STEREO spacecraft

About STEREO spacecraft: 

 

• The pair of STEREO (Solar TErrestrial RElations Observatory) spacecraft were launched on October 25, 2006, from Florida's Cape Canaveral Air Force Station.
• The two spacecraft were situated in Sun's orbit, STEREO-A ("Ahead") and STEREO-B ("Behind").
• The dual-spacecraft mission accomplished its major goal by delivering the first-ever stereoscopic view of our star. 
• On February 6, 2011, another significant milestone was achieved as both STEREO-A and -B reached a remarkable 180-degree separation in their orbits, which gave us the full sphere image of the Sun.
• Significance of STEREO-A
  • It will synthesize its views with those from Nasa's and the European Space Agency’s Solar and Heliospheric Observatory (SOHO) and Nasa’s Solar Dynamics Observatory (SDO).
  • Its distance from Earth changes throughout the flyby, it will optimize its stereo vision for different-sized solar features at different times, akin to adjusting the focus on a several million-mile-wide telescope.
  • It will allow scientists to understand how a coronal mass ejection's (CME) magnetic field evolves on its way to Earth.

 

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Q1) What is the heliosphere?

The heliosphere is a vast region of space surrounding the Sun where the solar wind, a stream of charged particles emanating from the Sun, interacts with the interstellar medium, which is the tenuous gas and dust that exists between stars in our galaxy.

Source: Spacecraft prepares for rare Earth flyby 17 years after it left planet