Launched in October 2006, STEREO traces the flow of energy and matter from the sun to Earth. It also provides unique and revolutionary views of the sun-Earth system. The mission observed the sun in 3-D for the first time in 2007. In 2009, the twin spacecraft revealed the 3-D structure of coronal mass ejections which are violent eruptions of matter from the sun that can disrupt communications, navigation, satellites and power grids on Earth.
Seeing?the whole sun front and back simultaneously will enable significant advances in space weather forecasting for Earth and for planning for future robotic and manned spacecraft missions throughout the solar system.
These views are the result of observations by NASA's two Solar TErrestrial Relations Observatory (STEREO) spacecraft. The duo are on diametrically opposite sides of the sun, 180 degrees apart. One is ahead of Earth in its orbit, the other trailing behind.
The STEREO mission consists of two spacecraft orbiting the Sun, one moving a bit faster than Earth and the other a little slower. In the time since the STEREO spacecraft entered these orbits near the beginning of 2007 they have been slowly separating. In Feb. 2011 they reach the point at which they are on opposite sides of the Sun and can observe the entire far side of the Sun.
Rotating solar sphere made from a combination of imagery from the two STEREO spacecraft, together with simultaneous data from the Solar Dynamic Observatory.
This movie is made from data taken on January 31, 2011. STEREO is able to take images like this once every ten minutes. Because the STEREO separation was still slightly less than 180 degrees at that time, the small gap on the far side of the Sun has been interpolated over to simulate the full 360 degree view that STEREO will see. This gap will start to disappear on February 6, 2011, and will completely disappear over the next several days. The regions near the seam between the STEREO Ahead and Behind images appear stretched out because they are at the edges of the Sun in the original images. As the STEREO spacecraft continue to move further around to the farside of the sun, imaging in this part of the globe will improve.
Credit: NASA/Goddard Space Flight Center/STEREO/SECCHI
Zoom in to solar activity visible on the far side of the Sun from the STEREO Behind spacecraft on January 13, 2011. The images show a young, fast-growing magnetic active region of the solar atmosphere which produces solar flares and ejections of material from the sun. These images were taken by STEREO's Extreme UltraViolet Imager (EUVI). The brightest, most active areas show material at temperatures as-high-as 1.8 million degrees C, while the quieter parts of the images show material at temperatures of only 80,000 deg C. This activity occurred on the far side of the sun and so could not be directly seen from Earth. The STEREO separation was still less than 180 degrees at that time, and the small gap on the far side of the Sun which would be briefly visible in the film has been interpolated over to simulate the full 360 degree view that STEREO will see.
Credit: NASA/Goddard Space Flight Center/STEREO/SECCHI
Active regions rotating from the observed front side of the Sun to the helioseismic reconstructed far-side and back again to the front side in October/November 2003. Large active regions were clearly visible in the helioseismic images. These particular ones were extremely active
and produced the well known Halloween solar storms.
Credit: NASA/Goddard Space Flight Center/MDI/GONG(NSO/NSF)/HMI
Farside direct observations from STEREO (left) and simultaneous helioseismic reconstructions (right). Medium to large size active regions clearly appear on the helioseismic images, however the smaller ones fall within the noise level. STEREO observations of the far-side will help calibrate and further improve the helioseismic technique.
Credit: NASA/Goddard Space Flight Center/SECCHI/GONG(NSO/NSF)/HMI
The need for space weather services has grown significantly in past years as the technology we rely on for everyday life has become increasingly vulnerable to space weather. America's vulnerability to space weather is rising fast as our national and global critical technology infrastructure becomes more complex and dependent on advance technology. These recent advances in our technological infrastructure drive emerging space weather service needs undreamed of just a decade ago. Our advanced technological infrastructure will face challenges from the increase in solar activity and are being addressed at the highest levels of government.
The critical observations from STEREO and SDO will help provide accurate and timely space weather storm warnings, and will aid greatly in our efforts to protect the technologies we have become so dependent in our daily activities. Measurements of coronal mass ejections from the STEREO spacecraft provide vital input for NOAA's space weather forecasters. Enlil is the first operational physics-based numerical space weather prediction model. Using STEREO input, the model computes the trajectory of solar storms between Sun and Earth, and provides forecasts of geomagnetic storms out to 96 hours.
Credit:WSA-Enlil Model: NOAA in partnership with AFW, AFRL (Nick Arge, WSAdeveloper), George Mason University (Dusan Odstrcil, Enlil modeldeveloper), NASA, NSF, and NRL.
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 126.96.36.199.0