcycle.shtml

For more SOHO solar images, visit:
http://sohowww.nascom.nasa.gov/