Transcripts of 10718_STEREO_sun360_-H264_1280x720_30

Sound Effect Sound Effect Music, Narrator: In 2006 NASA launched the Solar TErrestrial RElations Observatory, or STEREO, spacecraft. Over the last 4 years, the two spacecraft have slowly made their way along Earth's orbit, with STEREO A advancing ahead, and STEREO B falling behind. As they've separated, our view of the sun has increased. Other satellites near Earth, such as SOHO, and now SDO, continue to watch the sun from Earth's perspective, while the STEREO spacecraft see increasingly different views. Now STEREO A and B are almost exactly opposite each other and for the first time in human history, we have a view of the entire sun Music The sun has a huge influence on everyday life, and with our increased reliance on technology, this influence just keeps getting stronger. Coronal mass ejections and solar flares are the hurricanes of space weather and they have the power to disrupt our navigation systems, communications and even electrical grids, so it's vital we know when they are coming. Just as protecting our homes requires the best possible weather forecast, protecting these systems requires the best possible space weather forecast. Sunspots and other active regions on the sun can help predict a new round of such space weather, but before STEREO we were able to see only one side of the sun at a time; we couldn't tell what was starting to form on the far side. Since the sun takes about 27 days to rotate once, solar activity had plenty of time to build unnoticed. Scientists first began to get a sense of the far side with SOHO's Michelson Doppler Imager which worked almost like an ultrasound to give a view of the sun's back based on observations of the ripples on its front. Now STERE can make direct observations and eliminate any uncertainty about activity on the far side of the sun. This unprecedented view will last for at least another 8 years as the spacecraft slowly continue their journey. They will cross behind the sun, and then once again continue to opposite sides of the sun, this time with their position reversed. During that time, astronomers will be able to see magnetic active regions wherever they form on the sun, so we will know about regions on the far side well before any Earth-based observatory can see them. The full view of the sun from STEREO and SDO coupled with the other spacecraft in NASA's Heliophysics fleet, will help scientists understand our dynamic star and give us more time to prepare for the next big storm. Static static Sound Effect Sound Effect