The NASA Solar TErrestrial RElations Observatory (STEREO) mission consists of two identical spacecraft which were placed in two different orbits around the Sun. STEREO Ahead was placed slightly closer to the Sun than Earth and STEREO Behind slightly further away than Earth. This causes them to respectively pull farther ahead of and fall gradually behind Earth's orbit and thus exposing the farside of the Sun. On the site you will find data from the SECCHI instrument: the extreme ultraviolet imager (EUVI) camera showing the Sun in the 195 Ångström wavelength and two white-light coronagraphs: COR1 and COR2.
Communications with STEREO Behind were lost on October 1, 2014, due to multiple hardware anomalies affecting control of the spacecraft orientation. There is currently no real-time data available from STEREO Behind. Should communications be reestablished in the future we will feature any data coming from STEREO Behind on this page.
Just like DSCOVR, the STEREO mission has instruments on board (PLASTIC and IMPACT) to measure the composition of the solar wind and strength/direction of the interplanetary magnetic field at the space craft. Due to the location of STEREO Ahead, this data is of great use to see what kind of space weather conditions we could expect from any incoming coronal holes days in advance.
A lot of people come to SpaceWeatherLive to follow the Sun's activity or if there is aurora to be seen, but with more traffic comes higher server costs. Consider a donation if you enjoy SpaceWeatherLive so we can keep the website online!
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