Where were you a week ago on the March equinox (March 20, 2019)? The SOHO solar observatory was some 900,000 miles (1.5 million km) from Earth, orbiting the first Lagrange point (L1), monitoring the sun.
The above montage of images shows what SOHO saw early on equinox morning. The four images show the sun at different ultraviolet wavelengths. From left to right, the images shown in this view were taken at increasing wavelengths – 171 angstroms (Å), 195 Å, 284 Å and 304 Å, respectively – with SOHO’s Extreme ultraviolet Imaging Telescope, which currently takes snapshots of the sun twice a day.
Each wavelength channel is sensitive to solar material at a different range of temperatures, peering at different heights into the sun’s atmosphere. From left to right, the brightest material in each image corresponds to temperatures of 1 million, 1.5 million, 2 million and 60,000–80,000 degrees C (1.8 million, 2.7 million, 3.6 million and 100,000-144,000 F), respectively.
Bottom line: Four images of the sun by the SOHO solar observatory taken on the March 2019 equinox.
Eleanor Imster has helped write and edit EarthSky since 1995. She was an integral part of the award-winning EarthSky radio series almost since it began until it ended in 2013. Today, as Lead Editor at EarthSky.org, she helps present the science and nature stories and photos you enjoy. She also serves as one of the voices of EarthSky on social media platforms including Facebook, Twitter and G+. She and her husband live in Tennessee and have two grown sons.