Sketch of the relative positions of spacecraft that observed the 12 February coronal mass ejections (CME). ESA’s Solar Orbiter spacecraft was ‘behind’ the Sun from the perspective of Earth; the Earth was about 12 degrees west of Sun-centre as seen from Solar Orbiter. ESA’s Proba-2, which orbits the Earth, and the ESA/NASA Solar and Heliospheric Observatory (SOHO), which is located in orbit around the Lagrange point 1, 1.5 million km in front of the Earth towards the Sun, also viewed the CME. NASA’s STEREO-A (Solar Terrestrial Relations Observatory) also caught a glimpse of the event from its viewpoint away from the direct Sun-Earth line. Together the spacecraft provide valuable, different perspectives on the same event.
Not to scale